TPS54531

vanu

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Hi,

I need help to calculate the compensation components for TPS54531.

It was difficult for me to understand how to calculate R3 (special the terms Gpwrstg and Gmea in equation 17 of datasheet ) and also need help in choosing the crossover frequency.

My design details are: output inductor = 5.6uH: output capacitor = 22uFx 2 caps; output voltage = 12V; input voltage = 15V; output ripple expected = 30mV and output current = 3A.

Thanks

over 9 years ago

0 JohnTucker over 9 years ago

TI__Guru**** 191445 points

That datasheet procedure is relatively straight forward. However it is based on a pspice average model that apparently was never released. I would probably recommend that you try webench automated design tool to calculate your component values. You can modify the filter compenent values to suit your needs and use the re-comp function to optimize the compensation. I usually try for Fco between 20 - 70 kHz.

0 JohnTucker over 9 years ago in reply to JohnTucker

TI__Guru**** 191445 points

I ran a quick check in webench. For 5.6 uH and 2 x 22uF output filter, WB calculates Rcomp = 31.6k, Cseries = 1500pF, Cparallel = 25 pF.
Fco = 28.48 kHz, PM = 56.29 degrees. Seems reasonable to me.

0 vanu over 9 years ago in reply to JohnTucker

Prodigy 40 points

Thanks John

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TPS54531