Single Phase Full-Wave Motor Driver with Built-in Hall …AM308.pdf/...Single Phase Full-Wave Motor Driver with Built-in Hall Sensor for Fan Motor The AM308 is a single phase full-wave

AM308

Motor Driver ICs

http://www.amtek-semi.com SEP. 22001144 VV11..00

Specifications subject to change without notice - 1 -

Single Phase Full-Wave Motor Driver with

Built-in Hall Sensor for Fan Motor

The AM308 is a single phase full-wave fan motor driver IC with built-in hall sensor. Rotation speed

can be controlled by PWM input signal. The device contains rotating speed pulse detection output

(FG), output soft switching, lock protection and thermal shutdown protection. Maximum output

current is 1A. The device is available in TSOT26-FL package.

Applications

Single Phase DC Motor.

Features

1) Built-in hall-effect sensor.

2) Operation voltage 2.0 to 6.5V.

3) Direct PWM speed control.

4) Lock detection/Automatic restart circuit.

5) Rotating speed pulse signal (FG) output.

6) Built-in turbo start up (overcome friction).

7) Soft switched drive for silent application.

8) Thermal shutdown protection (TSD).

9) Auto gain control function (AGC).

10) Built-in Hall Signal Offset Cancellation

Technical

11) Stand by Mode (PWM=L>70ms)

Absolute Maximum Ratings (Ta = 25℃)

Parameter Symbol Limits Unit

Supply voltage VCC 8 V

Output maximum current IO(MAX) 1000* mA

Output continuous current IO(CONT.) 400 mA

FG single output voltage VFG 8 V

FG single output current IFG(SINK) 10 mA

Power dissipation Pd 581** mW

Operate temperature range Topr -20～+90 ℃

Storage temperature range Tstg -40～+150 ℃

Junction temperature Tjmax 150 ℃

* This value is not to exceed Pd.

** Reducing by 4.65 mW/℃ over 25℃ (On 114.3mm X 76.1mm X 1.6mm single layer board)

Exceeding the absolute maximum ratings may cause permanent damage.

Recommended Operating Conditions (Set the power supply voltage taking allowable dissipation into considering)

Parameter Symbol Min Typ Max Unit

Operating supply voltage range VCC 2.0～6.5 V

AM308

Motor Driver ICs



Electrical Characteristics

(Unless otherwise specified, Ta = 25℃, VCC = 5V)

Parameter Symbol Limit

Unit Conditions Min Typ Max

Supply current ICC1 － 10 20 uA PWM=0

ICC2 0.3 0.5 mA PWM under 5%

ICC3 3 6 mA No load on output

ICC Condition (PWM frequency at 25KHz)

PWM duty of ICC1 DICC1 1 1.5 %

PWM duty of ICC2 DICC2 5 7.5 %

PWM

Input H level VPWMH 2.5 － VCC V

Input L level VPWML 0 － 0.7 V

Input frequency FPWM 0.03 － 50 kHz

Output

Output voltage VO － 0.25 0.35 V IO=200mA (Upper + Lower)

FG low voltage VFGL － 0.2 0.3 V IFG(sink) = 3mA

FG leakage current IFGL －－ 10.0 μA VFG = 5V

Magnetic characteristics

Operate point BOP － 30 50 G

Release point BRP -50 -30 － G

Hysteresis BHYST － 60 100 G

Lock protection

Lock detection ON time TON 0.35 0.50 0.65 sec

Lock detection OFF time TOFF 3.5 5.0 6.5 sec

AM308

Motor Driver ICs



Block Diagram

Hall SensorChopper

Amplifier /

Offset

cancellation

AGC

S/H Comparator

Voltage

Reference

Logic

Control

Soft

Switching

Pre

Driver

H-Bridge

Output

Driver

PWM

Lock

ProtectionOscillatorTSD

4

3

12

5

6

Vcc

GND PWM

Out2

Out1

FG

Vcc

500KΩ

Fig.1

Pin Definition and Description

PIN No Pin Name Function

1 PWM PWM signal input terminal

2 GND Ground terminal

3 OUT2 Motor output terminal

4 OUT1 Motor output terminal

5 VCC Power supply terminal

6 FG FG signal output terminal

Fig.2 Pin assignment

AM308

Motor Driver ICs



Magnetic Pole vs. Outputs Behavior

Test conditions PWM OUT1 OUT2 FG Mode

B > BOP H

H L L (Output Tr : ON)

Operation mode B < BRP L H Z (Output Tr : OFF)

B > BOP L

L L L (Output Tr : ON)

B < BRP L L Z (Output Tr : OFF)

B > BOP -

L L L (Output Tr : ON) Lock mode

B < BRP L L Z (Output Tr : OFF)

Z：Open drain output (High impedance)

Supply magnetic direction

Fig.3 Magnetic direction

Hysteresis Characteristics

AM308

Motor Driver ICs



Application Circuit

Direct PWM speed control

FAN speed is controlled by FAN controller PWM output. IC output PWM duty is changed directly

by input PWM signal. H level input is motor active; L level input is motor stop.

