Diodes AM9789 User Manual

Single Phase Full-wave Motor Driver for Silent Fan Motor AM9789

Data Sheet

General Description

The AM9789 is a single-phase, full wave motor
driver suited for DC fan motor, and its speed is
controlled by PWM input signal. It is suitable for
both game machine and CPU cooler which need
silent drivers. It features lock protection, thermal
shutdown, PWM control, low noise and so on.

The AM9789 is available in MSOP-8, MSOP-10
DFN-3×3-8 and DFN-3×3-10 packages.

Features

• BTL Output Single-phase Full-wave Linear
Driver

• Silent Driver

• Low Supply Current (Normal Operation，Less
than 4mA)

• Low Standby Current (PWM=0 Duty) @

Supply Current Less than 200µA

• Speed Controllable by PWM Input Signal

• Built-in Quick Start Function

• Built-in Lock Protection and Auto Restart

Function

• Built-in Hall Bias Circuit

• Built-in FG Output

• Built-in Thermal Shutdown Circuit

• Built-in Over Current Protection Circuit

Applications

• Silent Fan Motors

MSOP-8 MSOP-10 DFN-3×3-8 DFN-3×3-10

Figure 1. Package Types of AM9789

Oct. 2012 Rev. 1. 1 BCD Semiconductor Manufacturing Limited

1

Data Sheet

Single Phase Full-wave Motor Driver for Silent Fan Motor AM9789

Pin Configuration

M8 Package MM Package

(MSOP-8) (MSOP-10)

1

2

3

4

DN8 Package DN Package
(DFN-3×3-8) (DFN-3×3-10)

Pin 1 Mark

1

2

3

45

Pin Description

8

7

6

5

8

7

6

1

2

3

4

5

Pin 1 Mark

1

2

3

4

56

Figure 2. Pin Configuration of AM9789 (Top View)

10

9

8

7

6

10

9

8

7

Pin Number

MSOP-10/

DFN-3×3-10

MSOP-8/

DFN-3×3-8

Pin Name Function

1 1 OUT2 Output Connection 2
2 NC No connected
3 3 HIN+ Hall input(+). Connect to Hall element positive output
4 HB Hall bias
5 4 HIN- Hall input(-). Connect to Hall element negative output
6 5 FG Rotation speed output
7 6 PWM PWM signal input terminal
8 2 VCC Power supply
9 7 OUT1 Output Connection 1

10 8 GND Ground

Oct. 2012 Rev. 1. 1 BCD Semiconductor Manufacturing Limited

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Data Sheet

Single Phase Full-wave Motor Driver for Silent Fan Motor AM9789

Functional Block Diagram

Figure 3. Functional Block Diagram of AM9789

Oct. 2012 Rev. 1. 1 BCD Semiconductor Manufacturing Limited

3

Data Sheet

Single Phase Full-wave Motor Driver for Silent Fan Motor AM9789

Ordering Information

AM9789 -

Circuit Type

Package
M8: MSOP-8
MM: MSOP-10
DN8: DFN-3×3-8
DN: DFN-3×3-10

Package Temperature Range Part Number Marking ID Packing Type

G1: Green

TR: T ape & Reel

MSOP-10

MSOP-8 AM9789M8TR-G1 9789M8-G1 Tape & Reel

-40 to 105°C

DFN-3×3-8 AM9789DN8TR-G1 B6E Tape & Reel

DFN-3×3-10 AM9789DNTR-G1 BFD Tape & Reel

BCD Semiconductor's Pb-free products, as designated with "G1" suffix in the part number, are RoHS compliant
and green.

AM9789MMTR-G1 9789MM-G1 Tape & Reel

Oct. 2012 Rev. 1. 1 BCD Semiconductor Manufacturing Limited

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Data Sheet

Single Phase Full-wave Motor Driver for Silent Fan Motor AM9789

Absolute Maximum Ratings (TA=25°C, Note 1)

Parameter Symbol Value Unit

Supply Voltage VCC 10 V
Output Current I
Output Voltage V
HB Output Current IHB 10 mA
FG Output Voltage VFG 10 V
FG Output Sink Current IFG 10 mA
Operation T emperat ure TOP -40 to 125
Storage Temperature Range T
Lead T em perature (Soldering 10s) T

