TPS51220A: The PWM phase waveform on the DCAP mode for the TPS51220A design

Alec Chen

Part Number: TPS51220A

Dear Sir,

Our customer have designed TPS51220A and they current using the DCAP mode. However, the phase waveform(the PWM waveform after skip mode) didn't look like the DCAP mode to us. and we use the same setting on the TPS51220A EVM(DCAP, SKIP mode).The waveform looks the same.the waveform is in the attachment. Could you kindly advise us why the waveform didn't look like the DCAP mode?Thanks in advance

over 5 years ago

0 Edwin Zang over 5 years ago

TI__Expert 6425 points

Hi Alec,

The DCAP mode that TPS51220A adopt is different with typical DCAP mode. TPS51220A use constant frequency DCAP mode, not constant on time. The typical DCP mode is constant on time DCAP mode.

BRs.

Edwin.

0 Alec Chen over 5 years ago in reply to Edwin Zang

Intellectual 730 points

Hi Edwin,

Many thanks for the reply. About the constant frequency DCAP mode, We are not familar about this kind of DCAP mode. What is the differences form the typtical DCAP or noramly valtage mode, current mode?Could you provide some data about this for us to staudy it? Also. for TI DCAP mode. there is no need to loop gain measurement. Is the constant frequency DCAP mode also no need to measeure to loop gian to make sure the gian loop's stability?please kindly give us some advises. thanks in advacne

BRs

Alec

0 Edwin Zang over 5 years ago in reply to Alec Chen

TI__Expert 6425 points

Hi Alec,

please contact me by Email. my email is edwin-zang@ti.com.

BRs

Edwin.

0 Alec Chen over 5 years ago in reply to Edwin Zang

Intellectual 730 points

Hi, Edwin,

I have sent a mail to you eimail last Friday, but haven't hear from you yet. Could you kinldy give us some udpate?Our cusotmer is pushing us for thie question, please kindlly hlep us with that. thanks in advance

BRs

Alec

0 Edwin Zang over 5 years ago in reply to Alec Chen

TI__Expert 6425 points

Hi Alec,
As we talked on the phone, please double check. if you have any question, please send me email.
Edwin.

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TPS51220A: The PWM phase waveform on the DCAP mode for the TPS51220A design