TPS54202: The PWM waveform at SW feet will wobble

user4413695

Part Number: TPS54202

Using the following circuit, Vin=20V and Vout= 3.6V.Load plus 0.5A, but the PWM waveform jitter in SW foot, how to solve？

over 5 years ago

0 Shawn Nie over 5 years ago

TI__Genius 10070 points

Hi,

R3 should be 10kohm, and could you please share the layout? If the layout is not good, it is easy to introduce noise.

Shawn

0 user4413695 over 5 years ago in reply to Shawn Nie

Prodigy 230 points

OK，enclose the layout in the question

0 Jason Wang (BSR-MV) over 5 years ago in reply to user4413695

TI__Genius 9550 points

hi,
Refer the datasheet page 1, Features mentions that "Frequency Spread Spectrum to Reduce EMI", so the "SW feet will wobble" is reasonable.
You can try TPS54202H which do not has "Frequency Spread Spectrum to Reduce EMI" and the SW will be stable.

0 user4413695 over 5 years ago in reply to Jason Wang (BSR-MV)

Prodigy 230 points

SO it does not affect normal use?right?

0 Shawn Nie over 5 years ago in reply to user4413695

TI__Genius 10070 points

Hi,

Yes, if you still worry about the stability, you could test the load transient and bode plot to double check it.

Shawn

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TPS54202: The PWM waveform at SW feet will wobble