INFORMATION NOTEINFORMATION NOTE N 016/12 2012-05-15 Page 2 of 2 Description of change: Old datasheet edition New datasheet edition BCR401W Datasheet edition Parameter Min. Typ. Max

INFORMATION NOTE

N° 016/12

2012-05-15 Page 1 of 2

Update of datasheets for LED drivers BCR401W, BCR402W, BCR401U,BCR402U, BCR320U/BCR321U, BCR420U/BCR421U

Subject of Change: Update of datasheets respective higher max. ratings of output voltage Vout,tighter limits of internal resistor Rint and tighter limits of output current Iout.

Products affected: BCR401WBCR402WBCR401UBCR402UBCR320UBCR321UBCR420UBCR421U

Reason of Change: 1. Electrical Changes Higher max. ratings of output voltage Vout for

BCR401W, BCR402W, BCR401U, BCR402U, BCR420U,BCR421U.

Tighter limits of internal resistor Rint for BCR401W,BCR402W, BCR401U, BCR402U, BCR320U, BCR321U,BCR420U, BCR421U.

Tighter limits of output current Iout for BCR320U,BCR321U, BCR420U, BCR421U.

Updated figures in data sheets of BCR402U,BCR420U, BCR421U.

See details of the changes on the next page.

2. Layout ChangesLayout of all affected datasheets updated according to new Infineontemplate.

INFORMATION NOTE

N° 016/12

2012-05-15 Page 2 of 2

Description of change: Old datasheet edition New datasheet edition

BCR401W Datasheet edition

Parameter Min. Typ. Max. Min. Typ. Max. Unit

Vout- - 16 - - 18 V

Rint66 79 94 68 79 90 Ω

BCR402W Datasheet edition


Vout- - 16 - - 18 V

Rint33 38 47 33 38 45 Ω

BCR401U Datasheet edition


Vout- - 38 - - 40 V

Rint72 91 110 78 91 104 Ω



Vout- - 38 - - 40 V

Rint37 44 53 38 44 52 Ω


BCR321U Parameter Min. Typ. Max. Min. Typ. Max. Unit

Rint65 90 105 85 95 105 Ω

Iout8 10 12 9 10 11 mA


BCR421U Parameter Min. Typ. Max. Min. Typ. Max. Unit

Vout- - 38 - - 40 V

Rint65 90 105 85 95 105 Ω

Iout8 10 12 9 10 11 mA

Changes are marked in red.

2010-01-12 2012-04-12

2010-01-12 2012-04-12

2009-07-31 2012-04-12

Update of Figure 3-13 BCR420U: Enable

Current versus VEN IEN = f(VEN)

8 Ω label updated on Figure 3-22

BCR421U: Output Current versus VEN Iout

= f(VEN)

2009-07-31 2012-04-13

2010-01-15 2012-05-04

2010-01-15 2012-05-04

Temperature labels updated on Figure 3-7

Output Current versus VS Iout = f(VS)

Temperature labels updated on Figure 3-8

Output Current versus Rext Iout = f(Rext)

Assessment: Due to the higher maximum ratings and tighter limits technicalperformance of the products is improved.

There is no impact on form, fit, function, reliability andprocessability.

Data sheets have been updated accordingly, see attachment3_cip01612.

Time schedule: Will be implemented on July 2, 2012 with datecode 1227 (YYWW)printed on the barcode product label.

If you have any questions, please do not hesitate to contact your local Sales office.

Power Management & Mult imarket

Datasheet Revision 2.0, 2012-05-04

BCR320U / BCR321U

LED Driver

Edition 2012-05-04Published byInfineon Technologies AG81726 Munich, Germany© 2012 Infineon Technologies AGAll Rights Reserved.

Legal DisclaimerThe information given in this document shall in no event be regarded as a guarantee of conditions or characteristics. With respect to any examples or hints given herein, any typical values stated herein and/or any information regarding the application of the device, Infineon Technologies hereby disclaims any and all warranties and liabilities of any kind, including without limitation, warranties of non-infringement of intellectual property rights of any third party.

InformationFor further information on technology, delivery terms and conditions and prices, please contact the nearest Infineon Technologies Office (www.infineon.com).

WarningsDue to technical requirements, components may contain dangerous substances. For information on the types in question, please contact the nearest Infineon Technologies Office.Infineon Technologies components may be used in life-support devices or systems only with the express written approval of Infineon Technologies, if a failure of such components can reasonably be expected to cause the failure of that life-support device or system or to affect the safety or effectiveness of that device or system. Life support devices or systems are intended to be implanted in the human body or to support and/or maintain and sustain and/or protect human life. If they fail, it is reasonable to assume that the health of the user or other persons may be endangered.

http://www.infineon.com

BCR320U / BCR321U

Datasheet 3 Revision 2.0, 2012-05-04

Trademarks of Infineon Technologies AGAURIX™, C166™, CanPAK™, CIPOS™, CIPURSE™, EconoPACK™, CoolMOS™, CoolSET™,CORECONTROL™, CROSSAVE™, DAVE™, DI-POL™, EasyPIM™, EconoBRIDGE™, EconoDUAL™,EconoPIM™, EconoPACK™, EiceDRIVER™, eupec™, FCOS™, HITFET™, HybridPACK™, I²RF™,ISOFACE™, IsoPACK™, MIPAQ™, ModSTACK™, my-d™, NovalithIC™, OptiMOS™, ORIGA™,POWERCODE™; PRIMARION™, PrimePACK™, PrimeSTACK™, PRO-SIL™, PROFET™, RASIC™,ReverSave™, SatRIC™, SIEGET™, SINDRION™, SIPMOS™, SmartLEWIS™, SOLID FLASH™, TEMPFET™,thinQ!™, TRENCHSTOP™, TriCore™.

Other TrademarksAdvance Design System™ (ADS) of Agilent Technologies, AMBA™, ARM™, MULTI-ICE™, KEIL™,PRIMECELL™, REALVIEW™, THUMB™, µVision™ of ARM Limited, UK. AUTOSAR™ is licensed by AUTOSARdevelopment partnership. Bluetooth™ of Bluetooth SIG Inc. CAT-iq™ of DECT Forum. COLOSSUS™,FirstGPS™ of Trimble Navigation Ltd. EMV™ of EMVCo, LLC (Visa Holdings Inc.). EPCOS™ of Epcos AG.FLEXGO™ of Microsoft Corporation. FlexRay™ is licensed by FlexRay Consortium. HYPERTERMINAL™ ofHilgraeve Incorporated. IEC™ of Commission Electrotechnique Internationale. IrDA™ of Infrared DataAssociation Corporation. ISO™ of INTERNATIONAL ORGANIZATION FOR STANDARDIZATION. MATLAB™ ofMathWorks, Inc. MAXIM™ of Maxim Integrated Products, Inc. MICROTEC™, NUCLEUS™ of Mentor GraphicsCorporation. MIPI™ of MIPI Alliance, Inc. MIPS™ of MIPS Technologies, Inc., USA. muRata™ of MURATAMANUFACTURING CO., MICROWAVE OFFICE™ (MWO) of Applied Wave Research Inc., OmniVision™ ofOmniVision Technologies, Inc. Openwave™ Openwave Systems Inc. RED HAT™ Red Hat, Inc. RFMD™ RFMicro Devices, Inc. SIRIUS™ of Sirius Satellite Radio Inc. SOLARIS™ of Sun Microsystems, Inc. SPANSION™of Spansion LLC Ltd. Symbian™ of Symbian Software Limited. TAIYO YUDEN™ of Taiyo Yuden Co.TEAKLITE™ of CEVA, Inc. TEKTRONIX™ of Tektronix Inc. TOKO™ of TOKO KABUSHIKI KAISHA TA. UNIX™of X/Open Company Limited. VERILOG™, PALLADIUM™ of Cadence Design Systems, Inc. VLYNQ™ of TexasInstruments Incorporated. VXWORKS™, WIND RIVER™ of WIND RIVER SYSTEMS, INC. ZETEX™ of DiodesZetex Limited.Last Trademarks Update 2011-11-11

Revision HistoryPage or Item Subjects (major changes since previous revision)Revision 2.0, 2012-05-04All Datasheet layout updatedTable 2-3 Rint limits tightenedTable 2-3 Iout limits tightened

BCR320U / BCR321U

Table of Contents


Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

1 LED Driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71.2 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71.3 General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2 Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

