• Any products mentioned in this catalog are subject to any modification in their appearance and others for improvements without prior notification.• The details listed here are not a guarantee of the individual products at the time of ordering. When using the products, you will be asked to check their specifications.

MITSUMI High Voltage Operation Step-down DCDC Converter MM3370

High Voltage Operation Step-down DCDC ConverterMonolithic IC MM3370

Outline

This IC is a diode rectifier-type step-down DCDC converter IC with integrated Power MOS FET.The IC operates at a maximum output current of 3A.This is suitable for power supplies of LCTVs and DVD recorders because of its more stable load transient response (changes from 1A to 2A, approx. 50mV) and wider input voltage range (7 to 27V) .

Features

1. Soft Start Function2. Shut Down Function3. Current Limit Function4. Electrical Characteristics Operating Supply Voltage 7~27V Output Voltage 0.92V~ Reference Voltage Accuracy ±2% Maximum Output Current 3A Oscillation Frequency 500kHz Consumption Current 0.8mA (operation) 20µA (power-off)

Package

HSOP-8A

Applications

1. DVD Recorders2. Blu-ray Disc Recorders3. TVs

• Any products mentioned in this catalog are subject to any modification in their appearance and others for improvements without prior notification.• The details listed here are not a guarantee of the individual products at the time of ordering. When using the products, you will be asked to check their specifications.

MITSUMI High Voltage Operation Step-down DCDC Converter MM3370

Block Diagram

Note1CE

THERMALSHUTDOWN

INTERNALREGULATOR

OSCILLATOR500kHz

CLK

Ramp

Slope

3.7V/3.55V

9kΩ0.92V

FB SS COMP

0.7V

Err AMP

UVLO

COMP PWM COMP

VIN SupplyVoltage

5V

VIN

BS

M1120mΩ

SW

10ΩM2

GND

SW

DRH

DRL

CONTROL

to InternalCircuit

CURRENTSENSE AMP

1 2 3 4

8 7 6 5

HSOP-8ATOP VIEW

Pin Assignment

• Any products mentioned in this catalog are subject to any modification in their appearance and others for improvements without prior notification.• The details listed here are not a guarantee of the individual products at the time of ordering. When using the products, you will be asked to check their specifications.

MITSUMI High Voltage Operation Step-down DCDC Converter MM3370

Pin No. Pin name Input/Output Pin description

1 BS INPUT Boost Capacitor Connection pin

2 VIN INPUT Power Supply Voltage Input pin

3 SW OUTPUT Inductor Connection pin

4 GND INPUT Ground pin

5 FB INPUT Feedback Input pin

6 COMP OUTPUT Compensation Node pin

7 CE INPUT Chip Enable Input pin

8 SS INPUT Soft Start Control Input pin

Item Symbol Ratings UnitsStorage Temperature Tstg −55~+150 °CVIN Supply Voltage VVINMAX −0.3~+30 V

SW Pin Supply Voltage VSWMAX −1~VIN+0.3 VBS Pin Supply Voltage VBOOSTMAX VSW−0.3~VSW+6 VFB Pin Supply Voltage VFBMAX −0.3~+5.5 VCE Pin Supply Voltage VCEMAX −0.3~+30 VSS Pin Supply Voltage VSSMAX −0.3~+5.5 V

COMP Pin Supply Voltage VCOMPMAX −0.3~+5.5 VPower Dissipation Pd 2000 (Note2) mW

Item Symbol Ratings UnitsOperating Temperature TOPR −40~+85 °C

Supply Voltage VOPR +7~+27 V

BSMM3370

SW

5V

0.01uF

DIODENote3

Pin Description

Absolute Maximum Ratings (Except where noted otherwise Ta=25°C)

Note2 : JEDEC51-7 standard 120×120×1.6tmm

Recommended Operating Conditions (Except where noted otherwise Ta=25°C)

Note3 : The internal boost regulator leads to the efficiency improvement when it stabilizes and VIN is low by connecting the external boot strap diode.

• Any products mentioned in this catalog are subject to any modification in their appearance and others for improvements without prior notification.• The details listed here are not a guarantee of the individual products at the time of ordering. When using the products, you will be asked to check their specifications.

