TPS92515HV-Q1: Output current overshoot and undershoot

Zhang Jason

Part Number: TPS92515HV-Q1

Hello,
It is found that the there is a significant overshoot and undershoot on output current when output LED voltage decrease or increase suddenly.
Attached waveform shows that the output current increase from 1.22A to 1.46A when output voltage decreases about 2.8V, and output current decrease from 1.22A to 780mA when output voltage increase about 2.8V.
So is there any proposal to decrease this overshoot and undershoot at ouput voltage transient?

over 2 years ago

0 Xiaoguang over 2 years ago

TI__Genius 17720 points

May i know what the load is and how you set up the test? How to achieve output LED voltage decrease or increase suddenly? thanks.

0 Xiaoguang over 2 years ago in reply to Xiaoguang

TI__Genius 17720 points

You may try reducing output capacitor.

0 Zhang Jason over 2 years ago in reply to Xiaoguang

Prodigy 175 points

The load is 12pcs LED and controlled by Matrix LED Controller(like TPS92662). The overshoot and undershoot occurs at the moment when the bypass LED switches in the controller turns on and turns off.

0 Zhang Jason over 2 years ago in reply to Xiaoguang

Prodigy 175 points

It is found that the improvement is limited(overshoot only reduces from ~1.46A to 1.38A) when output capacitor is reduced from 2uF to 1uF.
So is there any other solution?

0 Xiaoguang over 2 years ago in reply to Zhang Jason

TI__Genius 17720 points

You can even remove output capacitor, while it increases output ripple current.

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TPS92515HV-Q1: Output current overshoot and undershoot