Thermal Resistance (Junction to
Ambient)

Thermal Resistance (Junction to Case)

Power Dissipation P

ESD (Human Body Model)
ESD (Machine Model)

1 A

OUT

10 V

OUT

°C

-55 to 150

STG

260

LEAD

MSOP-8 205

θ

JA

θ

JC

D

MSOP-10 195

DFN-3x3-8 71

DFN-3x3-10 71

MSOP-8 48

MSOP-10 46

DFN-3x3-8 48

DFN-3x3-10 48

MSOP-8 585

MSOP-10 585

DFN-3x3-8 1760

DFN-3x3-10 1760

4000

400

°C
°C

°C/W

°C/W

mW

V
V

Note 1: Stresses greater than those listed under “Absolute Maximum Ratings” may cause permanent damage to
the device. These are stress ratings only, and functional operation of the device at these or any other conditions
beyond those indicated under “Recommended Operating Conditions” is not implied. Exposure to “Absolute
Maximum Ratings” for extended periods may affect device reliability.

Recommended Operating Conditions (TA=25°C)

Parameter Symbol Min Max Unit

Supply Voltage VCC 2 6 V
Hall Input Voltage Range VHB 0.4 VCC -1.1 V
Operating Ambient Temperature TA -40 105

Oct. 2012 Rev. 1. 1 BCD Semiconductor Manufacturing Limited

5

°C

Data Sheet

Single Phase Full-wave Motor Driver for Silent Fan Motor AM9789

Electrical Characteristics

V

=5V, TA=25°C, unless otherwise specified.

CC

Parameter Symbol Conditions Min Typ Max Unit

Operation Current I
Standby Current I

Rotation Mode 2 4 mA

CC1

V

CC2

=0 130 200

PWM

µA
HB Pin Output Voltage VHB IHB=5mA 1.1 1.3 1.5 V
Lock Detection ON Time tON 0.3 0.4 0.5 s
Lock Detection OFF Time t

3 4 5 s

OFF

Quick Start Enable Time tQS 55 75 ms
Output Drivers Saturation

Voltage

V

SAT(H+L)

Input-Output Gain GIO V

I

=250mA, upper

OUT

and lower total

/(V

OUT

HIN+-VHIN-

0.5 0.7 V

) 44 47 50 dB
FG Pin Low Voltage VFG IFG=5mA 0.2 0.3 V
FG Pin Leakage Current I

PWM Input High Level
Voltage
PWM Input Low Level
Voltage

PWM Input Frequency f
Hall Input Offset Voltage V

Hall Input Hysteresis
Voltage
Thermal Protection
Temperature

Thermal Hysteresis Width

VFG=5V 0.1 1

FGL

V

PWMH

V

PWML

PWM

V

T

△T

HOFS

HYS

SD

SD

0.5×V

CC

V

V

CC

0 0.2×VCC V

0.02 50 kHz
±10 mV

±5 ±10 ±15 mV

165
30

µA

°C
°C

Oct. 2012 Rev. 1. 1 BCD Semiconductor Manufacturing Limited

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Data Sheet

Single Phase Full-wave Motor Driver for Silent Fan Motor AM9789

Typical Performance Characteristics

4.0

3.5

Operation Mode

3.0

V

PWM=VCC

2.5

2.0

1.5

Supply Current (mA)

1.0

0.5

0.0
0123456

Supply Voltage (V)

200

150

100

Supply Current (µA)

50

0

0123456

Standby Mode
V

PWM

=0V

Supply Voltage (V)

Figure 4. Supply Current vs. Supply Voltage (V

PWM=VCC

) Figure 5. Supply Current vs. Supply Voltage (V

PWM

800

600

V

SAT-H

V

SAT-L

400

200

Saturation Voltage (mV)

0

0 100 200 300 400 500

Output Current (mA)

800

700

600

500

400

300

Power Dissipation (mW)

200

100

0

-40 -20 0 20 40 60 80 100 120 140

Ambient Temperature (oC)

Figure 6. Saturation Voltage vs. Output Current Figure 7. Power Dissipation vs. Temperature (MSOP)

Package: MSOP-10/MSOP-8

=0V)

