AM7228

Motor Driver ICs

http://www.amtek-semi.com

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Specifications subject to change without notice

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Reducing the noise of hall signal

Hall element may be affected by the depending on the wiring pattern of board. In this case, place a

capacitor like C1 in Fig.10. In addition, when wiring from the hall element output to IC hall input is

long, noise may be loaded on wiring. In this case, place a capacitor like C2 in Fig.10.

Fig.10 Application in the vicinity of hall signal

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.10 Timing chart in PWM control

When the voltage input to PWM terminal applies

H logic : normal operation

L logic : H side output is off

When PWM terminal is open, H logic is applied.

PWM terminal has hysteresis of 100mV (Typ.).

If H logic is applied to PWM terminal before VCC voltage is applied to IC, current flows to VCC

terminal through ESD protection diode inside PWM terminal, resulting in malfunction may possibly

occur.

When VCC voltage is not apply to IC, do not apply voltage to PWM terminal.