3 Typical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

4 Application hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

5 Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Table of Contents

BCR320U / BCR321U

List of Figures


Figure 1-1 Pin configuration and typical application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Figure 3-1 Total Power Dissipation Ptot = f(TS). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Figure 3-2 Permissible Pulse Load RthJS = f(tp) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Figure 3-3 Permissible Pulse Load Ptotmax / PtotDC= f(tp) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Figure 3-4 BCR320U: Output Current versus Vout Iout = f(Vout), VEN = 12 V, Rext = Parameter . . . . . . . . . . . . . 13Figure 3-5 BCR320U: Output Current versus Rext Iout = f(Rext), VEN = 12 V, Vout = Parameter . . . . . . . . . . . . . 13Figure 3-6 BCR320U: Output Current versus Vout Iout = f(Vout), VEN = 12 V, Rext = open, TA = Parameter . . . . 14Figure 3-7 BCR320U: Output Current versus Vout Iout = f(Vout), VEN = 12 V, Rext = 20 Ω, TA = Parameter . . . . 14Figure 3-8 BCR320U: Output Current versus Vout Iout = f(Vout), VEN = 12 V, Rext = 3 Ω, TA = Parameter . . . . . 15Figure 3-9 BCR320U: Output Current versus VEN Iout = f(VEN), Vout = 2 V, Rext = open, TA = Parameter . . . . . 15Figure 3-10 BCR320U: Output Current versus VEN Iout = f(VEN), Vout = 2 V, Rext = 20 Ω, TA = Parameter . . . . . 16Figure 3-11 BCR320U: Output Current versus VEN Iout = f(VEN), Vout = 2 V, Rext = 3 Ω, TA = Parameter . . . . . . 16Figure 3-12 BCR320U: Output Current versus VEN Iout = f(VEN), Vout = 2 V, Rext = Parameter . . . . . . . . . . . . . . 17Figure 3-13 BCR320U: Enable Current versus VEN IEN = f(VEN), Rext = open, Iout = 0 A, TA = Parameter . . . . . 17Figure 3-14 BCR321U: Output Current versus Vout Iout = f(Vout), VEN = 3.3 V, Rext = Parameter . . . . . . . . . . . . 18Figure 3-15 BCR321U: Output Current versus Rext Iout = f(Rext), VEN = 3.3 V, Vout = Parameter . . . . . . . . . . . . 18Figure 3-16 BCR321U: Output Current versus Vout Iout = f(Vout), VEN = 3.3 V, Rext = open, TA = Parameter . . . 19Figure 3-17 BCR321U: Output Current versus Vout Iout = f(Vout), VEN = 3.3 V, Rext = 20 Ω, TA = Parameter. . . . 19Figure 3-18 BCR321U: Output Current versus Vout Iout = f(Vout), VEN = 3.3 V, Rext = 3 Ω, TA = Parameter. . . . . 20Figure 3-19 BCR321U: Output Current versus VEN Iout = f(VEN), Vout = 2 V, Rext = open, TA = Parameter . . . . . 20Figure 3-20 BCR321U: Output Current versus VEN Iout = f(VEN), Vout = 2 V, Rext = 20 Ω, TA = Parameter . . . . . 21Figure 3-21 BCR321U: Output Current versus VEN Iout = f(VEN), Vout = 2 V, Rext = 3 Ω, TA = Parameter . . . . . . 21Figure 3-22 BCR321U: Output Current versus VEN Iout = f(VEN), Vout = 2 V, Rext = Parameter . . . . . . . . . . . . . . 22Figure 3-23 BCR321U: Enable Current versus VEN IEN = f(VEN), Rext = open, Iout = 0 A, TA = Parameter . . . . . 22Figure 4-1 Application Circuit: Enabling / PWM by Micro Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23Figure 4-2 Application Circuit: Enabling by Connecting to VS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23Figure 5-1 Package Outline for SC74 (dimensions in mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Figure 5-2 Package Footprint for SC74 (dimensions in mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Figure 5-3 Tape and Reel Information for SC74 (dimensions in mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

List of Figures

BCR320U / BCR321U

List of Tables


Table 2-1 Maximum Ratings at TA = 25 °C, unless otherwise specified . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Table 2-2 Thermal Resistance at TA = 25 °C, unless otherwise specified. . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Table 2-3 Electrical Characteristics at TA = 25 °C, unless otherwise specified . . . . . . . . . . . . . . . . . . . . . . . . 9Table 2-4 DC Characteristics with stabilized LED load at TA = 25 °C, unless otherwise specified . . . . . . . . 10

List of Tables

BCR320U / BCR321U

LED Driver


1 LED Driver

1.1 Features

1.2 Applications• Architectural LED lighting• Channel letters for advertising, LED strips for decorative lighting• Retail lighting in fridge, freezer case and vending machines• Emergency lighting (e.g. steps lighting, exit way signs etc.)

1.3 General DescriptionThe BCR320U / BCR321U provides a low-cost solution for driving 0.5 W LEDs with a typical LED current of150 mA to 200 mA. Internal breakdown voltage is higher than 16 V which is the maximum voltage the LED drivercan sustain when the output is directly connected to supply voltage.The BCR320U / BCR321U can be operated with a supply voltage of more than 16 V considering the voltage dropof the LED load which reduces the output voltage to the maximum rating of the driver.The enable pin of BCR320U can withstand a maximum voltage of 25 V which can be increased adding a seriesresistor in front of the enable pin reducing the voltage at the enable pin below 25 V.The digital input pin of BCR321U allows dimming via a micro controller with frequencies up to 10 kHz.A reduction of the output current at higher temperatures is the result of the negative temperature coefficient of -0.2 %/K of the LED driver.With no need for additional external components like inductors, capacitors and free wheeling diodes, theBCR320U / BCR321U LED drivers are a cost-efficient and PCB-area saving solution for driving 0.5 W LEDs.

• LED drive current preset to 10 mA• Continuous output current up to 250 mA with an external resistor• Easy paralleling of drivers to increase current• Supply voltage up to 25 V• Low side current control• Digital PWM input up to 10 kHz frequency (BCR321U)• Up to 1 W power dissipation in a small SC74 package• Negative thermal coefficient of -0.2 %/K reduces output current at higher temperatures• RoHS compliant (Pb-free) package• Automotive qualified according AEC Q101

SC74-3D

BCR320U / BCR321U

LED Driver


Figure 1-1 Pin configuration and typical application

Type Marking Pin Configuration PackageBCR320U 30 1 = EN 2; 3; 5 = OUT 4 = GND 6 = Rext SC74BCR321U 31 1 = EN 2; 3; 5 = OUT 4 = GND 6 = Rext SC74

Pin Configuration Typical Application

EN OUT

Rext

GND

+VS

Vdrop

2,3,51

6

4

IoutIEN

BCR320 U

EN

OUT

OUT GND

OUT

Rext1

2

3 4

5

6

Rext(optional )

BCR320U / BCR321U

Electrical Characteristics


2 Electrical Characteristics

Attention: Stresses above the max. values listed here may cause permanent damage to the device. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Maximum ratings are absolute ratings; exceeding only one of these values may cause irreversible damage to the integrated circuit.

Table 2-1 Maximum Ratings at TA = 25 °C, unless otherwise specifiedParameter Symbol Values Unit Note / Test Condition

Min. Typ. Max.Enable voltageBCR320UBCR321U

VEN--

--

254.5

V

Output current Iout - - 300 mAOutput voltage Vout - - 16 VReverse voltage between all terminals VR - - 0.5 VTotal power dissipation Ptot - - 1000 mW TS ≤ 100 °CJunction temperature TJ - - 150 °CStorage temperature range TSTG -65 - 150 °C

Table 2-2 Thermal Resistance at TA = 25 °C, unless otherwise specifiedParameter Symbol Values Unit Note / Test Condition

Min. Typ. Max.Junction - soldering point1)

1) For calculation of RthJA please refer to Application Note AN077 (Thermal Resistance Calculation)RthJS - - 50 K/W

Table 2-3 Electrical Characteristics at TA = 25 °C, unless otherwise specifiedParameter Symbol Values Unit Note / Test Condition

Min. Typ. Max.Collector-emitter breakdown voltage VBR(CEO) 16 - - V IC = 1 mA, IB = 0Enable currentBCR320UBCR321U

IEN--

1.2 1.2

--

mAVEN = 12 VVEN = 3.3 V

DC current gain hFE 200 350 500 - IC = 50 mA, VCE = 1 VInternal resistor Rint 85 95 105 Ω IRint = 10 mABias resistorBCR320UBCR321U

RB--

101.5

--

kΩ

BCR320U / BCR321U



Output currentBCR320UBCR321UOutput current at Rext = 3 ΩBCR320UBCR321U

Iout9 9

--

10 10

250 250

1111

--

mA Vout = 1.4 VVEN = 12 VVEN = 3.3 VVout > 1.4 VVEN = 12 VVEN = 3.3 V

Voltage drop (VRext) Vdrop 0.85 0.95 1.05 V Iout = 10 mA

Table 2-4 DC Characteristics with stabilized LED load at TA = 25 °C, unless otherwise specifiedParameter Symbol Values Unit Note / Test Condition

Min. Typ. Max.Lowest sufficient supply voltage overhead VSmin - 1.4 - V Iout > 18 mAOutput current change versusTABCR320UBCR321U

∆Iout/Iout--

-0.2-0.2

--

%/K Vout > 2.0 VVEN = 12 VVEN = 3.3 V

Output current change versus VSBCR320UBCR321U

∆Iout/Iout--

11

--

%/V Vout > 2.0 VVEN = 12 VVEN = 3.3 V

Table 2-3 Electrical Characteristics at TA = 25 °C, unless otherwise specified (cont’d)

Parameter Symbol Values Unit Note / Test ConditionMin. Typ. Max.

BCR320U / BCR321U

Typical characteristics


3 Typical characteristics

Figure 3-1 Total Power Dissipation Ptot = f(TS)

Figure 3-2 Permissible Pulse Load RthJS = f(tp)

0

200

400

600

800

1000

1200

0 20 40 60 80 100 120 140

Pto

t [m

W]

TS [°C]

0.1

1

10

100

10-6

10-5

10-4

10-3

10-2

10-1

100

Rth

JS [

K/W

]

tp [s]

D = 0D = 0.005D = 0.01D = 0.02D = 0.05D = 0.1D = 0.2D = 0.5

BCR320U / BCR321U



Figure 3-3 Permissible Pulse Load Ptotmax / PtotDC= f(tp)

1

10

100

1000

10-6

10-5

10-4

10-3

10-2

10-1

100

Pto

tma

x /

Pto

tDC

tp [s]

D = 0D = 0.005D = 0.01D = 0.02D = 0.05D = 0.1D = 0.2D = 0.5

BCR320U / BCR321U



Figure 3-4 BCR320U: Output Current versus Vout Iout = f(Vout), VEN = 12 V, Rext = Parameter

Figure 3-5 BCR320U: Output Current versus Rext Iout = f(Rext), VEN = 12 V, Vout = Parameter

0

0.1

0.2

0.3

0 1 2 3 4 5 6 7 8 9 10 11 12

Io

ut [A

]

Vout [V]

Rext = open

Rext = 20 Ω

Rext = 10 Ω

Rext = 6 Ω

Rext = 4 Ω

Rext = 3 Ω

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

1 10 100

Io

ut [A

]

Rext [Ω]

Vout = 1.4 VVout = 5.4 V

BCR320U / BCR321U



Figure 3-6 BCR320U: Output Current versus Vout Iout = f(Vout), VEN = 12 V, Rext = open, TA = Parameter

Figure 3-7 BCR320U: Output Current versus Vout Iout = f(Vout), VEN = 12 V, Rext = 20 Ω, TA = Parameter

