TPS548A20: FCCM Load Transient

Shuji Ishiwata

Part Number: TPS548A20

Tool/software:

Hi All,

I have a question about the Load Transient of the TPS548A20.
Even in FCCM, does the switching period change temporarily at the moment the load changes?

When I checked the data sheet, it looks like switching is temporarily skipped even in FCCM.

Best Regards,
Ishiwata

3 months ago

+1 Tahar Allag 3 months ago

TI__Mastermind 32370 points

Hello Ishiwata,

That is an expected behavior for Constant on time controllers. this device is DCAP3 and the control loop will reduce the switching frequency or increase the switching frequency base on the load the VOUT/FB voltage. that is how the controller maintain a good transient response when comparing to fixed frequency controllers.

https://www.ti.com/document-viewer/lit/html/SSZTCQ9

Thanks

Tahar