Oct. 2012 Rev. 1. 1 BCD Semiconductor Manufacturing Limited

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Data Sheet

Single Phase Full-wave Motor Driver for Silent Fan Motor AM9789

Typical Performance Characteristics (Continued)

2000

1500

Package: DFN-3x 3-10/DFN-3x3-8

1000

500

Power Dissipation (mW)

0

-40 -20 0 20 40 60 80 100 120 140

Ambient Temperature (oC)

Figure 8. Power Dissipation vs. Temperature (DFN)

Oct. 2012 Rev. 1. 1 BCD Semiconductor Manufacturing Limited

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Data Sheet

Single Phase Full-wave Motor Driver for Silent Fan Motor AM9789

Truth Table

INPUT OUTPUT

HIN- HIN+ PWM OUT1 OUT2 FG

L H
H L L H OFF
H L
L H L L L
L H
H L L L OFF

- -

H

L

-

L OFF OFF OFF Standby Mode

H L L

L L OFF

L L OFF

Mode

Operation Mode

Lock Mode

Oct. 2012 Rev. 1. 1 BCD Semiconductor Manufacturing Limited

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Data Sheet

Single Phase Full-wave Motor Driver for Silent Fan Motor AM9789

T ypical Application

For MSOP-10 package

Oct. 2012 Rev. 1. 1 BCD Semiconductor Manufacturing Limited

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Data Sheet

Single Phase Full-wave Motor Driver for Silent Fan Motor AM9789

T ypical Application (Continued)

For MSOP-8 package

Figure 9. Typical Applications of AM9789 (Note 2)

Note 2:
D1 is an ordinary diode used to filter the noise from VCC and protect IC if VCC and GND are plugged reversed.

C1=1µF/10V typical.
R1 and R2 should be fine tuned based on system design. They can be removed according to the system
requirements.
Zener diode (D2) is an optional choice.
R

=10kΩ typical.

FG

Oct. 2012 Rev. 1. 1 BCD Semiconductor Manufacturing Limited

11

5V/div

Data Sheet

Single Phase Full-wave Motor Driver for Silent Fan Motor AM9789

Application Information

1. Reverse Connection of Power Supply
Connector

Reverse connection of power supply connector may
break IC. Some methods such as inserting a diode
between power supply and VCC terminal can be
taken to avoid the reverse connection destruction.

2. Power Supply Line

Back electromotive force (EMF) causes regenerated
current to the power supply line, so insert a capacitor
(recommended value: 1µF or larger) as close as
possible to the space between the power supply pin
(VCC pin) and ground pin (GND pin) for routing
regenerated current.

3. GND Potential and External Components

Ensure that the potential of GND terminal is the
minimum potential in any operating condition.
External components connected to the ground must
be connected with lines that are as short as possible
and external components connected between IC pins
must be placed as close to the pins as possible.

4. Mounting Failures

In the process of attaching IC to the printed board,
more attention must be paid to the direction and
location of the IC, since mounting failures may also
break IC. In addition, destruction is also possible
when the circuit is shorted by foreign substance
between outputs or between output and power supply
or between output and GND.

5. Thermal Consideration

Refer to Figure 7 “Power Dissipation vs. Ambient
Temperature (MSOP-10/MSOP-8)”, the IC is safe to
operate below the curve and the thermal protection
will be caused if the operating area is above the line.
For example, when T
dissipation is about 0.35W.

The power dissipation can be calculated by the
following equation:
P

D=VSAT(H+L)×IOUT+VCC×ICC

For example, VCC=5V, ICC=2mA, I
V

SAT(H+L)

The GND pin provides an electrical connection to the
ground and channeling heat away. The printed circuit
board (PCB) forms a heat sink and dissipates most of

Oct. 2012 Rev. 1. 1 BCD Semiconductor Manufacturing Limited

=75°C, the maximum power

A

=0.5V, then PD=0.135W.

=250mA,

OUT

the heat to the ambient air.

6. Thermal Shutdown Circuit

Considering the power dissipation under actual
operating condition, the thermal design must be
applied with sufficient margin.

