TPS7A05: No load(< 4 uA) behavior

Jehangir Parvereshi

Intellectual 510 points

Part Number: TPS7A05

Hi ,

We have a very light load on the LDO ~ 4uA. The data-sheet states minimum 10uA for proper rgulation.

Read in some literature that LDOs can go unstable under no load or loads below the specified minimum.

Is there any data that shows the LDO behavior at very light loads. We have a 1uF at the LDO output.

Thanks,

over 5 years ago

0 Stephen Ziel over 5 years ago

TI__Mastermind 37025 points

Hi JP,

Let me look into this. It might take me through the weekend to get some clarification.
The datasheet states that 10uA load is required for output voltage accuracy.
It does not say it is for stability.

Normally this wording is for adjustable regulators, and 50x or 100x of the feedback bias current is needed to swamp out the effects of the bias current.
So the feedback resistors would be "small" enough such that 10uA of loading would occur.

Right now I'm not ready to say that there is a stability issue.
Give me some time to review this and get back to you.

Thanks,

- Stephen

0 Stephen Ziel over 5 years ago in reply to Stephen Ziel

TI__Mastermind 37025 points

Hi JP,

Please see the following E2E forum thread.
This discusses the same note in the datasheet.

Output error was observed at very light loads, < 2uA.
The increase in output voltage was about 5% above the nominal setpoint at these very light loads.

https://e2e.ti.com/support/power-management/f/196/t/744220?tisearch=e2e-sitesearch&keymatch=TPS7A05

Thanks,

- Stephen

0 Jehangir Parvereshi over 5 years ago in reply to Stephen Ziel

Intellectual 510 points

Hi Stephen:

This addresses my concern.

Thanks.

Power management

Power management forum

TPS7A05: No load(< 4 uA) behavior