0

0.005

0.01

0.015

0 2 4 6 8 10 12

Io

ut [A

]

Vout [V]

-40 °C25 °C85 °C

0

0.01

0.02

0.03

0.04

0.05

0.06

0 2 4 6 8 10 12

Io

ut [A

]

Vout [V]

-40 °C25 °C85 °C

BCR320U / BCR321U




Figure 3-9 BCR320U: Output Current versus VEN Iout = f(VEN), Vout = 2 V, Rext = open, TA = Parameter

0

0.1

0.2

0.3

0 2 4 6 8 10 12

Io

ut [A

]

Vout [V]

-40 °C25 °C85 °C

0

0.005

0.01

0.015

0 5 10 15 20 25

Io

ut [A

]

VEN [V]

-40 °C25 °C85 °C

BCR320U / BCR321U



Figure 3-10 BCR320U: Output Current versus VEN Iout = f(VEN), Vout = 2 V, Rext = 20 Ω, TA = Parameter


0

0.01

0.02

0.03

0.04

0.05

0.06

0 5 10 15 20 25

Io

ut [A

]

VEN [V]

-40 °C25 °C85 °C

0

0.1

0.2

0.3

0 5 10 15 20 25

Io

ut [A

]

VEN [V]

-40 °C25 °C85 °C

BCR320U / BCR321U



Figure 3-12 BCR320U: Output Current versus VEN Iout = f(VEN), Vout = 2 V, Rext = Parameter

Figure 3-13 BCR320U: Enable Current versus VEN IEN = f(VEN), Rext = open, Iout = 0 A, TA = Parameter

0

0.1

0.2

0.3

0 5 10 15 20 25

Io

ut [A

]

VEN [V]

Rext = openRext = 20 ΩRext = 10 ΩRext = 6 ΩRext = 4 ΩRext = 3 Ω

0

0.5

1

1.5

2

2.5

3

0 5 10 15 20 25

IE

N [

mA

]

VEN [V]

-40 °C25 °C80 °C

BCR320U / BCR321U



Figure 3-14 BCR321U: Output Current versus Vout Iout = f(Vout), VEN = 3.3 V, Rext = Parameter

Figure 3-15 BCR321U: Output Current versus Rext Iout = f(Rext), VEN = 3.3 V, Vout = Parameter

0

0.1

0.2

0.3

0 1 2 3 4 5 6 7 8 9 10 11 12

Io

ut [A

]

Vout [V]

Rext = open

Rext = 20 Ω

Rext = 10 Ω

Rext = 6 Ω

Rext = 4 Ω

Rext = 3 Ω

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

1 10 100

Io

ut [A

]

Rext [Ω]


BCR320U / BCR321U



Figure 3-16 BCR321U: Output Current versus Vout Iout = f(Vout), VEN = 3.3 V, Rext = open, TA = Parameter

Figure 3-17 BCR321U: Output Current versus Vout Iout = f(Vout), VEN = 3.3 V, Rext = 20 Ω, TA = Parameter

0

0.005

0.01

0.015

0 2 4 6 8 10 12

Io

ut [A

]

Vout [V]

-40 °C25 °C85 °C

0

0.01

0.02

0.03

0.04

0.05

0.06

0 2 4 6 8 10 12

Io

ut [A

]

Vout [V]

-40 °C25 °C85 °C

BCR320U / BCR321U





0

0.1

0.2

0.3

0 2 4 6 8 10 12

Io

ut [A

]

Vout [V]

-40 °C25 °C85 °C

0

0.005

0.01

0.015

0 1 2 3 4 5

Io

ut [A

]

VEN [V]

-40 °C25 °C85 °C

BCR320U / BCR321U





0

0.01

0.02

0.03

0.04

0.05

0.06

0 1 2 3 4 5

Io

ut [A

]

VEN [V]

-40 °C25 °C85 °C

0

0.1

0.2

0.3

0 1 2 3 4 5

Io

ut [A

]

VEN [V]

-40 °C25 °C85 °C

BCR320U / BCR321U





0

0.1

0.2

0.3

0 1 2 3 4 5 6

Io

ut [A

]

VEN [V]


0

1

2

3

4

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6

IE

N [

mA

]

VEN [V]

-40 °C25 °C80 °C

BCR320U / BCR321U

Application hints


4 Application hints

Figure 4-1 Application Circuit: Enabling / PWM by Micro Controller

Figure 4-2 Application Circuit: Enabling by Connecting to VS

Application hintsBCR320U / BCR321U serve as an easy to use constant current sources for LEDs. In stand alone application anexternal resistor can be connected to adjust the current from 10 mA to 250 mA. Rext can be determined by usingFigure 3-5 or Figure 3-15. Connecting a low tolerance resistor Rext will improve the overall accuracy of the currentsense resistance formed by the parallel connection of Rint and Rext leading to an improved current accuracy. Pleasetake into account that the resulting output currents will be slightly lower due to the self heating of the componentand the negative thermal coefficient.Please visit our web site www.infineon.com/lowcostleddriver for application notes and for up-to-dateapplication information.

EN OUT

Rext

GND

+VS

2,3,51

IoutIEN

BCR321 U

µC

Vdrop

6

4

Rext(optional )

EN OUT

Rext

GND

+VS

Vdrop

2,3,51

6

4

IoutIEN

BCR320U

Rext(optional )

http://www.infineon.com/lowcostleddriver

BCR320U / BCR321U

Package


5 Package

Figure 5-1 Package Outline for SC74 (dimensions in mm)

Figure 5-2 Package Footprint for SC74 (dimensions in mm)

Figure 5-3 Tape and Reel Information for SC74 (dimensions in mm)

SC74-PO V04

5 46

321

1.1 MAX.

(0.35)

(2.25)±0.22.9

B

0.2+0.1-0.050.35

Pin 1marking

M B 6x0.95

1.9

0.15 -0.06+0.1

1.6

A

±0.1

2.5

0.25

±0.1

±0.1

A0.2 M

0.1 MAX.

0.5

0.95

1.9

2.9

SC74-FPR V04

SC74-TP

2.7

4

3.15Pin 1marking

8

0.2

1.15

BCR320U / BCR321U

Terminology


Terminology

∆Iout/Iout Output current changehFE DC current gainIEN Enable currentIout Output currentIR Reverse currentLED Light Emitting DiodePCB Printed Circuit BoardPtot Total power dissipationPWM Pulse Width ModulationRB Bias resistorRext External resistorRint Internal resistorRoHs Restriction of Hazardous Substance directiveRthJS Thermal resistance junction to soldering pointTA Ambient temperatureTJ Junction temperatureTS Soldering point temperatureTstg Storage temperatureVBR(CEO) Collector-emitter breakdown voltageVBR Breakdown voltageVdrop Voltage dropVEN Enable voltageVout Output voltageVR Reverse voltageVS Supply voltageVSmin Lowest sufficient supply voltage overhead

Published by Infineon Technologies AG

w w w . i n f i n e o n . c o m




BCR401U

LED Driver






BCR401U




Revision HistoryPage or Item Subjects (major changes since previous revision)Revision 2.0, 2012-04-12All Datasheet layout updatedTable 2-1 Vout limit increasedTable 2-3 Rint limits tightened

BCR401U

Table of Contents



List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6





5 Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Table of Contents

BCR401U

List of Figures


Figure 1-1 Pin configuration and typical application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Figure 3-1 Total Power Dissipation Ptot = f(TS). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Figure 3-2 Permissible Pulse Load RthJS = f(tp) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Figure 3-3 Permissible Pulse Load Ptotmax / PtotDC= f(tp) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Figure 3-4 Output Current versus VS Iout = f(VS), VS - Vout = 1.4 V, Rext = Parameter. . . . . . . . . . . . . . . . . . . . 11Figure 3-5 Supply Current versus VS IS = f(VS), TA = Parameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Figure 3-6 Output Current versus VS Iout = f(VS), VS - Vout = Parameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Figure 3-7 Output Current versus VS Iout = f(VS), VS - Vout = 1.4 V, TA = Parameter. . . . . . . . . . . . . . . . . . . . . 13Figure 3-8 Output Current versus Rext Iout = f(Rext), VS = 10 V, VS - Vout = 1.4 V, TA = Parameter . . . . . . . . . . 13Figure 3-9 Output Current versus TS Iout = f(TS), VS = 10 V, VS - Vout = 1.4 V, Rext = Parameter . . . . . . . . . . . 14Figure 3-10 Reference Voltage Vdrop versus Iout Vdrop = f(Iout), Iout = 10 µA to 10 mA . . . . . . . . . . . . . . . . . . . . . 14Figure 3-11 Reference Voltage Vdrop versus Iout Vdrop = f(Iout), Iout = 10 mA to 65 mA. . . . . . . . . . . . . . . . . . . . . 15Figure 4-1 Application Circuit: Stand alone current source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16Figure 4-2 Application Circuit: Boost mode current source with external power transistor . . . . . . . . . . . . . . . 16Figure 5-1 Package Outline for SC74 (dimensions in mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Figure 5-2 Package Footprint for SC74 (dimensions in mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Figure 5-3 Tape and Reel Information for SC74 (dimensions in mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

List of Figures

BCR401U

List of Tables


Table 2-1 Maximum Ratings at TA = 25 °C, unless otherwise specified . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Table 2-2 Thermal Resistance at TA = 25 °C, unless otherwise specified. . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Table 2-3 Electrical Characteristics at TA = 25 °C, unless otherwise specified . . . . . . . . . . . . . . . . . . . . . . . . 9Table 2-4 DC Characteristics with stabilized LED load at TA = 25 °C, unless otherwise specified . . . . . . . . . 9

List of Tables

BCR401U

LED Driver


1 LED Driver

1.1 Features

1.2 Applications• Channel letters for advertising, LED strips for decorative lighting• Aircraft, train, ship illumination• Retrofits for general lighting, white goods like refrigerator lighting• Medical lighting• Automotive applications like CHMSL and rear combination lights

1.3 General DescriptionThe BCR401U is a cost efficient LED driver to drive low power LEDs. The advantages towards resistor biasing are:• homogenous light output despite varying forward voltages in different LED strings• homogenous light output of LEDs despite voltage drop across long supply lines• homogenous light output independent from supply voltage variations• longer lifetime of the LEDs due to reduced output current at higher temperatures (negative thermal coefficient)The advantages towards discrete solutions are:• lower assembly cost• smaller form factor• higher reliability due to less soldering joints• higher output current accuracy due to pretested LED driversDimming is possible by using an external digital transistor at the ground pin.The BCR401U can be operated at higher supply voltages by putting LEDs between the supply voltage VS and thepower supply pin of the LED driver. You can find further details in our application notes.The BCR401U is a perfect fit for numerous low power LED applications by combining small form factor with lowcost. These LED drivers offer several advantages to resistors like significantly higher current control at very lowvoltage drop ensuring high lifetime of the LEDs.

