DRV 8733 Problem

Ayush Jain1

Other Parts Discussed in Thread: DRV8837

Dear Friends,

I am using DRV8837 to drive 9V dc motor consuming max 120mA current. Vm is connected to 9V battery.To generate 3.3V logic voltage I have used TPS70933. Everything is working fine when motor is running free but as soon as I load motor, regulator heats up instantaneously. Vm cap and vcc cap for drv8837 is 0.1uF.Kindly please suggest solution for this problem.

Thanks a lot.

over 10 years ago

0 Rick Duncan over 10 years ago

TI__Guru** 114905 points

Hi Ayush,

Can you provide a schematic?
Can you provide a scope capture of VCC of the DRV8837, and VM at the TPS70933?
How much current is the motor using when loaded?

0 Ayush Jain1 over 10 years ago in reply to Rick Duncan

Prodigy 250 points

Hi Rick,

Thx for your immediate reply. I have attached all required images.

0 RE over 10 years ago in reply to Ayush Jain1

TI__Mastermind 20985 points

Ayush, VM might be dropping more than you think. I recommend zooming in the time scale. Try simply adding a much bigger capacitor on VM (e.g. 10uF) and see if the problem goes away.

Best regards,
RE

0 Ayush Jain1 over 10 years ago in reply to RE

Prodigy 250 points

Problem is solved with 47uF cap at Vm pin. Thx a lot.

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DRV 8733 Problem