TPS53015EVM-126: TPS53015EVM-126 SW node voltage

keisuke

Intellectual 475 points

Part Number: TPS53015EVM-126
Other Parts Discussed in Thread: TPS53015

Hi team.

I have a question about how to evalute the SW node voltage in TPS53015 EVM-126.

I measured the output voltage, SW node Voltage and Output current as follows condition.

-Vin=12V, Io=8A,

-Waveform channels

1ch:SW node voltage , 2ch:Output voltage, 4ch:Output current

-used the GND spring for passive probe(very short loop)

I found the undershoot of sw node voltage is below "-0.3V" and the period is over 10ns.

Does this affect the operation?

over 5 years ago

0 keisuke over 5 years ago

Intellectual 475 points

0 Mathew Jacob1 over 5 years ago

TI__Expert 5900 points

Hello,

Are you using a differential probe? That is the best to measure this. A passive probe does not cut it for this measurment. The points of the differential probe should be right across the SW pin to GND.

Regards,

Mathew

0 Mathew Jacob1 over 5 years ago in reply to keisuke

TI__Expert 5900 points

Also to answer your question. No this does not affect operation. Are you using EVM or your board. If it is your board please make sure input capacitor is right across the Vin pin and PGND.

Regards,
Mathew

0 keisuke over 5 years ago in reply to Mathew Jacob1

Intellectual 475 points

Hi Mathew
Thank you for your advice.

I measured the SW node voltage using a passive probe with GND spring.
so,I'll try to measure it using a differential probe.

Regards.
keisuke

0 keisuke over 5 years ago in reply to Mathew Jacob1

Intellectual 475 points

Thank you for your reply.
I used TPS53015 EVM.

Regards,
keisuke

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TPS53015EVM-126: TPS53015EVM-126 SW node voltage