BQ24072T: Capacitance on Input

MB9265

Part Number: BQ24072T

The datasheet for the BQ24072T states that "the input capacitance to the device must be selected small enough to prevent a violation (<10 μF), as this current is not limited."

Would a power adapter with a large capacitance on the output cause issues?

over 2 years ago

0 Anthony P Pham over 2 years ago

TI__Mastermind 23200 points

Hi,

If the power adapter's capacitor is closer to the device, it can as it would surely exceed the 10uF hard start limit mentioned by the USB-IF compliance specification.

I notice this is your second question regarding the capacitances on the device, is there a specific concern or reason? I may be able to expand further or can provide more on the capacitance choice if a reason is provided.

Best Regards,

Anthony Pham

0 MB9265 over 2 years ago in reply to Anthony P Pham

Prodigy 60 points

We have been seeing current spikes on the input line of the power adapter that are potentially causing the output capacitor on the power adapter to fail. It is a 470uF electrolyte cap that is not close to the device.

0 Anthony P Pham over 2 years ago in reply to MB9265

TI__Mastermind 23200 points

Hi,

This shouldn't affect the device as the spikes are most likely charging the capacitor. If the current is going to the device, the input limit should trigger in about1 ms based on my tests.

Best Regards,

Anthony Pham

Power management

Power management forum

BQ24072T: Capacitance on Input