MITSUMI High Voltage Operation Step-down DCDC Converter MM3370

Item Symbol Measurement conditions Min. Typ. Max. Units

VIN Input Voltage Range VIN 7 27 V

Supply Current ISS1 VCE=3V, VFB=1.4V 0.8 1.2 mA

Shutdown Supply Current ISS2 VCE=0V 20 40 μA

Feedback Voltage VFB 7V VIN 27V 0.90 0.92 0.94 V

Maximum Output Current IOMAX 3.0 A

Error Amplifier Transconductance GEA ICOMP=±10μA 800 μA/V

High-Side Switch On-Resistance (Note4) RONH 120 m

Low-Side Switch On-Resistance RONL 10

High-Side Switch Leakage Current ILEAK VCE=0V, VSW=0V 0.1 10 μA

Short Circuit Current Limit (Note4) ILIM 8 A

Oscillation Frequency fSW 400 500 600 kHz

Maximum Duty Cycle DMAX VFB=0.8V 88 %

Minimum ON Time (Note4) TON 120 ns

CE Pin Threshold Voltage VCET 1.1 1.4 1.7 V

UVLO Detection Voltage(Note5) VUVLO VIN Rising 3.4 3.7 4.0 V

UVLO Hysteresis Voltage VUVLO 150 mV

Thermal Shutdown (Note4) THD 160 °C

Electrical Characteristics (Except where noted otherwise VIN=12V, Ta=25°C)

Note4 : Guaranteed by design.Note5 : When VIN is from UVLO detection voltage 3.7V(TYP.) to VIN input voltage 7V(MIN.) , the switching output operates intermittent and the output.

• Any products mentioned in this catalog are subject to any modification in their appearance and others for improvements without prior notification.• The details listed here are not a guarantee of the individual products at the time of ordering. When using the products, you will be asked to check their specifications.

MITSUMI High Voltage Operation Step-down DCDC Converter MM3370

Test CircuitTest Circuit 1

Test Circuit 2

Test Circuit 3

VIN BS

SWCE

FBCOMPGND

SS

V A

A

C4

VIN C1

2

7

8

4 6

1

5

3

C5 Oscillosope

VIN

VIN

BS2

7

8

4 6

SWCE

FBCOMPGND

SSC1

C4

Oscilloscope

Vout

R1

R2

R3

SBD

C2

LC5

C3

3

1

5

V

VIN

VIN

BS

SWCE

FB

COMPGND

SSC1

C4A

2

7

8

4 6

3

1

5

• Any products mentioned in this catalog are subject to any modification in their appearance and others for improvements without prior notification.• The details listed here are not a guarantee of the individual products at the time of ordering. When using the products, you will be asked to check their specifications.

MITSUMI High Voltage Operation Step-down DCDC Converter MM3370

MM3370 is step-down converter with built-in MOSFET of the low on resistance in single-chip.It is able to supply up to 3A of load current within the wide range from 7V in the input voltage to 27V. To operate by the current mode control, the simplification of the phase amends, the improvement of the load response characteristic, and the improvement of the line regulation characteristic have been achieved. The output voltage is input to the FB PIN through the connected resistance, and amplified through the internal error amplifier. It is output to the COMP PIN in the error amplifier compared with an internal standard voltage (= SS PIN) and Duty is controlled.

Description

· INTERNAL REGURATOR Constant voltage generation block for internal circuit.

· THERMAL SHUTDOWN Over Temperature Protection block. When the temperature of the chip exceeds 160°C (TYP.), it is set that it shuts down.

· Err AMP Error Amplifier.It is a circuit that compares reference voltage with the feedback voltage. Because the COMP PIN that outputs the result of compare it with the SS PIN where reference voltage hangs is output as a terminal, external parts can be connected.

· OSCILLATOR Oscillator. It is a circuit that generates the switching frequency.

· Slope-COMP It is a circuit that adds the amount of the current of MOSFET detected in the triangular wave generated with the oscillator with a current sense amplifier. The added shape of waves is output to PWMCOMP.

· CURRENT SENSE AMP It adds to the triangular wave generated with the oscillator by detecting the current on high side MOSFET, and converting the voltage.

· PWM COMP The ErrAMP output is compared with the Slope-COMP output and Duty of the switching is decided.

Operation Explanation

Device Operation

• Any products mentioned in this catalog are subject to any modification in their appearance and others for improvements without prior notification.• The details listed here are not a guarantee of the individual products at the time of ordering. When using the products, you will be asked to check their specifications.

MITSUMI High Voltage Operation Step-down DCDC Converter MM3370

Timing Chart(1) Start Up

(2) Over Current Detection

* The values indicate representative values.

