TPS61042: Can We Add 220pF or 1000pF Cap at LED Output of the TPS61042?

Wayne Chen (Audio AE)

Part Number: TPS61042

Hi Sirs,

As title, can we add 220pF or 1000pF capacitance at LED output pin of the TPS61042 as a solution to reduce EMI?

Thanks a lot,

Wayne Chen
03/19/2020

over 5 years ago

0 Sean Zhou over 5 years ago

TI__Mastermind 22745 points

Hi Wayne,

Add a small to SW pin may help a lot than add a small-cap to the output part.

Sean

0 Wayne Chen (Audio AE) over 5 years ago in reply to Sean Zhou

TI__Genius 15950 points

Thanks a lot, Sean. Is there performance or reliability impact if we connect 220pF or 1000pF cap on LED pin?...Wayne Chen

0 Sean Zhou over 5 years ago in reply to Wayne Chen (Audio AE)

TI__Mastermind 22745 points

Hi Wayne,

If you only use a 220pF or 1000pF that maybe cause the loop not very stable, but if you have another output capacitors at the output side, adding this small caps doesn't have many effects on the reliability.

Sean

0 Wayne Chen (Audio AE) over 5 years ago in reply to Sean Zhou

TI__Genius 15950 points

Hi Sean,

What is our recommended capacitance range if we add a cap on SW node for EMI?

Thanks a lot

Wayne Chen
03/20/2020

0 Sean Zhou over 5 years ago in reply to Wayne Chen (Audio AE)

TI__Mastermind 22745 points

Hi Wayne,

That really depends on the test result, you can try with the 10ohm and 33pFserially connected first and adjust that based on the test results.

Sean

Power management

Power management forum

TPS61042: Can We Add 220pF or 1000pF Cap at LED Output of the TPS61042?