TPS65273V: TPS65273VRHHT Channel 2 Power Down

Affaan Mohammed

Part Number: TPS65273V

Hey,

I am using the TPS65273VRHHT voltage regulator. When I power down the regulator with either setting the enable to low or disabling the output via writing to a register I see a weird RC discharge curve.

I was wondering if this is normal behavior or a design problem on my end and how I can fix this. I setup the eval board for this regulator and saw the same behavior as channel 2(my board) on both channel 1 and 2 of eval

board.

Channel 1 (1.8V)

Channel 2 (1.05V)

Here is a picture of our setup

over 1 year ago

0 Calan Elaya over 1 year ago

TI__Expert 5235 points

Hello,

An answer will be posted early next week.

Best,

Calan

0 Lucia Gao over 1 year ago

TI__Mastermind 19610 points

Hi,

Thanks for reaching out. Could you please kindly let us know what is the load current of Buck2? Is it light load or almost no loading? If yes, the output voltage will only discharge with Cout that's the reason why you see Vout power off waveform showing like "RC" as you described.

Thanks! Kindly let us know for anything unclear.

BRs

Lucia

0 Affaan Mohammed over 1 year ago in reply to Lucia Gao

Prodigy 10 points

Hey Lucia,

That makes sense, do you have any design recommendations on how to fix this?

Thanks

Affaan

0 Lucia Gao over 1 year ago in reply to Affaan Mohammed

TI__Mastermind 19610 points

Hi Affaan,

What is your actual loading? You can either add some dummy load or add discharge circuit if you don't want long Vout power down time. Thanks!

BRs

Lucia

0 Affaan Mohammed over 1 year ago in reply to Lucia Gao

Prodigy 10 points

The load on that rail should be less than 500mA

Thanks

Affaan

+1 Lucia Gao over 1 year ago in reply to Affaan Mohammed

TI__Mastermind 19610 points

Hi Affaan,

Thanks for your feedback. Kindly let us know any further support need.

BRs

Lucia

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TPS65273V: TPS65273VRHHT Channel 2 Power Down