• LED drive current preset to 10 mA• Output current adjustable up to 65 mA with an external resistor• Easy paralleling of drivers to increase current• Supply voltage up to 40 V• High current accuracy at supply voltage variation• Low voltage overhead of 1.4 V• Up to 750 mW power dissipation in a small SC74 package• Negative thermal coefficient of -0.2 %/K reduces output current at higher temperatures• RoHS compliant (Pb-free) package• Automotive qualified according AEC Q101

SC74-3D

BCR401U

LED Driver



Type Marking Pin Configuration PackageBCR401U L1s 1 = GND 2; 3; 5 = OUT 4 = VS 6 = Rext SC74


GND

OUT

OUT VS

OUT

Rext1

2

3 4

5

6

GND OUT

+VS

Vdrop

2,3,51

IoutIS

Rext

VS

6

4

Rext

(optional )

BCR401U






Min. Typ. Max.Supply voltage VS - - 40 VOutput current Iout - - 65 mAOutput voltage Vout - - 40 VReverse voltage between all terminals VR - - 0.5 VTotal power dissipation Ptot - - 750 mW TS ≤ 112.5 °CJunction temperature TJ - - 150 °CStorage temperature range TSTG -65 - 150 °C





Min. Typ. Max.Collector-emitter breakdown voltage VBR(CEO) 40 - - V IC = 1 mA, IB = 0Supply current IS 340 420 500 µA VS = 10 VDC current gain hFE 100 220 470 - IC = 50 mA, VCE = 1 VInternal resistor Rint 78 91 104 Ω IRint = 10 mAOutput current Iout 9 10 11 mA VS = 10 V

Vout = 8.6 VVoltage drop (VRext) Vdrop 0.82 0.91 1 V Iout = 10 mA


Min. Typ. Max.Lowest sufficient supply voltage overhead VSmin - 1.4 - V Iout > 18 mAOutput current change versusTA ∆Iout/Iout - -0.2 - %/K VS = 10 VOutput current change versus VS ∆Iout/Iout - 1 - %/V VS = 10 V

BCR401U






0

200

400

600

800

1000

0 20 40 60 80 100 120 140

Pto

t [m

W]

TS [°C]

0.1

1

10

100

10-6

10-5

10-4

10-3

10-2

10-1

100

Rth

JS [

K/W

]

tp [s]

D = 0D = 0.005D = 0.01D = 0.02D = 0.05D = 0.1D = 0.2D = 0.5

BCR401U




1

10

100

1000

10-6

10-5

10-4

10-3

10-2

10-1

100

Pto

tma

x /

Pto

tDC

tp [s]

D = 0D = 0.005D = 0.01D = 0.02D = 0.05D = 0.1D = 0.2D = 0.5

BCR401U



Figure 3-4 Output Current versus VS Iout = f(VS), VS - Vout = 1.4 V, Rext = Parameter

Figure 3-5 Supply Current versus VS IS = f(VS), TA = Parameter

1

10

100

0 5 10 15 20 25 30 35 40

IO

UT [

mA

]

VS [V]

REXT = openREXT = 100 ΩREXT = 47 ΩREXT = 33 ΩREXT = 22 ΩREXT = 18 ΩREXT = 15 Ω

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

0 5 10 15 20 25 30 35 40

IS [

mA

]

VS [V]

80 °C20 °C

-40 °C

BCR401U



Figure 3-6 Output Current versus VS Iout = f(VS), VS - Vout = Parameter

Figure 3-7 Output Current versus VS Iout = f(VS), VS - Vout = 1.4 V, TA = Parameter

7

7.5

8

8.5

9

9.5

10

10.5

11

11.5

12

0 5 10 15 20 25 30 35 40

Io

ut [m

A]

VS [V]

1 V1.4 - 2 V

1

10

100

0 5 10 15 20 25 30 35 40

Io

ut [m

A]

VS [V]

-40 °C25 °C85 °C

150 °C

BCR401U



Figure 3-8 Output Current versus Rext Iout = f(Rext), VS = 10 V, VS - Vout = 1.4 V, TA = Parameter

Figure 3-9 Output Current versus TS Iout = f(TS), VS = 10 V, VS - Vout = 1.4 V, Rext = Parameter

10

100

10 100

Io

ut [m

A]

Rext [Ω]

-40 °C25 °C85 °C

150 °C

0

10

20

30

40

50

60

70

-50 -25 0 25 50 75 100 125 150

Io

ut [m

A]

TS [°C]

Rext = open

Rext = 100Ω

Rext = 47 ΩRext = 33 Ω

Rext = 22 ΩRext = 18 ΩRext = 15 Ω

BCR401U



Figure 3-10 Reference Voltage Vdrop versus Iout Vdrop = f(Iout), Iout = 10 µA to 10 mA

Figure 3-11 Reference Voltage Vdrop versus Iout Vdrop = f(Iout), Iout = 10 mA to 65 mA

0.8

0.85

0.9

0.95

1

1.05

1.1

10-5

10-4

10-3

10-2

Vd

rop [

V]

IOUT [A]

typ.min., max.

0.6

0.65

0.7

0.75

0.8

0.85

0.9

0.95

1

10 20 30 40 50 60 70

Vd

rop [

V]

IOUT [mA]

typ.min., max.

BCR401U

Application hints


4 Application hints

Figure 4-1 Application Circuit: Stand alone current source

Figure 4-2 Application Circuit: Boost mode current source with external power transistor

Application hintsBCR401U serves as an easy to use constant current source for LEDs. In stand alone application an externalresistor Rext can be connected to adjust the current between 10 mA and 65 mA. Rext can be determined by usingFigure 3-8. Connecting a low tolerance resistor Rext will improve the overall accuracy of the current senseresistance formed by the parallel connection of Rint and Rext leading to an improved current accuracy. Please takeinto account that the resulting output currents will be slightly lower due to the self heating of the component andthe negative thermal coefficient.In boost mode configuration the LED current can be extended to drive high power LEDs. Please visit our web sitewww.infineon.com/lowcostleddriver for detailed application notes.

GND OUT

+VS

Vdrop

2,3,51

IoutIS

Rext

VS

6

4

Rext

(optional )

GND OUT

+VS

Vdrop

2,3,51

Iout

IS

Rext

VS

6

4

ILED

R1

R2

Rext

(optional )


BCR401U

Package


5 Package




SC74-PO V04

5 46

321

1.1 MAX.

(0.35)

(2.25)±0.22.9

B

0.2+0.1-0.050.35

Pin 1marking

M B 6x0.95

1.9

0.15 -0.06+0.1

1.6

A

±0.1

2.5

0.25

±0.1

±0.1

A0.2 M

0.1 MAX.

0.5

0.95

1.9

2.9

SC74-FPR V04

SC74-TP

2.7

4

3.15Pin 1marking

8

0.2

1.15

BCR401U

Terminology


Terminology

∆Iout/Iout Output current changehFE DC current gainIEN Enable currentILED LED currentIout Output currentIR Reverse currentLED Light Emitting DiodePCB Printed Circuit BoardPtot Total power dissipationPWM Pulse Width ModulationRB Bias resistorRext External resistorRint Internal resistorRoHs Restriction of Hazardous Substance directiveRthJS Thermal resistance junction to soldering pointTA Ambient temperatureTJ Junction temperatureTS Soldering point temperatureTstg Storage temperatureVBR(CEO) Collector-emitter breakdown voltageVBR Breakdown voltageVdrop Voltage dropVout Output voltageVR Reverse voltageVS Supply voltageVSmin Lowest sufficient supply voltage overhead






BCR401W

LED Driver






BCR401W





BCR401W

Table of Contents



List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6





5 Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Table of Contents

BCR401W

List of Figures


Figure 1-1 Pin configuration and typical application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Figure 3-1 Total Power Dissipation Ptot = f(TS). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Figure 3-2 Permissible Pulse Load RthJS = f(tp) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Figure 3-3 Permissible Pulse Load Ptotmax / PtotDC= f(tp) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Figure 3-4 Output Current versus VS Iout = f(VS), 2 LEDs load with VF = 3.8V in series, Rext = Parameter. . . . 12Figure 3-5 Supply Current versus VS IS = f(VS), 2 LEDs load with VF = 3.8V in series. . . . . . . . . . . . . . . . . . . 12Figure 3-6 Output Current versus Rext Iout = f(Rext), VS = 10 V, Vout = 7.6 V . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Figure 3-7 Output Current versus Vdrop Iout = f(Vdrop), VS = 10 V, Vout = 7.6 V. . . . . . . . . . . . . . . . . . . . . . . . . . 13Figure 4-1 Application Circuit: Stand alone current source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14Figure 4-2 Application Circuit: Supply voltages > 18 V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14Figure 5-1 Package Outline for SOT343 (dimensions in mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Figure 5-2 Package Footprint for SOT343 (dimensions in mm). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Figure 5-3 Tape and Reel Information for SOT343 (dimensions in mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

List of Figures

BCR401W

List of Tables



List of Tables

BCR401W

LED Driver


1 LED Driver

1.1 Features


1.3 General DescriptionThe BCR401W is a cost efficient LED driver to drive low power LEDs. The advantages towards resistor biasingare:• homogenous light output despite of varying forward voltages in different LED strings• homogenous light output of LEDs despite of voltage drop across long supply lines• homogenous light output independent from supply voltage variations• longer lifetime of the LEDs due to reduced output current at higher temperatures (negative thermal coefficient)The advantages towards discrete solutions are:• lower assembly cost• smaller form factor• higher reliability due to less soldering joints• higher output current accuracy due to pretested LED driversDimming is possible by using an external digital transistor at the ground pin.The BCR401W can be operated at higher supply voltages adding LEDs between the supply voltage VS and thepower supply pin of the LED driver. You can find further details in our application notes.

