SMPS discharge path for output capacitor during power off

prachi panse1

Other Parts Discussed in Thread: TPS54418, LMZ31707, TPS54620

Hi,

I have a question regarding the output capacitor discharge for LMZ31707, TPS54620 and TPS54418 SMPS devices:

When the input to the SMPS is turned off, the charge at the output capacitor of the SMPS will discharge. Does the SMPS provide an internal path for this discharge or does it happen through the load alone?

Regards,

Prachi

over 9 years ago

0 prachi panse1 over 9 years ago

Intellectual 980 points

Hi,

Can you please update me on the query?

Regards,

Prachi

0 Anston Lobo over 9 years ago

TI__Genius 16025 points

Prachi,

I can only comment on the LMZ31707, for info on the other parts, please post to the Non-isolated forum.

On most buck regulators, if the output voltage is higher than the input voltage, It will forward bias the internal high side body diode and conduct through. To prevent this, It is recommended to place a diode on the input of the regulator to prevent a backward conduction path through the device.

Thanks,
Anston

0 prachi panse1 over 9 years ago in reply to Anston Lobo

Intellectual 980 points

Thanks Anston. This has answered my question.

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SMPS discharge path for output capacitor during power off