Connection of board

VCCGND

Out2 Out1

PWM FG

M

Pull-up resistor

VCC

PWM

ZD1

Option

C1D1

Fig.5 Direct PWM control

Normally, reverse connection of power supply may damage the device. The IC has designed

the (D1) diode in the IC circuit to protect reverse connection. The BEMF causes re-circulate

current to power supply, when power-on or output changes. It may cause VCC terminal to raise

voltage when there is a reverse current protection diode and there is no way to return current

back to power supply. In such case, please take necessary measures like above. Connect a

Zener diode (ZD1) between VCC and GND terminal not to exceed the absolute maximum rating

voltage. Connect a capacitor (C1) between VCC and GND terminal to make a path of return

current to power supply.

Speed control

Direct PWM speed control

Rotation speed of motor can be changed by controlling ON/OFF of the upper output

depending on duty of the signal input to PWM terminal.

Fig.7 Timing chart in PWM control

When the voltage input to PWM terminal applies H logic : normal operation

L logic : H side output is off

AM308

Motor Driver ICs



Lock Detection, Automatic Restart Circuit

This IC detect the rotation of the motor by built-in hall signal, and adjust lock detection ON time (Ton)

and lock detection OFF time (Toff) by the internal counter. These time (Ton, Toff) are showed below.

Fig.9 Lock detect and auto restart motion

Only in Lock detection ON Time (Ton), motor will be rest ordinary motion by switching over of built-in

hall signal. This IC make the lock protection function off, when the PWM input keeps low level for

more than 70ms (typ.).

Fig.10 PWM input signal and lock protect function

Lock protect function does not work if PWM input frequency is slower than 15Hz (typ.)

So, please input faster frequency more than 30Hz.

AM308

Motor Driver ICs



Auto Gain Control (AGC)

The AM308 is built-in a Hall sensor element to sense the magnetic flux density (B). The device

offers fixed current to drive hall sensor, and utilize chopper amplifier circuit to cancel hall sensor

offset. AGC technology with different distance and magnetic force offers stable hall signal. AGC

setting by different VCC value.

Output Soft Switching

The AM308 device includes a soft-switching algorithm that controls the output switching slew rate

for both output pins. As a result the AM308 device is ideal for use in applications requiring low

audible switching noise and low EMI interference.

Turbo start up function

The turbo start-up output will work at PWM Duty 100% in the first 2.5~3 FG cycle. The output duty

doesn’t depend on the PWM terminal input. The function characteristic is showed as blow.

Fig.11 Turbo start up

Power Sequence

PWM voltage need to equal or lower than Vcc while Fan is working. When Power off (Vcc=0V),

PWM need to off to avoid power from PWM to Vcc.

AM308

Motor Driver ICs



PWM Noise Immunity

The IC could mask the unexpected PWM noise to avoid trigger digital circuit to go into lock function.

The PWM noise mask ability is under duty 5% (Typ.) at frequency 25KHz.

FG

PWM

Noise

Power Saving

The IC power consumption (Icc1) is extremely low. Only spend 10uA (Typ.) when PWM is low.

AM308

Motor Driver ICs



● Thermal Information

θja junction-to-ambient thermal resistance 215.15℃/W

Ψjt junction-to-top characterization parameter 2.46℃/W

Θja is obtained in a simulation on a JEDEC-standard 1s0p board as specified

inJESD-51.

The Θja number listed above gives an estimate of how much temperature rise is

expected if the device was mounted on a standard JEDEC board.

When mounted on the actual PCB, the Θja value of JEDEC board is totally different

than the Θja value of actual PCB.

Ψjt is extracted from the simulation data to obtain Θja using a procedure described in

JESD-51, which estimates the junction temperature of a device in an actual PCB.

The thermal characterization parameter,Ψjt, is proportional to the temperature

difference between the top of the package and the junction temperature. Hence, it is

useful value for an engineer verifying device temperature in an actual PCB environment

as described in JEDEC JESD-51-12.

When Greek letters are not available,Ψjt is written Psi-jt.

Definition:

TtTj

PTT dtjjt/)( DFEINITION :

Where :

Ψjt (Psi-jt) = Junction-to-Top(of the package) C/W

Tj= Die Junction Temp. C

Tt= Top of package Temp at center. C

Pd= Power dissipation. Watts

Practically, most of the device heat goes into the PCB, there is a very low heat flow

through top of the package, So the temperature difference between Tj and Tt shall be

small, that is any error caused by PCB variation is small.

This constant represents that Ψjt is completely PCB independent and could be used to

predict the Tj in the environment of the actual PCB if Tt is measured properly.

AM308

Motor Driver ICs



How to predict Tj in the environment of the actual PCB

Step 1 : Used the simulated Ψjt value listed above.

Step 2 : Measure Tt value by using

Thermocouple Method

We recommend use of a small ~40 gauge(3.15mil diameter) thermocouple. The

bead and thermocouples wires should touch the top of the package and be covered

with a minimal amount of thermally conductive epoxy. The wires should be

heat-insulated to prevent cooling of the bead due to heat loss into wires. This is

important towards preventing “too cool” Tt measurements, which would lead to the

calculated Tj also being too cool.

