AM2908

Motor Driver ICs

AMtek semiconductors

July. 2020 V0.2

- 6 -

1. C1、C2: Power supply PVCC/VCC pin capacitor:

a) The capacitor can reduce the power spike when the motor is in motion. To avoid the IC directly

damaged by the PVCC/VCC peak voltage. It also can stabilize the power supply voltage and reduce its

ripples.

b) The C1 capacitor can compensate power when motor starts running.

c) The capacitor value (μF) determines the stability of the PVCC/VCC during motor in motion. In general,

100μF capacitor is enough in low voltage power (PVCC)；0.1μF capacitor is enough in low voltage

power (VCC). If the large voltage power or a heavy loading motor is used, then a larger capacitor would

be needed.

d) On the PCB configuration, the C1、C2 must be mounted as close as possible to VCC/PVCC pin

(PIN2/PIN6).

2. In order to use PWM current control, a 100mΩ sense resistor is placed between the PGA/PGB pin and

ground for current sensing purposes. The ground-trace should be as short as possible. For 100mΩ sense

resistors, the ground-trace voltage drops in the PCB can be significant, and should be taken into account.

The sense resistor setting 100mΩ at maximum load. During overcurrent events, this rating may be

exceeded for short durations.

STBY

0.1uF

C2

100

μF

C1

C5

100nF

C4

PVCC

1

2

3

4

12

INB

5

13

14

15

16

STBY

nFAULT

OUTB

OUTB

PGB

VCC

CPB

CPA

VCP

6

PVCC

7

GND

8

PGA

9

OUTA

10

11

OUTA

INA

INB

INA

nFAULT

AM2908

0.1Ω

R1

100nF

10K

R2

3.3V