TPS62867: Output discharge when no input.

Kengo.Y

Part Number: TPS62867

Hi team,

I'd like to know if the output discharge function works when VIN(=EN) is 0V.
Is it possible to use it under this condition?

And, if you have any waveform that can help, could you please share me?

Sincerely.
Kengo.

over 2 years ago

+1 Dorian Brillet de Cande over 2 years ago

TI__Genius 14876 points

Hello Kengo,

When device is in Shutdown mode and a sufficient Voltage applied at the input Vin∈[2.4V ; 5.5V], an internal switch smoothly discharges the output through the VOS pin in shutdown mode. This functionality is described in Topic 8.4.1 (Enable and Disable).

You can observe the waveform you are referring to if you have a look at the Figure 9-19 (Startup with No-Load) in the datasheet.

Let me know if you have any further questions.

Thanks a lot!

Regards,
Dorian

0 Kengo.Y over 2 years ago in reply to Dorian Brillet de Cande

Guru 10735 points

Hi Dorian,

Thank you for your reply.

I understood that 2.4V~5V is required for Vin to use the discharge function.
If I want to discharge the output load when Vin is 0V, what kind of circuit do you recommend?

Sincerely.
Kengo.

+1 Dorian Brillet de Cande over 2 years ago in reply to Kengo.Y

TI__Genius 14876 points

Hello Kengo,

Is this scenario realistic in your Application ? Are you referring to testing of a board where you would need to apply a VOUT without a VIN, basically bypassing the Step-down Converter ?

Here is a good paper on the topic: Testing tips for applying external power to supply outputs without an input voltage

If not you could still use a dummy load at the output to force the discharges of the output stage.

Let me know.

Thanks a lot!

Regards,
Dorian

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TPS62867: Output discharge when no input.