DRV8323: Bulk capacitor sizing

Arthur Siqueira

Part Number: DRV8323
Other Parts Discussed in Thread: CSD88599Q5DC

Hello,

I'm planning to use three DRV8323s to drive three BLDC motors on one PCB of around 11x8 cm^2. So based on that, I was wondering how could I best size the bulk capacitors for the motors.
I'm driving the motors at 24V, and their nominal current is: 2A (peaking at 6A) for two motors and the other one is around 4A nominal.
They've worked fine with the 330uF capacitors on the DRV8323 development board, but we were considering to decrease their size significantly for our application.

over 4 years ago

0 Adam Sidelsky over 4 years ago

TI__Guru 63340 points

Arthur,

This is highly dependent on your system and the motor/application.

I would try a bulk capacitance and check if there is too much power supply ripple in which case you should increase the bulk capacitance.

Regards,

-Adam

0 Arthur Siqueira over 4 years ago in reply to Adam Sidelsky

Prodigy 40 points

Hi Adam,

Would you know what are the main factors that should help me find a proper minimum initial capacitor value for driving those motors?
Additionally, apart from the specs I've posted before, I'm also driving the DRV8323 with 20kHz PWM signals, I'm using TI's CSD88599Q5DC as my half-bridges, and the electrical speed of my motor is around 48000eRPM.

0 Daniel De Sousa over 4 years ago in reply to Arthur Siqueira

Intellectual 580 points

Hi Arthur,

I think something like the EEE-FTV151XAV from Panasonic would work for your application.

Let me know,

Daniel

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DRV8323: Bulk capacitor sizing