• LED drive current preset to 10 mA• Output current adjustable up to 60 mA with an external resistor• Easy paralleling of drivers to increase current• Supply voltage up to 18 V• High current accuracy at supply voltage variation• Low voltage overhead of 1.2 V• Up to 500 mW power dissipation in a small SOT343 package• Negative thermal coefficient of -0.3 %/K reduces output current at higher temperatures• RoHS compliant (Pb-free) package• Automotive qualified according AEC Q101

SOT343-3D

BCR401W

LED Driver


The BCR401W is a perfect fit for numerous low power LED applications by combining small form factor with lowcost. These LED drivers offer several advantages to resistors like significantly higher current control at very lowvoltage drop ensuring high lifetime of the LEDs.


Type Marking Pin Configuration PackageBCR401W W5s 1 = GND 2 = IOUT 3 = VS 4 = Rext SOT343


GND

IOUT VS

Rext1

23

4

GND IOUT

+VS

Vdrop

21

IoutIS

Rext

VS

4

3

Rext

(optional )

BCR401W






Min. Typ. Max.Supply voltage VS - - 18 VOutput current Iout - - 60 mAOutput voltage Vout - - 18 VReverse voltage between all terminals VR - - 0.5 VTotal power dissipation Ptot - - 500 mW TS ≤ 95 °CJunction temperature TJ - - 150 °CStorage temperature range TSTG -65 - 150 °C





Min. Typ. Max.Collector-emitter breakdown voltage VBR(CEO) 18 - - V IC = 100 µA, IB = 0Supply current IS 350 440 540 µA VS = 10 VDC current gain hFE - 150 - - IC = 50 mA, VCE = 1 VInternal resistor Rint 68 79 90 Ω IRint = 10 mAOutput current Iout 9 10 11 mA VS = 10 V

Vout = 7.6 VVoltage drop (VRext) Vdrop - 0.79 - V Iout = 10 mA



BCR401W






0

100

200

300

400

500

600

0 20 40 60 80 100 120 140

Pto

t [m

W]

TS [°C]

1

10

100

10-6

10-5

10-4

10-3

10-2

10-1

100

Rth

JS [

K/W

]

tp [s]

D = 0D = 0.005D = 0.01D = 0.02D = 0.05D = 0.1D = 0.2D = 0.5

BCR401W




1

10

100

10-6

10-5

10-4

10-3

10-2

10-1

100

Pto

tma

x /

Pto

tDC

tp [s]

D = 0D = 0.005D = 0.01D = 0.02D = 0.05D = 0.1D = 0.2D = 0.5

BCR401W



Figure 3-4 Output Current versus VS Iout = f(VS), 2 LEDs load with VF = 3.8V in series, Rext = Parameter

Figure 3-5 Supply Current versus VS IS = f(VS), 2 LEDs load with VF = 3.8V in series

1

10

100

0 2 4 6 8 10 12 14 16 18

Io

ut [m

A]

VS [V]

Rext = openRext = 160 ΩRext = 82 ΩRext = 36 Ω

10-5

10-4

10-3

0 2 4 6 8 10 12 14 16 18

IS [

A]

VS [V]

BCR401W



Figure 3-6 Output Current versus Rext Iout = f(Rext), VS = 10 V, Vout = 7.6 V

Figure 3-7 Output Current versus Vdrop Iout = f(Vdrop), VS = 10 V, Vout = 7.6 V

0

10

20

30

40

50

60

10 100 1000

Io

ut [m

A]

Rext [Ω]

10-5

10-4

10-3

10-2

10-1

0.6 0.65 0.7 0.75 0.8 0.85 0.9 0.95 1

Io

ut [A

]

Vdrop [V]

BCR401W

Application hints


4 Application hints


Figure 4-2 Application Circuit: Supply voltages > 18 V

Application hintsBCR401W serves as an easy to use constant current source for LEDs. In stand alone application an externalresistor Rext can be connected to adjust the current between 10 mA and 60 mA. Rext can be determined by usingFigure 3-6. Connecting a low tolerance resistor Rext will improve the overall accuracy of the current senseresistance formed by the parallel connection of Rint and Rext leading to an improved current accuracy. Please takeinto account that the resulting output currents will be slightly lower due to the self heating of the component andthe negative thermal coefficient.Please visit our web site www.infineon.com/lowcostleddriver for detailed application notes.

GND Iout

+VS

Vdrop

21

IoutIS

Rext

VS

4

3

Rext

(optional )

GND Iout

+VS

Vdrop

21

IS + Iout

IS

Rext

VS

4

3

Rext(optional )

Iout


BCR401W

Package


5 Package

Figure 5-1 Package Outline for SOT343 (dimensions in mm)

Figure 5-2 Package Footprint for SOT343 (dimensions in mm)

Figure 5-3 Tape and Reel Information for SOT343 (dimensions in mm)

SOT343-PO V08

1.25

±0.1

0.1 MAX.

2.1±

0.1

0.15 +0.1-0.050.3 +0.1

2 ±0.2±0.10.9

3

2

4

1

A

+0.10.6AM0.2

1.3

-0.05

-0.05

0.15

0.1 M

4x

0.1

0.1

MIN

.0.6

SOT343-FP V08

0.8

1.6

1.15

0.9

SOT323-TP V02

0.24

2.15

8

2.3

1.1Pin 1

BCR401W

Terminology


Terminology







BCR402U

LED Driver






BCR402U




Revision HistoryPage or Item Subjects (major changes since previous revision)Revision 2.0, 2012-04-13All Datasheet layout updatedTable 2-1 Vout limit increasedTable 2-3 Rint limits tightenedFigure 3-7 Temperature labels updatedFigure 3-8 Temperature labels updated

BCR402U

Table of Contents



List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6





5 Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Table of Contents

BCR402U

List of Figures


Figure 1-1 Pin configuration and typical application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Figure 3-1 Total Power Dissipation Ptot = f(TS). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Figure 3-2 Permissible Pulse Load RthJS = f(tp) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Figure 3-3 Permissible Pulse Load Ptotmax / PtotDC= f(tp) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Figure 3-4 Output Current versus VS Iout = f(VS), VS - Vout = 1.4 V, Rext = Parameter. . . . . . . . . . . . . . . . . . . . 12Figure 3-5 Supply Current versus VS IS = f(VS), TA = Parameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Figure 3-6 Output Current versus VS Iout = f(VS), VS - Vout = Parameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Figure 3-7 Output Current versus VS Iout = f(VS), VS - Vout = 1.4 V, TA = Parameter. . . . . . . . . . . . . . . . . . . . . 13Figure 3-8 Output Current versus Rext Iout = f(Rext), VS = 10 V, VS - Vout = 1.4 V, TA = Parameter . . . . . . . . . . 14Figure 3-9 Output Current versus TS Iout = f(TS), VS = 10 V, VS - Vout = 1.4 V, Rext = Parameter . . . . . . . . . . . 14Figure 3-10 Reference Voltage Vdrop vs Iout Vdrop = f(Iout), Iout = 10 µA to 10 mA . . . . . . . . . . . . . . . . . . . . . . . . 15Figure 3-11 Reference Voltage Vdrop vs Iout Vdrop = f(Iout), Iout = 10 mA to 65 mA . . . . . . . . . . . . . . . . . . . . . . . . 15Figure 4-1 Application Circuit: Stand alone current source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16Figure 4-2 Application Circuit: Boost mode current source with external power transistor . . . . . . . . . . . . . . . 16Figure 5-1 Package Outline for SC74 (dimensions in mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Figure 5-2 Package Footprint for SC74 (dimensions in mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Figure 5-3 Tape and Reel Information for SC74 (dimensions in mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

List of Figures

BCR402U

List of Tables



List of Tables

BCR402U

LED Driver


1 LED Driver

1.1 Features


1.3 General DescriptionThe BCR402U is a cost efficient LED driver to drive low power LEDs. The advantages towards resistor biasing are:• homogenous light output despite varying forward voltages in different LED strings• homogenous light output of LEDs despite voltage drop across long supply lines• homogenous light output independent from supply voltage variations• longer lifetime of the LEDs due to reduced output current at higher temperatures (negative thermal coefficient)The advantages towards discrete solutions are:• lower assembly cost• smaller form factor• higher reliability due to less soldering joints• higher output current accuracy due to pretested LED driversDimming is possible by using an external digital transistor at the ground pin.The BCR402U can be operated at higher supply voltages by putting LEDs between the supply voltage VS and thepower supply pin of the LED driver. You can find further details in our application notes.The BCR402U is a perfect fit for numerous low power LED applications by combining small form factor with lowcost. These LED drivers offer several advantages to resistors like significantly higher current control at very lowvoltage drop ensuring high lifetime of LEDs.