AM9789 features thermal shutdown (TSD) circuit
(operation temperature is 165°C typical and
hysteresis width is 30°C typical). When the chip
temperature reaches the TSD circuit temperature, the
output terminal becomes an open state. TSD circuit is
designed simply for the purpose of intercepting IC
from overheating. Make sure that the IC should not
be used again after this circuit operating. Figure 10
shows a fan rotates normally first and then enters into
OTP mode since the chip temperature reaches 165°C.
Finally the chip temperature decreases below 135°C,
then OTP mode is canceled and the fan rotates
normally again.

V

OUT1

5V/div

V

OUT2

V

FG

5V/div

Time 1s/div

Figure 10. OTP Function

7. Over Current Protection

The driver current is detected by AM9789 internal
circuit. When the output current is over 1A or larger,
AM9789 will close the output driver. After that if the
output current decreases, AM9789 will enable the fan
to rotate again. Figure 11 shows the detailed process.

V

OUT1

5V/div

V

OUT2

5V/div

V

FG

5V/div

Time 1s/div

Figure 11. OCP Function

8. PWM Mode

The output transistor is on when a high-level voltage
is input to the PWM pin, and is off when a low-level
voltage is input. PWM controls the speed of the
motor by inputting the pulse in accordance with the
duty cycle to the PWM pin. When the motor is

12

Data Sheet

Single Phase Full-wave Motor Driver for Silent Fan Motor AM9789

V

Application Information
(Continued)

operated with the PWM pin open, the built-in resistor
enables the PWM pin to change to high-level voltage
and the motor speed rises to full speed. When the
PWM pin is fixed at low-level voltage, the motor
decelerates, and after the motor stops, it enters
“Power Saving Mode”. Figure 12 shows a rotating
fan’s waveform at PWM Mode. Figure 13 shows
Lock Mode Waveform at PWM input condition in the
same fan.

V

OUT1

5V/div

V

OUT2

5V/div

V

FG

5V/div

IIN

200mA/div

Figure 12. PWM Mode Waveform

(PWM: 50% duty cycle, V

V

OUT1

5V/div

V

OUT2

5V/div

VFG

5V/div

200mA/div

I

IN

Figure 13. Lock Mode at PWM Input Condition

(PWM: 50% duty cycle, V

9. Frequency Generator Function

The FG pin is an open collector output, connecting a
pull-up resistor to a high level voltage for the
frequency generator function. During the lock mode,
FG pin output will be always high. Open the terminal
when not in use. Figure 14 shows how this function
works.

Oct. 2012 Rev. 1. 1 BCD Semiconductor Manufacturing Limited

Time 10ms/div

=5V, VL=0V)

H

Time 2s/div

=5V, VL=0V)

H

OUT1

2V/div

V

OUT2

2V/div

V

FG

2V/div

I

200mA/div

IN

Figure 14. Rotation Mode Waveform

Time 2ms/div

10. Lock Protection and Auto-restart

The IC detects the rotation of the motor by Hall
signal and the lock detection ON time (t
time (t

) are adjusted by the internal counter. As

OFF

) and OFF

ON

showed below.

V

OUT1

2V/div

V

OUT2

2V/div

V

FG

2V/div

I

IN

200mA/div

Figure 15. Lock Mode Waveform

Time 2s/div

11. Quick Start and Standby Mode

The IC will enter standby mode when PWM input
keeps low level for more than 55ms (typ.). In standby
mode, shutdown amplifier and FG will be shutdown,
and the supply current is around 130µA. In standby
mode, the lock protection function doesn’t work; the
fan will restart when released from standby mode.
Figure 16 describes this function.

Figure 16. Quick Start and Standby Mode

13

Data Sheet

Single Phase Full-wave Motor Driver for Silent Fan Motor AM9789

Mechanical Dimensions

MSOP-10 Unit: mm(inch)

)

)

7

9

8

9

1

1

.

.

0

0

(

(

0

0

5

5

7

0

.

.

4

5

Note: Eject hole, oriented hole and mold mark is optional.

Oct. 2012 Rev. 1. 1 BCD Semiconductor Manufacturing Limited

0.180(0.007)

0.280(0.011)

2.900(0.114)

3.100(0.122)

0.500(0.020)
TYP

)

1

0

0

.

0

(

0

2

0

.

0

0

0

3

2

.

0

)

)

4

2

1

2

1

1

.

.

0

0

(

(

0

0

0

0.400(0.016)

0.800(0.031)

)

6

0

0

.

