LB8500M

No.8336-10/15

Application Example 3

[Fixed Speed + Soft Start]

With this circuit, the motor speed remains constant even if there are fluctuations in the supply voltage or static voltage.

CTL signal (PWM duty)

C pin voltage

(RPM)

0%

20%

100%

80%

60%

40%

Motor

full speed

6V

Input a fixed-duty signal to the CTL pin signal input as an input signal for which soft start is enabled at startup.

Alternatively, apply a constant voltage to the C pin. (In this case, the CTL pin must be left open.)

LB8500M

Driver IC

12V

VCC

6VREG

VREG

EDGE

FGIN

FGIN

EI

EO

FG

VTH

C

GND

One-shot

multivibrator

CTL

LIM

RC

CTL signal

VREF

CTL

180k

Ω