IR Spot Method

An IR Spot method should be utilized only when using a tool with a small enough

spot area to acquire the true top center “hot spot”.

Many so-called “small spot size” tools still have a measurement area of 0~100+mils

at “zero” distance of the tool from the surface. This spot area is too big for many

smaller packages and likely would result in cooler readings than the small

thermocouple method. Consequently, to match between spot area and package

surface size is important while measuring Tt with IR sport method.

Step 3 : calculating power dissipation by

P (VCC–|Vo_Hi – Vo_Lo|) x Iout + VCC x Icc

Step 4 : Estimate Tj value by

Tj= Ψjt x P+Tt

Step 5: Calculated Θja value of actual PCB by the known Tj

Θja(actual) = (Tj-Ta)/P

AM308

Motor Driver ICs



Maximum Power Dissipation (de-rating curve) under JEDEC PCB & actual PCB

AM308

Motor Driver ICs



Packaging outline --- TSOT26-FL Unit : mm

A1

E

A

D

Sensor Location

e

e1

E11.344

0.7

69

B B

With Plating

c1 c

b1

b

SECTION B-B

SYMBOL MILLIMETERS INCHES

Min. Max. Min. Max.

A 0.70 0.80 0.028 0.031

A1 0.35 0.45 0.014 0.018

b 0.30 0.50 0.012 0.020

b1 0.30 0.45 0.012 0.018

c 0.11 0.20 0.004 0.008

c1 0.11 0.15 0.004 0.006

D 2.70 3.10 0.106 0.122

E 3.40 3.80 0.134 0.149

E1 1.50 1.70 0.060 0.067

e 0.95 BSC 0.037 BSC

e1 1.90 BSC 0.075 BSC

AM308

Motor Driver ICs



Application Note

1) Absolute maximum ratings

This product is produced with strict quality control, but destroyed in using beyond absolute

maximum ratings. Once IC destroyed, a failure mode cannot be defined (like short-mode or

open-mode).Therefore, physical security counter measure, like fuse, is to be given when a

specific mode to be beyond absolute maximum rating is considered.

2) Connecting the power supply connector backward

Connecting of the power supply in reverse polarity can damage IC. Take precautions when

connecting the power supply lines. An external direction diode can be added.

3) Power supply line

The BEMF causes re-circulate current to power supply, Please connect a capacitor between

power supply and GND as a route of re-circulate current. And please determine the

capacitance after confirmation that the capacitance does not causes any problems.

4) GND potential

The GND terminal should be the location of the lowest voltage on the chip.

5) Thermal design

Use a thermal design that allows for a sufficient margin in light of the power dissipation in

actual operating conditions.

6) Mounting failures

Mounting failures, such as misdirection or miss-mounts, may destroy the device.

The electrical short caused by falling particle, between outputs; power supply and output; or

output and ground, may damage the device. Inter-pin shorts and mounting errors.

7) Actions in strong electromagnetic field

Use caution when using the IC in the presence of a strong electromagnetic field as doing so

may cause the IC to malfunction.

8) ASO

When using the IC, set the output transistor so that it does not exceed absolute maximum

rations or ASO.

AM308

Motor Driver ICs



Condition of Soldering

1). Manual Soldering

Time / Temperature ＜ 3 sec / 400 + 10 oC （2 Times）

Test Results：0 fail/ 22 tested

Manual Soldering count：2 Times

2). Re-flow Soldering (follow IPC/JEDEC J-STD-020D)

Classification Reflow Profile

Profile Feature Pb-Free Assembly

Average ramp-up rate (TL to TP) 3oC/second max.

Preheat

- Temperature Min (Ts min)

- Temperature Max (Ts max)

- Time (ts) from (Tsmin to Tsmax)

150oC

200oC

60-120 seconds

Ts max to TL

- Temperature Min (Ts min)

3oC/second max.

Time maintained above:

- Liquid us temperature (TL)

- Time (tL) maintained above TL

217oC

60-150 seconds

Peak package body temperature (Tp) 260 +0/-5oC

Time with 5oC of actual Peak

- Temperature (tp)

30 seconds

Ramp-down Rate 6oC/second max.

Time 25oC to Peak Temperature 8 minutes max.

Test Results：0 fail/ 32 tested Reflow count：3 cycles

AM308

Motor Driver ICs



Marking Identification

DPKD27

Pin1 mark

Row1

Row 1

Date & Lot number

Week

Year-A:0,B:1 … J:9

E.g. 2012:C, 2013:D

Lot No

Device code : D = AM308

Explanation:

EQWD27

D : AM308

PK: Production Serial number

D: 2013

27: Week

Documents

Single Phase Full-Wave Motor Driver with Built-in Hall …AM308.pdf/...Single Phase Full-Wave Motor Driver with Built-in Hall Sensor for Fan Motor The AM308 is a single phase full-wave