TPS65186 eval kit incorrect voltage

Alexander Roscoe

I am currently developing with the eval kit and my VPOS voltage is 16V while my VNEG voltage is -15V. These should be even +- 15V. I have tried adjusting the Trim to bring down VPOS but it has no effect. The trim only effects the VNEG value which is odd. Any idea on how to trim this out.

over 10 years ago

Matt Roberts over 10 years ago

TI__Prodigy 730 points

Hi Alex,

Can you try applying a small load to VPOS? Try connecting a resistor from VPOS to ground. Anything that will draw 200uA or more of current should do it.

See if that causes VPOS to come back to its regulated voltage.

Alexander Roscoe over 10 years ago in reply to Matt Roberts

Prodigy 140 points

That worked, it is reading 15v.

Alexander Roscoe over 10 years ago in reply to Alexander Roscoe

Prodigy 140 points

I am trying to power Vin with a 3.3v line and I am receiving at under voltage lock out. i2c is obviously working but the datasheet states that it should work 3-6 volts. I also see Vin rising hysteresis of 400mV. Does that mean the minimum for Vin is 3.4v to power on everything?

Matt Roberts over 10 years ago in reply to Alexander Roscoe

TI__Prodigy 730 points

alex,

What is the current rating of your supply? When the rails start up they can draw a large amount of current which can cause a transient droop in supply voltage that triggers a UVLO event.

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TPS65186 eval kit incorrect voltage