Dear TI experts,
My customer considers DRV8874 for their new product.
In the EVM, there is C1 capacitor, 100uF/50V aluminium capacitor.
Is it okay to change C1 to MLCC? If yes, what is the recommended value for C1?
Please check this issue. Thanks.
Best regards,
Chase
Dear Jacob,
Thank you for your support.
I clicked the link you mentioned, but I can see only the webpage below ;
Could you please check it again?
Best regards,
Chase
Ahh apologies Chase, looks like that other post is internal. I'll just copy-paste my response below. The original question was about replacing the 100uF capacitor with 4x 10uF MLCC:
Yes, replacing 1x bulk capacitor with 4x MLCC capacitors is fine, but the MLCC capacitance value will need to be higher to equate to the electrolytic capacitance after voltage derating.
The capacitance of a MLCC drops off significantly as the operating voltage approaches the rated voltage of the capacitor see the image below from DigiKey's VCC: Capacitance Change vs Voltage in Ceramic Capacitors, I've added a circle of the approximate capacitance change % it would be in your system for 24V VM at 35V MLCC. To have 40uF of actual capacitance you'll need nearly double the capacitors on the board, approximately 70uF of MLCC (7x 10uF) to functionally have 40uF.
I see you're going from 100uF capacitance to only 40uF capacitance. Depending on the load this is probably fine, but if you have existing boards with 100uF capacitors I recommend replacing that with a 40uF electrolytic cap first to confirm 40uF works. If you only want to use 4x 10uF I would test a 20uF electrolytic capacitor as the bulk capacitance and see if that is enough.
Regards,
Jacob
