TPS62090 and TPS62143 - Is 2V prebias okay?

Original Question: TPS62090 and TPS62143 - Is 2V prebias okay? by Bryan McLaughlin

For the TPS62090, I understand there is about 200-ohm resistor to GND during disable. Is it safe for the device if the output will have a DC prebias of about 2V during the disable stage and upon enable stage when the target normal operation voltage is around 2.4V? Input is 3.3V.

Can you say the same for the TPS62143? Datasheet says it's good for prebias startup but I'm not sure if there's a limit.

 

Thanks,

Bryan, Sunnyvale Field Apps

 


Verified Answer: RE: TPS62090 and TPS62143 - Is 2V prebias okay? by Chris Glaser

Yes, pre-bias startup for these and other DCS-Control devices is ok as the devices do not sink current.  


Question: RE: TPS62090 and TPS62143 - Is 2V prebias okay? by Bryan McLaughlin

Just to make sure - you are saying the set output voltage neds to be greater than the prebias voltage?

For this application, Vout=2.4V and Vprebias=2.0V

 

Thanks,

Bryan


Question: RE: TPS62090 and TPS62143 - Is 2V prebias okay? by Chris Glaser

I'm not sure that a pre-bias above the setpoint makes sense.  But in this case, the device will also not sink current.  It will just sit there and not switch.