Hi TI Technical Support Team,
I designed a board to contol hobby DC motors using DRV8837. Motor is 3-6V ~100rpm DC motor and draws around 150mA at full load. I am powering motor driver's Vm and Vcc from different 3.3V supply. I am using two MP2161 (DC DC buck converter) to generate Vm and Vcc voltage of DRV8837. I am using power sequencing. Firstly, Vcc voltage is generated (+3V3_board), then PG pin of this converter is used to enable MP2161 that generates motor voltage (+3V3_Motor). I am making In1 and In2 inputs of the DRV8837 "HIGH" at the start. I have attached the schematic this thread. MP2161 outputs are 3.3V as expected.
The problem is when I am powering the system, although In1 and In2 are HIGH (brake mode), motor spins for short time and then stops(and behaves as expectedly). I also made In1 and In2 LOW, but same behaviour (short motor rotation at the start) was seen when the board is powered on. Is there any solution for this problem, how can I make sure that motor will not rotate at the start?
Thank you for your help in advance,
Regards,
Ahmet