VIN

CE

SW

VOUT

ov

ov

ov

H

L

Soft Start Time Soft Start Time

Tss Tss Tss(Note4)

Note6: Tss(ms)=45xC4(uF)

3.7V 150mV

VunoVuno

Soft Start Time

VIN

ov

ov

ov

0A

H

LCE

SW

VFB

IOUT

T

Soft Start Time Over Current

fs=500kHz

Output Short

8ACurrent Limit Current Limitss

• Any products mentioned in this catalog are subject to any modification in their appearance and others for improvements without prior notification.• The details listed here are not a guarantee of the individual products at the time of ordering. When using the products, you will be asked to check their specifications.

MITSUMI High Voltage Operation Step-down DCDC Converter MM3370

Characteristics (Except where noted otherwise VIN=12V, VOUT=3.3V, L=10µH, Ta=25°C)

1009080706050403020100

0 0.5 1 1.5 2 2.5 3 3.5LOAD CURRENT(A)

EFFI

CIE

NC

Y(%

)

VIN=7V

VIN=12VVIN=27V

■ Output Current-Efficiency

VOUT

IOUT=0.5→1A

ILOAD

50mV/div.

0.5A/div.

100μ s /div

■ Load Transient Response

IL

1A/div.

VOUT

20mV/div.

VIN

VSW

500mV/div.

10V/div.

2μ s/div.

IOUT=1.5A Resistive Load

■ Steady State test

IL

2V/div.

1A/div.

VOUT

5ms/div.

IOUT=1.5A Resistive Load

■ Startup through Enable

IL

2A/div.

VOUT

20mV/div.

VIN

VSW

500mV/div

10V/div

2μs/div

IOUT=3A Resistive Load

■ Steady State test

IL

2V/div.

2A/div.

VOUT

5ms/div.

IOUT=3A Resistive Load

■ Startup through Enable

• Any products mentioned in this catalog are subject to any modification in their appearance and others for improvements without prior notification.• The details listed here are not a guarantee of the individual products at the time of ordering. When using the products, you will be asked to check their specifications.

MITSUMI High Voltage Operation Step-down DCDC Converter MM3370

IL

1V/div.

1A/div.

VOUT

50μ s/div.

IOUT=1.5A Resistive Load

■ Shutdown through Enable

IL

1V/div.

2A/div.

VOUT

50μ s/div.

IOUT=3A Resistive Load

■ Shutdown through Enable

3,403,353,303,253,203,153,103,053,00

VIN=12V

Out

put V

olta

ge(V

)

Output Current(mA)

0 1000 2000 3000

■ LOAD REGULATION

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0.00 5 10 15 20 25 30 35

IOUT=1A

Out

put V

olta

ge (V

)

Input Voltage (V)

■ Line Regulation

0.90.80.70.60.50.40.30.20.1

0-75 -50 -25 0 25 50 75 100

VIN =12V VEN =0V

Shut

dow

n Su

pply

Cur

rent

(μA)

Tempetature(°C)

■ Shutdown Supply Current -Temperature

20181614121086420

-75 -50 -25 0 25 50 75 100

Sup

ply

Cur

rent

(mA

)

Temperature(°C)

VIN=12V VEN =3V

■ Supply Current -Temperature

• Any products mentioned in this catalog are subject to any modification in their appearance and others for improvements without prior notification.• The details listed here are not a guarantee of the individual products at the time of ordering. When using the products, you will be asked to check their specifications.

MITSUMI High Voltage Operation Step-down DCDC Converter MM3370

0.90.80.70.60.50.40.30.20.1

0-75 -50 -25 0 25 50 75 100

Temperature(°C)

Shu

tdow

n S

uppl

y C

urre

nt(μ

A)

VEN=OV

VIN=12V

VIN=27V

■ Shutdown Supply Current -Temperature

35

30

25

20

15

10

5

0-75 -50 -25 0 25 50 75 100

Tempetature(°C)

Supp

ly C

urre

nt (m

A)

VEN=3V

VIN=27V

VIN=12V

VFB=1.4V

■ Supply Current -Temperature

1.00

0.95

0.90

0.85

0.80-75 -50 -25 0 25 50 75 100

VEN=3V

Temperature(°C)

Feed

back

Vol

tage

(V)

VIN=27V

VIN=12V

■ Feedback Voltage-Temperature

VEN=3V VFB=0.85V700

650

600

550

500

450

400

350

300-75 -50 -25 0 25 50 75 100

Temperature(°C)

Osc

illatio

n Fr

eque

ncy(

kHz)

VIN=12V

VIN=27V

■ Oscillation Frequency-Temperature

VIN=27V

VIN=12V

VEN=0V VSW=0V0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0.0-75 -50 -25 0 25 50 75 100

Temperature(°C)

Hig

h-Si

de S

witc

h Le

akag

e C

urre

nt(n

A)

■ High-Side Switch Leakage Current-Temperature