• LED drive current preset to 20 mA• Output current adjustable up to 65 mA with an external resistor• Easy paralleling of drivers to increase current• Supply voltage up to 40 V• High current accuracy at supply voltage variation• Low voltage overhead of 1.4 V• Up to 750 mW power dissipation in a small SC74 package• Negative thermal coefficient of -0.2 %/K reduces output current at higher temperatures• RoHS compliant (Pb-free) package• Automotive qualified according AEC Q101

SC74-3D

BCR402U

LED Driver



Type Marking Pin Configuration PackageBCR402U L2s 1 = GND 2; 3; 5 = OUT 4 = VS 6 = Rext SC74


GND

OUT

OUT VS

OUT

Rext1

2

3 4

5

6

GND OUT

+VS

Vdrop

2,3,51

IoutIS

Rext

VS

6

4

Rext

(optional )

BCR402U






Min. Typ. Max.Supply voltage VS - - 40 VOutput current Iout - - 65 mAOutput voltage Vout - - 40 VReverse voltage between all terminals VR - - 0.5 VTotal power dissipation Ptot - - 750 mW TS ≤ 112.5 °CJunction temperature TJ - - 150 °CStorage temperature range TSTG -65 - 150 °C





Min. Typ. Max.Collector-emitter breakdown voltage VBR(CEO) 40 - - V IC = 1 mA, IB = 0Supply current IS 340 420 500 µA VS = 10 VDC current gain hFE 100 220 470 - IC = 50 mA, VCE = 1 VInternal resistor Rint 38 44 52 Ω IRint = 10 mAOutput current Iout 18 20 22 mA VS = 10 V

Vout = 8.6 VVoltage drop (VRext) Vdrop 0.8 0.85 0.9 V Iout = 20 mA



BCR402U






0

200

400

600

800

1000

0 20 40 60 80 100 120 140

Pto

t [m

W]

TS [°C]

0.1

1

10

100

10-6

10-5

10-4

10-3

10-2

10-1

100

Rth

JS [

K/W

]

tp [s]

D = 0D = 0.005D = 0.01D = 0.02D = 0.05D = 0.1D = 0.2D = 0.5

BCR402U




1

10

100

1000

10-6

10-5

10-4

10-3

10-2

10-1

100

Pto

tma

x /

Pto

tDC

tp [s]

D = 0D = 0.005D = 0.01D = 0.02D = 0.05D = 0.1D = 0.2D = 0.5

BCR402U



Figure 3-4 Output Current versus VS Iout = f(VS), VS - Vout = 1.4 V, Rext = Parameter

Figure 3-5 Supply Current versus VS IS = f(VS), TA = Parameter

1

10

100

0 5 10 15 20 25

Io

ut [m

A]

VS [V]

Rext = openRext = 75 ΩRext = 24 Ω

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

0 5 10 15 20 25 30 35 40

IS [

mA

]

VS [V]

80 °C20 °C

-40 °C

BCR402U



Figure 3-6 Output Current versus VS Iout = f(VS), VS - Vout = Parameter

Figure 3-7 Output Current versus VS Iout = f(VS), VS - Vout = 1.4 V, TA = Parameter

10

15

20

25

0 5 10 15 20 25 30 35 40

Io

ut [m

A]

VS [V]

1 V1.4 - 2 V

0

5

10

15

20

25

0 5 10 15 20 25 30 35 40

Io

ut [m

A]

VS [V]

-40 °C20 °C80 °C

BCR402U



Figure 3-8 Output Current versus Rext Iout = f(Rext), VS = 10 V, VS - Vout = 1.4 V, TA = Parameter

Figure 3-9 Output Current versus TS Iout = f(TS), VS = 10 V, VS - Vout = 1.4 V, Rext = Parameter

10

100

10 100

Io

ut [m

A]

Rext [Ω]

-40 °C20 °C80 °C

0

10

20

30

40

50

60

70

-50 -25 0 25 50 75 100 125 150

Io

ut [m

A]

TS [°C]

Rext = open

Rext = 120Ω

Rext = 56 Ω

Rext = 33 Ω

Rext = 27 Ω

Rext = 18 Ω

BCR402U



Figure 3-10 Reference Voltage Vdrop vs Iout Vdrop = f(Iout), Iout = 10 µA to 10 mA

Figure 3-11 Reference Voltage Vdrop vs Iout Vdrop = f(Iout), Iout = 10 mA to 65 mA

0.8

0.85

0.9

0.95

1

1.05

1.1

10-5

10-4

10-3

10-2

Vd

rop [

V]

IOUT [A]

typ.min., max.

0.6

0.65

0.7

0.75

0.8

0.85

0.9

0.95

1

10 20 30 40 50 60 70

Vd

rop [

V]

IOUT [mA]

typ.min., max.

BCR402U

Application hints


4 Application hints


Figure 4-2 Application Circuit: Boost mode current source with external power transistor

Application hintsBCR402U serves as an easy to use constant current source for LEDs. In stand alone application an externalresistor Rext can be connected to adjust the current between 20 mA and 65 mA. Rext can be determined by usingFigure 3-8. Connecting a low tolerance resistor Rext will improve the overall accuracy of the current senseresistance formed by the parallel connection of Rint and Rext leading to an improved current accuracy. Please takeinto account that the resulting output currents will be slightly lower due to the self heating of the component andthe negative thermal coefficient.In boost mode configuration the LED current can be extended to drive high power LEDs. Please visit our web sitewww.infineon.com/lowcostleddriver for detailed application notes.

GND OUT

+VS

Vdrop

2,3,51

IoutIS

Rext

VS

6

4

Rext

(optional )

GND OUT

+VS

Vdrop

2,3,51

Iout

IS

Rext

VS

6

4

ILED

R1

R2

Rext

(optional )


BCR402U

Package


5 Package




SC74-PO V04

5 46

321

1.1 MAX.

(0.35)

(2.25)±0.22.9

B

0.2+0.1-0.050.35

Pin 1marking

M B 6x0.95

1.9

0.15 -0.06+0.1

1.6

A

±0.1

2.5

0.25

±0.1

±0.1

A0.2 M

0.1 MAX.

0.5

0.95

1.9

2.9

SC74-FPR V04

SC74-TP

2.7

4

3.15Pin 1marking

8

0.2

1.15

BCR402U

Terminology


Terminology

∆Iout/Iout Output current changehFE DC current gainIEN Enable currentILED LED currentIout Output currentIR Reverse currentLED Light Emitting DiodePCB Printed Circuit BoardPtot Total power dissipationPWM Pulse Width ModulationRB Bias resistorRext External resistorRint Internal resistorRoHs Restriction of Hazardous Substance directiveRthJS Thermal resistance junction to soldering pointTA Ambient temperatureTJ Junction temperatureTS Soldering point temperatureTstg Storage temperatureVBR(CEO) Collector-emitter breakdown voltageVBR Breakdown voltageVdrop Voltage dropVEN Enable voltageVout Output voltageVR Reverse voltageVS Supply voltageVSmin Lowest sufficient supply voltage overhead






BCR402W

LED Driver






BCR402W





BCR402W

Table of Contents



List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6





5 Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Table of Contents

BCR402W

List of Figures


Figure 1-1 Pin configuration and typical application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Figure 3-1 Total Power Dissipation Ptot = f(TS). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Figure 3-2 Permissible Pulse Load RthJS = f(tp) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Figure 3-3 Permissible Pulse Load Ptotmax / PtotDC= f(tp) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Figure 3-4 Output Current versus VS Iout = f(VS), 2 LEDs load with VF = 3.8V in series, Rext = Parameter. . . . 12Figure 3-5 Supply Current versus VS IS = f(VS), 2 LEDs load with VF = 3.8V in series. . . . . . . . . . . . . . . . . . . 12Figure 3-6 Output Current versus Rext Iout = f(Rext), VS = 10 V, Vout = 7.6 V . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Figure 3-7 Output Current versus Vdrop Iout = f(Vdrop), VS = 10 V, Vout = 7.6 V. . . . . . . . . . . . . . . . . . . . . . . . . . 13Figure 4-1 Application Circuit: Stand alone current source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14Figure 4-2 Application Circuit: Supply voltages > 18 V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14Figure 5-1 Package Outline for SOT343 (dimensions in mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Figure 5-2 Package Footprint for SOT343 (dimensions in mm). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Figure 5-3 Tape and Reel Information for SOT343 (dimensions in mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

List of Figures

BCR402W

List of Tables



List of Tables

BCR402W

LED Driver


1 LED Driver

1.1 Features


1.3 General DescriptionThe BCR402W is a cost efficient LED driver to drive low power LEDs. The advantages towards resistor biasingare:• homogenous light output despite of varying forward voltages in different LED strings• homogenous light output of LEDs despite of voltage drop across long supply lines• homogenous light output independent from supply voltage variations• longer lifetime of the LEDs due to reduced output current at higher temperatures (negative thermal coefficient)The advantages towards discrete solutions are:• lower assembly cost• smaller form factor• higher reliability due to less soldering joints• higher output current accuracy due to pretested LED driversDimming is possible by using an external digital transistor at the ground pin.The BCR402W can be operated at higher supply voltages adding LEDs between the supply voltage VS and thepower supply pin of the LED driver. You can find further details in our application notes.

• LED drive current preset to 20 mA• Output current adjustable up to 60 mA with an external resistor• Easy paralleling of drivers to increase current• Supply voltage up to 18 V• High current accuracy at supply voltage variation• Low voltage overhead of 1.2 V• Up to 500 mW power dissipation in a small SOT343 package• Negative thermal coefficient of -0.3 %/K reduces output current at higher temperatures• RoHS compliant (Pb-free) package• Automotive qualified according AEC Q101

SOT343-3D

BCR402W

LED Driver


The BCR402W is a perfect fit for numerous low power LED applications by combining small form factor with lowcost. These LED drivers offer several advantages to resistors like significantly higher current control at very lowvoltage drop ensuring high lifetime of the LEDs.


