DRV10974: Initial operating issue

CHO SR

Expert 2935 points

Part Number: DRV10974
Other Parts Discussed in Thread: DRV10987, DRV10975

Hi,

The customer uses the DRV10974 for the hot water mat motor control.

Stop after 1 to 2 seconds of motor initial operation.(current 0.9A)

Current Limit : 115kohm(1,400mA)

Motor phase resistance : 8.8ohm

BEMF : 2.9V(1500RPM)

However, it will work if the current limit resistor is modified to 12K or less.

Please review the schematic and give me advice on the problem.

Schematic : 7026.Schematic.pdf

Layout :

Normal waveform

Failed waveform

10 months ago

0 Vishnu Balaraj 10 months ago

TI__Mastermind 24405 points

Hi CHO,

At 12k the current limit is around 0.3A. Phase current looks much cleaner and stable at 12k as the closed loop current is very low. At 115k, current limit is much higher so the torque is not controlled and the device might lose sync and trigger fault.

Regards,

Vishnu

0 CHO SR 10 months ago in reply to Vishnu Balaraj

Expert 2935 points

Hi Vishnu,

The customer had a motor initial operation problem with the BD63242FV(ROHM) driver.

DRV10974 was selected because the starting current limit could be greater than 1.4 A.

There is no improvement in the RADV, RRMP change test.

Please help me operate 1.4A.

+1 Vishnu Balaraj 10 months ago in reply to CHO SR

TI__Mastermind 24405 points

CHO,

I would recommend checking DRV10975 or DRV10987 as these drivers have higher current capability.

Regards,

Vishnu

0 CHO SR 9 months ago in reply to Vishnu Balaraj

Expert 2935 points

Vishnu,

Thank you.

The customer will review DRV10975.

0 Vishnu Balaraj 9 months ago in reply to CHO SR

TI__Mastermind 24405 points

Thanks!

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DRV10974: Initial operating issue