TPS62136: SS/TR tracking offset

Oba

Genius 17355 points

Part Number: TPS62136

Hello,

I have a question about TPS62136 SR/TRK function.

Now I’m trying forced discharge by changing SS/TR from high to low(=0V).

But VOUT doesn’t go to 0V and continue to output about 0.3V even if SS/TR=0V.

And it looks to be regulated to 0.3V.

I think this behavior is defined as ISS/TR Tracking offset like the below table in the datasheet.

My question is that is there any way to discharge completely, meaning VOUT=0V, by SS/TRK function?

Also could you tell me where does this offset come from?

Regards,

Oba

over 7 years ago

0 Chris Glaser over 7 years ago

TI__Guru**** 150950 points

Hi Oba,

Are you operating in forced PWM mode or PFM mode? Per the D/S, you need to be in forced PWM mode to sink a voltage.

At 0V, you are right at the negative rail for all of the op amps inside. Non-linearities exist in any op amp as you get close to the voltage rails with the common mode input level.

To discharge Vout fully, you can disable the IC.

0 Oba over 7 years ago in reply to Chris Glaser

TI__Genius 17355 points

Hello,

Thanks for your reply. I uses forced PWM mode.

Regards,
Oba

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TPS62136: SS/TR tracking offset