TPS650231: LDO Sink/leakage

Jeff Coletti

Part Number: TPS650231

Hi Support team,

My customer is using TPS650231 in a very high volume design and are seeing the LDO outputs rise from 1.8v to 2.0v. Is there any leakage where in a no load condition the LDO would rise on its own? If there is reverse leakage on the device the ldo is supplying (from another source,) such that it is back feeding the LDO, could the LDO sink this current?

Regards

Jeff Coletti

over 6 years ago

0 Brian Berner over 6 years ago

TI__Mastermind 30280 points

Jeff,

Please share a schematic of the design.

What is the capacitance on the LDO1 and LDO2 outputs?

0 Jeff Coletti over 6 years ago in reply to Brian Berner

TI__Expert 8735 points

Hi Brian

the have a total of 10uf ceramic on the output. Will ask for a schematic.

Thanks
Jeff

0 Brian Berner over 6 years ago in reply to Jeff Coletti

TI__Mastermind 30280 points

Jeff,

Leakage typically comes from the processor (or MCU or FPGA) that is being powered.
It often takes a long time to debug if we start by looking at the PMIC.

My suggestion is to remove LDO1 and LDO2 outputs from their load (cut the trace) and see if the output voltage still rises.
If the LDO goes to the target voltage and does not go above the target, the leakage is coming from the processor (or MCU or FPGA).

0 Brian Berner over 6 years ago in reply to Brian Berner

TI__Mastermind 30280 points

Jeff,

Since you have not replied for a couple weeks, I will mark this thread as Closed. If you still need technical assistance, please reply with more info to help us solve your issue. If your issue is resolved, please explain the root cause of the issue and mark the question as answered.

Thanks,
Brian

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TPS650231: LDO Sink/leakage