TPS56C215: Feed Forward Cap, CFF

Sam Ting

Part Number: TPS56C215

Hi team,

Could you help confirm the below waveforms, can we modify the Cff to 3900pF? Because the load transient response with Cff= 220pF is too much ringing. Thanks!

Step current : 5~10A
High/Low period : 0.5ms
Slew rate : 2.5A/us

Best regards,
Sam Ting

over 4 years ago

0 Andrew Xiong over 4 years ago

TI__Expert 5470 points

Hi Sam,

Is the upper resistance of feedback divider smaller than the recommended value?

Could you provide the schematic? Since the choose of Cff is related with the output voltage, inductance, output capacitance, upper resistor of feedback divider and selected switching frequency.

Regards,

Andrew

0 Sam Ting over 4 years ago in reply to Andrew Xiong

TI__Expert 3710 points

Hi Andrew,

Thank you for your support! The problem was caused by the output capacitance being out of range.

Best regards,
Sam Ting

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TPS56C215: Feed Forward Cap, CFF