IP9001

4-CH MOTOR DRIVE IC FOR PORTABLE CDP

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APPLICATION SUMMARY (Continued)

Power supply driving circuit detects a maximum output voltage among the 4-CH output pins, and then

control external PNP TR to reduce the power consumption.

This buck converter consists of external PNP TR, Schottky barrier diode, Inductor, and capacitors.

When the sensing voltage of SENS(pin1) falls below detecting voltage, then EMP(pin35) goes from High

level to low level. The detector voltage has 50mV hysteresis.

According to the SEL(pin42) voltage level, the detector voltage varies as following table,

3. PWM power supply driving circuit

Figure2. PWM power supply driving circuit

4. Empty detector circuit

SEL

Detector voltage

Return voltage

LOW

2.2V typ

2.25V typ

High-impedance

1.8V typ

1.85V typ

Table4. EMP detector voltage