TPS780: TPS78001 overshooting when Enable pin from low to high

Kritank Kalyan

Prodigy 130 points

Part Number: TPS780

Tool/software:

Why this overshoot is happening and how to tame it?

10 months ago

0 Stephen Ziel 10 months ago

TI__Mastermind 37075 points

Hi Kritank,

Can you please provide a schematic? Can you show Vin, Ven and Vout on the oscilloscope?

Thanks,

Stephen

0 Kritank Kalyan 10 months ago in reply to Stephen Ziel

Prodigy 130 points

Orange arrows are the oscilloscope probes Vout is around 5.12V and Vin and Ven is 6V.

0 Stephen Ziel 10 months ago in reply to Kritank Kalyan

TI__Mastermind 37075 points

Hi Kritank,

Can you plot Vin, Ven and Vout on the oscilloscope at the same time and let me see the results?

Thanks,

Stephen

0 Kritank Kalyan 10 months ago in reply to Stephen Ziel

Prodigy 130 points

I'm not sure, in the mean time could you confirm the overshoot %age at max recommended regulated voltage at max Vin, while you high Ven low to high?

0 Stephen Ziel 10 months ago in reply to Kritank Kalyan

TI__Mastermind 37075 points

Hi Kritank,

If the input voltage is drooping while the output voltage is turning on, then the LDO will turn on while in dropout and may overshoot. We won't know unless the measurements are taken and we can see Vin, Vout and Ven on the oscilloscope.

Thanks,

Stephen

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TPS780: TPS78001 overshooting when Enable pin from low to high