Type Marking Pin Configuration PackageBCR402W W6s 1 = GND 2 = IOUT 3 = VS 4 = Rext SOT343


GND

IOUT VS

Rext1

23

4

GND IOUT

+VS

Vdrop

21

IoutIS

Rext

VS

4

3

Rext

(optional )

BCR402W






Min. Typ. Max.Supply voltage VS - - 18 VOutput current Iout - - 60 mAOutput voltage Vout - - 18 VReverse voltage between all terminals VR - - 0.5 VTotal power dissipation Ptot - - 500 mW TS ≤ 95 °CJunction temperature TJ - - 150 °CStorage temperature range TSTG -65 - 150 °C





Min. Typ. Max.Collector-emitter breakdown voltage VBR(CEO) 18 - - V IC = 100 µA, IB = 0Supply current IS 350 440 540 µA VS = 10 VDC current gain hFE - 150 - - IC = 50 mA, VCE = 1 VInternal resistor Rint 33 38 45 Ω IRint = 10 mAOutput current Iout 18 20 22 mA VS = 10 V

Vout = 7.6 VVoltage drop (VRext) Vdrop - 0.76 - V Iout = 20 mA



BCR402W






0

100

200

300

400

500

600

0 20 40 60 80 100 120 140

Pto

t [m

W]

TS [°C]

1

10

100

10-6

10-5

10-4

10-3

10-2

10-1

100

Rth

JS [

K/W

]

tp [s]

D = 0D = 0.005D = 0.01D = 0.02D = 0.05D = 0.1D = 0.2D = 0.5

BCR402W




1

10

100

10-6

10-5

10-4

10-3

10-2

10-1

100

Pto

tma

x /

Pto

tDC

tp [s]

D = 0D = 0.005D = 0.01D = 0.02D = 0.05D = 0.1D = 0.2D = 0.5

BCR402W



Figure 3-4 Output Current versus VS Iout = f(VS), 2 LEDs load with VF = 3.8V in series, Rext = Parameter

Figure 3-5 Supply Current versus VS IS = f(VS), 2 LEDs load with VF = 3.8V in series

1

10

100

0 2 4 6 8 10 12 14 16 18

Io

ut [m

A]

VS [V]

Rext = openRext = 68 Ω

10-5

10-4

10-3

0 2 4 6 8 10 12 14 16 18

IS [

A]

VS [V]

BCR402W



Figure 3-6 Output Current versus Rext Iout = f(Rext), VS = 10 V, Vout = 7.6 V

Figure 3-7 Output Current versus Vdrop Iout = f(Vdrop), VS = 10 V, Vout = 7.6 V

0

10

20

30

40

50

60

10 100 1000

Io

ut [m

A]

Rext [Ω]

10-5

10-4

10-3

10-2

10-1

0.6 0.65 0.7 0.75 0.8 0.85 0.9 0.95 1

Io

ut [A

]

Vdrop [V]

BCR402W

Application hints


4 Application hints


Figure 4-2 Application Circuit: Supply voltages > 18 V

Application hintsBCR402W serves as an easy to use constant current source for LEDs. In stand alone application an externalresistor Rext can be connected to adjust the current between 20 mA and 60 mA. Rext can be determined by usingFigure 3-6. Connecting a low tolerance resistor Rext will improve the overall accuracy of the current senseresistance formed by the parallel connection of Rint and Rext leading to an improved current accuracy. Please takeinto account that the resulting output currents will be slightly lower due to the self heating of the component andthe negative thermal coefficient.Please visit our web site www.infineon.com/lowcostleddriver for detailed application notes.

GND Iout

+VS

Vdrop

21

IoutIS

Rext

VS

4

3

Rext

(optional )

GND Iout

+VS

Vdrop

21

IS + Iout

IS

Rext

VS

4

3

Rext(optional )

Iout


BCR402W

Package


5 Package

Figure 5-1 Package Outline for SOT343 (dimensions in mm)

Figure 5-2 Package Footprint for SOT343 (dimensions in mm)

Figure 5-3 Tape and Reel Information for SOT343 (dimensions in mm)

SOT343-PO V08

1.25

±0.1

0.1 MAX.

2.1±

0.1

0.15 +0.1-0.050.3 +0.1

2 ±0.2±0.10.9

3

2

4

1

A

+0.10.6AM0.2

1.3

-0.05

-0.05

0.15

0.1 M

4x

0.1

0.1

MIN

.0.6

SOT343-FP V08

0.8

1.6

1.15

0.9

SOT323-TP V02

0.24

2.15

8

2.3

1.1Pin 1

BCR402W

Terminology


Terminology







BCR420U / BCR421U

LED Driver






BCR420U / BCR421U




Revision HistoryPage or Item Subjects (major changes since previous revision)Revision 2.0, 2012-05-04All Datasheet layout updatedTable 2-1 Vout limit increasedTable 2-3 Rint limits tightenedTable 2-3 Iout limits tightenedFigure 3-13 Figure updatedFigure 3-22 8 Ω label updated

BCR420U / BCR421U

Table of Contents



List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6





5 Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Table of Contents

BCR420U / BCR421U

List of Figures


Figure 1-1 Pin configuration and typical application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Figure 3-1 Total Power Dissipation Ptot = f(TS). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Figure 3-2 Permissible Pulse Load RthJS = f(tp) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Figure 3-3 Permissible Pulse Load Ptotmax / PtotDC= f(tp) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Figure 3-4 BCR420U: Output Current versus Vout Iout = f(Vout), VEN = 40 V, Rext = Parameter . . . . . . . . . . . . . 13Figure 3-5 BCR420U: Output Current versus Rext Iout = f(Rext), VEN = 40 V, Vout = Parameter . . . . . . . . . . . . . 13Figure 3-6 BCR420U: Output Current versus Vout Iout = f(Vout), VEN = 40 V, Rext = open, TA = Parameter . . . . 14Figure 3-7 BCR420U: Output Current versus Vout Iout = f(Vout), VEN = 40 V, Rext = 20 Ω, TA = Parameter . . . . 14Figure 3-8 BCR420U: Output Current versus Vout Iout = f(Vout), VEN = 40 V, Rext = 6 Ω, TA = Parameter . . . . . 15Figure 3-9 BCR420U: Output Current versus VEN Iout = f(VEN), Vout = 2 V, Rext = open, TA = Parameter . . . . . 15Figure 3-10 BCR420U: Output Current versus VEN Iout = f(VEN), Vout = 2 V, Rext = 20 Ω, TA = Parameter . . . . . 16Figure 3-11 BCR420U: Output Current versus VEN Iout = f(VEN), Vout = 2 V, Rext = 6 Ω, TA = Parameter . . . . . . 16Figure 3-12 BCR420U: Output Current versus VEN Iout = f(VEN), Vout = 2 V, Rext = Parameter . . . . . . . . . . . . . . 17Figure 3-13 BCR420U: Enable Current versus VEN IEN = f(VEN), Rext = open, Iout = 0 A, TA = Parameter . . . . . 17Figure 3-14 BCR421U: Output Current versus Vout Iout = f(Vout), VEN = 3.3 V, Rext = Parameter . . . . . . . . . . . . 18Figure 3-15 BCR421U: Output Current versus Rext Iout = f(Rext), VEN = 3.3 V, Vout = Parameter . . . . . . . . . . . . 18Figure 3-16 BCR421U: Output Current versus Vout Iout = f(Vout), VEN = 3.3 V, Rext = open, TA = Parameter . . . 19Figure 3-17 BCR421U: Output Current versus Vout Iout = f(Vout), VEN = 3.3 V, Rext = 20 Ω, TA = Parameter. . . . 19Figure 3-18 BCR421U: Output Current versus Vout Iout = f(Vout), VEN = 3.3 V, Rext = 6 Ω, TA = Parameter. . . . . 20Figure 3-19 BCR421U: Output Current versus VEN Iout = f(VEN), Vout = 2 V, Rext = open, TA = Parameter . . . . . 20Figure 3-20 BCR421U: Output Current versus VEN Iout = f(VEN), Vout = 2 V, Rext = 20 Ω, TA = Parameter . . . . . 21Figure 3-21 BCR421U: Output Current versus VEN Iout = f(VEN), Vout = 2 V, Rext = 6 Ω, TA = Parameter . . . . . . 21Figure 3-22 BCR421U: Output Current versus VEN Iout = f(VEN), Vout = 2 V, Rext = Parameter . . . . . . . . . . . . . . 22Figure 3-23 BCR421U: Enable Current versus VEN IEN = f(VEN), Rext = open, Iout = 0 A, TA = Parameter . . . . . 22Figure 4-1 Application Circuit: Enabling / PWM by Micro Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23Figure 4-2 Application Circuit: Enabling by Connecting to VS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23Figure 5-1 Package Outline for SC74 (dimensions in mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Figure 5-2 Package Footprint for SC74 (dimensions in mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Figure 5-3 Tape and Reel Information for SC74 (dimensions in mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

List of Figures

BCR420U / BCR421U

List of Tables


Table 2-1 Maximum Ratings at TA = 25 °C, unless otherwise specified . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Table 2-2 Thermal Resistance at TA = 25 °C, unless otherwise specified. . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Table 2-3 Electrical Characteristics at TA = 25 °C, unless otherwise specified . . . . . . . . . . . . . . . . . . . . . . . . 9Table 2-4 DC Characteristics with stabilized LED load at TA = 25 °C, unless otherwise specified . . . . . . . . 10

List of Tables

BCR420U / BCR421U

LED Driver


1 LED Driver

1.1 Features

1.2 Applications• Architectural LED lighting• Channel letters for advertising, LED strips for decorative lighting• Retail lighting in fridge, freezer case and vending machines• Emergency lighting (e.g. steps lighting, exit way signs etc.)

1.3 General DescriptionThe BCR420U / BCR421U provides a low-cost solution for driving 0.25 W LEDs with a typical LED current of75 mA to 150 mA. Internal breakdown voltage is higher than 40 V which is the maximum voltage the LED drivercan sustain when the output is directly connected to supply voltage.The BCR420U / BCR421U can be operated with a supply voltage of more than 40 V considering the voltage dropof the LED load which reduces the output voltage to the maximum rating of the driver.The enable pin of BCR420U can withstand a maximum voltage of 40 V which can be increased adding a seriesresistor in front of the enable pin reducing the voltage at the enable pin below 40 V.The digital input pin of BCR421U allows dimming via a micro controller with frequencies up to 10 kHz.A reduction of the output current at higher temperatures is the result of the negative temperature coefficient of -0.2 %/K of the LED driver.With no need for additional external components like inductors, capacitors and free wheeling diodes, theBCR420U / BCR421U LED drivers are a cost-efficient and PCB-area saving solution for driving 0.25 W LEDs.

