Additional capacitance on output of TPS82671

Antenna_Head

Other Parts Discussed in Thread: TPS82671, TPS82671EVM-646

Team-

We have the following query regarding the TPS82671 and it's tolerance of additional output capacitance:

--------

There are minimum capacitance requirements at the load that I can not control.

Does the TPS82671 have maximum output capacitance constraints? The spec states a maximum of 7uF of external capacitance under PWM mode.

Is this a firm requirement? What if I have a POSCAP on the output, or the caps are isolated with a ferrite bead with DCR = 10m for instance?

--------

Are there any tricks (beads, etc...) that we can use to allow additional capacitance to be added to the output of the TPS82671 w/o making it unstable?

Best regards, S. Dunbar, AFA Colorado

over 14 years ago

0 Antenna_Head over 14 years ago

TI__Genius 12800 points

Team-

This is a ping- please respond to this thread as soon as possible.

Best regards, S. Dunbar

0 Matthew Day over 14 years ago in reply to Antenna_Head

TI__Mastermind 36110 points

We probably missed answering the origial post because the subject line didn't start with the part number first. Sorry about that.

You can not add greater than 7uF of additional output ceramic output capacitance to the TPS82671 in PWM mode. Additional ceramic capacitance can cause the converter to go unstable. It might be possible to add additional capacitance that has significant ESR as long as the ESR zero is less than 6kHz. We'll try this and let you know the results of testing.