Q: TPS62170 -- LC filter (SLVA463) by 4713

  I would like to ask about the appl note (SLVA463) to choose the output filter for TPS61270.

  Is not the frequency values described in the table-1the cut-off or corner frequency as equation (1) in page2 of the appl note ?

  I'm thinking that these frequency values in the table-1 are the points of  crossing 0dB for the control loop response with each L and C combination. Is my thinking correct ?


A: Re: TPS62170 Appl note question. by 317711

your understanding is right. The frequencies shown in the table are effective corner frequencies. The distance to frequencies caused by non-dominat poles is a degree of stability. If the corner frequency comes close, parameter variations may lead to unstabilities. Therefore you can find LC combinations that work in one application and dangerous in another.