0

(

0

5

1

.

0

14

0

9

1

.

.

2

3

0

°
°

6

)

9

0

0

.

0

(

5

0

(

0

.

0

3

0

0

.

7
9

5

0

0

.

0

.

8

2

0

1

.

1

0

0

)
)

(

0

.

0

3

7

.

0

3

2

)

(

0

(

0

.

0

4

3

)

)

4

0

0

.

0

(

0

9

0

.

Data Sheet

Single Phase Full-wave Motor Driver for Silent Fan Motor AM9789

Mechanical Dimensions (Continued)

MSOP-8 Unit: mm(inch)

4.700(0.185)

5.100(0.201)

Note: Eject hole, oriented hole and mold mark is optional.

Oct. 2012 Rev. 1. 1 BCD Semiconductor Manufacturing Limited

0.300(0.012)TYP

0.650(0.026)TYP

2.900(0.114)

3.100(0.122)

`

P

Y

T

)

6

0

0

.

0

(

0

5

1

.

0

)

)

4

2

1

2

1

1

.

.

0

0

(

(

0

0

0

0.410(0.016)

0.650(0.026)

)

)

8

0

0

0

0

0

.

.

0

0

(

(

0

0

0

0

0

2

.

.

0

0

15

0

9

1

.

.

2

3

0

°

6

°

(

0

.

0

3

0

0

.

7

6

0

0

.

9

7

0
0

0

.

8

0

1

.

2

0

0

)

3

8

)

(

0

.

0

(

0

.

0

3

1

)

.

0

4

7

)

(

0

Data Sheet

Single Phase Full-wave Motor Driver for Silent Fan Motor AM9789

Mechanical Dimensions (Continued)

DFN-3×3-8 Unit: mm(inch)

2.900(0.114)

3.100(0.122)

Pin 1 Mark

2.900(0.114)

3.100(0.122)

1.400(0.055)

1.600(0.063)

0.153(0.006)

0.253(0.010)

0.700(0.028)

0.800(0.031)

0.000(0.000)

0.050(0.002)

Oct. 2012 Rev. 1. 1 BCD Semiconductor Manufacturing Limited

16

0.180(0.007)

0.300(0.012)

N5

N4

0

5

0

6

.

0

(

.

6

0

)

2

C

S

B

N8

N1

DETAIL A

12

12 12

Pin 1 options

0.375(0.015)

0.575(0.023)

2.

(0.087 )

200

2.400(0.094)

PIN #1 IDENTIFICATION

See DETAIL A

Data Sheet

Single Phase Full-wave Motor Driver for Silent Fan Motor AM9789

Mechanical Dimensions (Continued)

DFN-3×3-10 Unit: mm(inch)

0.700(0.028)

0.800(0.031)

2.900(0.114)

3.100(0.122)

Pin 1 Mark

0.000(0.000)

0.050(0.002)

2.900(0.114)

3.100(0.122)

1.600(0.063)

1.800(0.071)

0.200(0.008)

0.300(0.012)

0.500(0.020)
TYP

N6 N10

2.300(0.090)

2.500(0.098)

N5

0.300(0.012)

0.500(0.020)

N1

DETAIL A

PIN #

1 IDENTIFICATION

See DETAIL A

0.153(0.006)

0.253(0.010)

12

12 12

Pin 1 options

Oct. 2012 Rev. 1. 1 BCD Semiconductor Manufacturing Limited

17

BCD Semiconductor Manufacturing Limited

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IMPORTANT NOTICE

BCD Semiconductor Manufacturing Limited reserves the right to make changes without further notice to any products or specifi-

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cations herein. BCD Semiconductor Manufacturing Limited does not assume any responsibility for use of any its products for any

cations herein. BCD Semiconductor Manufacturing Limited does not assume any responsibility for use of any its products for any

particular purpose, nor does BCD Semiconductor Manufacturing Limited assume any liability arising out of the application or use

particular purpose, nor does BCD Semiconductor Manufacturing Limited assume any liability arising out of the application or use

of any its products or circuits. BCD Semiconductor Manufacturing Limited does not convey any license under its patent rights or

of any its products or circuits. BCD Semiconductor Manufacturing Limited does not convey any license under its patent rights or

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