Other Parts Discussed in Thread: TEST2,
Hi team,
My customer is using DRV8832. The scheamtic is as below.
F_VCC = 3.6V
Please note that R33 is not soldered so VSET=VREF=1.285V and the desired output voltage=Vout=1.285*4=5.14V which is larger than F_VCC. So DRV8832 will operate in 100% duty cycle which makes actual output voltage=F_VCC=3.6V.
Motor spec:3.6V rated voltage,stall current=330mA
We found below different behavior on Fault pin:
Test1:set Rsense=1ohm,so current limit=200mA. When the motor stalls, Isense pin gets to 200mV limit and the fault pin can assert.
Blue=Isense pin voltage
Yellow=Fault pin voltage
Test2:set Rsense=0.75ohm,so current limit=266mA. When the motor stalls, Isense pin gets to 200mV limit but the fault pin didn't assert.
Blue=Isense pin voltage
Yellow=Fault pin voltage
Could you please help analyze why fault pin cannot assert when we set Rsense to 0.75ohm?
Best regards,
Wayne