• LED drive current preset to 10 mA• Continuous output current up to 150 mA with an external resistor• Easy paralleling of drivers to increase current• Supply voltage up to 40 V• Low side current control• Digital PWM input up to 10 kHz frequency (BCR421U)• Up to 1 W power dissipation in a small SC74 package• Negative thermal coefficient of -0.2 %/K reduces output current at higher temperatures• RoHS compliant (Pb-free) package• Automotive qualified according AEC Q101

SC74-3D

BCR420U / BCR421U

LED Driver



Type Marking Pin Configuration PackageBCR420U 40 1 = EN 2; 3; 5 = OUT 4 = GND 6 = Rext SC74BCR421U 41 1 = EN 2; 3; 5 = OUT 4 = GND 6 = Rext SC74


EN OUT

Rext

GND

+VS

Vdrop

2,3,51

6

4

IoutIEN

BCR420 U

EN

OUT

OUT GND

OUT

Rext1

2

3 4

5

6

Rext(optional )

BCR420U / BCR421U






Min. Typ. Max.Enable voltageBCR420UBCR421U

VEN--

--

404.5

V

Output current Iout - - 200 mAOutput voltage Vout - - 40 VReverse voltage between all terminals VR - - 0.5 VTotal power dissipation Ptot - - 1000 mW TS ≤ 100 °CJunction temperature TJ - - 150 °CStorage temperature range TSTG -65 - 150 °C





Min. Typ. Max.Collector-emitter breakdown voltage VBR(CEO) 40 - - V IC = 1 mA, IB = 0Enable currentBCR420UBCR421U

IEN--

1.2 1.2

--

mAVEN = 24 VVEN = 3.3 V

DC current gain hFE 200 350 500 - IC = 50 mA, VCE = 1 VInternal resistor Rint 85 95 105 Ω IRint = 10 mABias resistorBCR420UBCR421U

RB--

201.5

--

kΩ

BCR420U / BCR421U



Output currentBCR420UBCR421UOutput current at Rext = 5.1 ΩBCR420UBCR421U

Iout9 9

--

10 10

150 150

1111

--

mA Vout = 1.4 VVEN = 24 VVEN = 3.3 VVout > 2.0 VVEN = 24 VVEN = 3.3 V

Voltage drop (VRext) Vdrop 0.85 0.95 1.05 V Iout = 10 mA


Min. Typ. Max.Lowest sufficient supply voltage overhead VSmin - 1.4 - V Iout > 18 mAOutput current change versusTABCR420UBCR421U

∆Iout/Iout--

-0.2-0.2

--

%/K Vout > 2.0 VVEN = 24 VVEN = 3.3 V

Output current change versus VSBCR420UBCR421U

∆Iout/Iout--

11

--

%/V Vout > 2.0 VVEN = 24 VVEN = 3.3 V

Table 2-3 Electrical Characteristics at TA = 25 °C, unless otherwise specified (cont’d)

Parameter Symbol Values Unit Note / Test ConditionMin. Typ. Max.

BCR420U / BCR421U






0

200

400

600

800

1000

1200

0 20 40 60 80 100 120 140

Pto

t [m

W]

TS [°C]

0.1

1

10

100

10-6

10-5

10-4

10-3

10-2

10-1

100

Rth

JS [

K/W

]

tp [s]

D = 0D = 0.005D = 0.01D = 0.02D = 0.05D = 0.1D = 0.2D = 0.5

BCR420U / BCR421U




1

10

100

1000

10-6

10-5

10-4

10-3

10-2

10-1

100

Pto

tma

x /

Pto

tDC

tp [s]

D = 0D = 0.005D = 0.01D = 0.02D = 0.05D = 0.1D = 0.2D = 0.5

BCR420U / BCR421U



Figure 3-4 BCR420U: Output Current versus Vout Iout = f(Vout), VEN = 40 V, Rext = Parameter

Figure 3-5 BCR420U: Output Current versus Rext Iout = f(Rext), VEN = 40 V, Vout = Parameter

0

0.05

0.1

0.15

0.2

0 1 2 3 4 5 6 7 8 9 10 11 12

Io

ut [A

]

Vout [V]

Rext = open

Rext = 30 Ω

Rext = 15 Ω

Rext = 10 Ω

Rext = 8 Ω

Rext = 6 Ω

0

0.05

0.1

0.15

0.2

1 10 100

Io

ut [A

]

Rext [Ω]


BCR420U / BCR421U



Figure 3-6 BCR420U: Output Current versus Vout Iout = f(Vout), VEN = 40 V, Rext = open, TA = Parameter


0

0.005

0.01

0.015

0 2 4 6 8 10 12

Io

ut [A

]

Vout [V]

-40 °C25 °C85 °C

0

0.01

0.02

0.03

0.04

0.05

0.06

0 2 4 6 8 10 12

Io

ut [A

]

Vout [V]

-40 °C25 °C85 °C

BCR420U / BCR421U





0

0.05

0.1

0.15

0.2

0 2 4 6 8 10 12

Io

ut [A

]

Vout [V]

-40 °C25 °C85 °C

0

0.005

0.01

0.015

0 5 10 15 20 25 30

Io

ut [A

]

VEN [V]

-40 °C25 °C85 °C

BCR420U / BCR421U





0

0.01

0.02

0.03

0.04

0.05

0.06

0 5 10 15 20 25 30

Io

ut [A

]

VEN [V]

-40 °C25 °C85 °C

0

0.05

0.1

0.15

0.2

0 5 10 15 20 25 30

Io

ut [A

]

VEN [V]

-40 °C25 °C85 °C

BCR420U / BCR421U





0

0.05

0.1

0.15

0 5 10 15 20 25 30

Io

ut [A

]

VEN [V]


0

0.5

1

1.5

2

2.5

3

0 5 10 15 20 25 30 35 40

IE

N [

mA

]

VEN [V]

-40 °C25 °C80 °C

BCR420U / BCR421U



Figure 3-14 BCR421U: Output Current versus Vout Iout = f(Vout), VEN = 3.3 V, Rext = Parameter

Figure 3-15 BCR421U: Output Current versus Rext Iout = f(Rext), VEN = 3.3 V, Vout = Parameter

0

0.05

0.1

0.15

0.2

0 1 2 3 4 5 6 7 8 9 10 11 12

Io

ut [A

]

Vout [V]

Rext = open

Rext = 30 Ω

Rext = 15 Ω

Rext = 10 ΩRext = 8 Ω

Rext = 6 Ω

0

0.05

0.1

0.15

0.2

1 10 100

Io

ut [A

]

Rext [Ω]


BCR420U / BCR421U



Figure 3-16 BCR421U: Output Current versus Vout Iout = f(Vout), VEN = 3.3 V, Rext = open, TA = Parameter


0

0.005

0.01

0.015

0 2 4 6 8 10 12

Io

ut [A

]

Vout [V]

-40 °C25 °C85 °C

0

0.01

0.02

0.03

0.04

0.05

0.06

0 2 4 6 8 10 12

Io

ut [A

]

Vout [V]

-40 °C25 °C85 °C

BCR420U / BCR421U





0

0.05

0.1

0.15

0.2

0 2 4 6 8 10 12

Io

ut [A

]

Vout [V]

-40 °C25 °C85 °C

0

0.005

0.01

0.015

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

Io

ut [A

]

VEN [V]

-40 °C25 °C85 °C

BCR420U / BCR421U





0

0.01

0.02

0.03

0.04

0.05

0.06

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

Io

ut [A

]

VEN [V]

-40 °C25 °C85 °C

0

0.05

0.1

0.15

0.2

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

Io

ut [A

]

VEN [V]

-40 °C25 °C85 °C

BCR420U / BCR421U





0

0.05

0.1

0.15

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

Io

ut [A

]

VEN [V]


0

0.5

1

1.5

2

2.5

3

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

IE

N [

mA

]

VEN [V]

-40 °C25 °C80 °C

BCR420U / BCR421U

Application hints


4 Application hints

Figure 4-1 Application Circuit: Enabling / PWM by Micro Controller

Figure 4-2 Application Circuit: Enabling by Connecting to VS

Application hintsBCR420U / BCR421U serve as an easy to use constant current sources for LEDs. In stand alone application anexternal resistor can be connected to adjust the current from 10 mA to 250 mA. Rext can be determined by usingFigure 3-5 or Figure 3-15. Connecting a low tolerance resistor Rext will improve the overall accuracy of the currentsense resistance formed by the parallel connection of Rint and Rext leading to an improved current accuracy. Pleasetake into account that the resulting output currents will be slightly lower due to the self heating of the componentand the negative thermal coefficient.Please visit our web site www.infineon.com/lowcostleddriver for application notes and for up-to-dateapplication information.

EN OUT

Rext

GND

+VS

2,3,51

IoutIEN

BCR421 U

µC

Vdrop

6

4

Rext(optional )

EN OUT

Rext

GND

+VS

Vdrop

2,3,51

6

4

IoutIEN

BCR420U

Rext(optional )


BCR420U / BCR421U

Package


5 Package




SC74-PO V04

5 46

321

1.1 MAX.

(0.35)

(2.25)±0.22.9

B

0.2+0.1-0.050.35

Pin 1marking

M B 6x0.95

1.9

0.15 -0.06+0.1

1.6

A

±0.1

2.5

0.25

±0.1

±0.1

A0.2 M

0.1 MAX.

0.5

0.95

1.9

2.9

SC74-FPR V04

SC74-TP

2.7

4

3.15Pin 1marking

8

0.2

1.15

BCR420U / BCR421U

Terminology


Terminology

∆Iout/Iout Output current changehFE DC current gainIEN Enable currentIout Output currentIR Reverse currentLED Light Emitting DiodePCB Printed Circuit BoardPtot Total power dissipationPWM Pulse Width ModulationRB Bias resistorRext External resistorRint Internal resistorRoHs Restriction of Hazardous Substance directiveRthJS Thermal resistance junction to soldering pointTA Ambient temperatureTJ Junction temperatureTS Soldering point temperatureTstg Storage temperatureVBR(CEO) Collector-emitter breakdown voltageVBR Breakdown voltageVdrop Voltage dropVEN Enable voltageVout Output voltageVR Reverse voltageVS Supply voltageVSmin Lowest sufficient supply voltage overhead




Documents

INFORMATION NOTEINFORMATION NOTE N 016/12 2012-05-15 Page 2 of 2 Description of change: Old datasheet edition New datasheet edition BCR401W Datasheet edition Parameter Min. Typ. Max