TPS610981: High quiescent current draw

Phil Grant

Part Number: TPS610981

I have created a PCB using the TPS610981 and the reference design from the datasheet and I'm seeing a high quiescent current (15 - 20uA) with no load connected.

Has anyone got any suggestions as to why it's so high?

Thanks

over 1 year ago

0 Stefan Schauer over 1 year ago

TI__Guru 58641 points

Hi Phil,

thank you for using the E2E forum.
Due to a public holiday this Thursday and Friday the expert of this device is out of office.
Please expect a reply beginning of next week.

Best regards,
Stefan

0 Phil Grant over 1 year ago in reply to Stefan Schauer

Prodigy 40 points

OK Stefan,

Thanks for letting me know.

Phil

0 Nini Zhong over 1 year ago in reply to Phil Grant

TI__Genius 13635 points

Hi Stefan,

Thanks for helping to answer the question.

Hi Phil,

The quiescent current is under no switching condition. I guess the device is switching and the current you test is not IQ. To test the IQ, Vout should be forced higher than target then no switching happens. Thus the 20uA with swicthing consumption is reasonable.

0 Phil Grant over 1 year ago in reply to Nini Zhong

Prodigy 40 points

Hi Nini,

Thanks for the reply.

So if I'm powering an ESP8266, in deep sleep mode (~20uA) and supplying from two AA batteries in series (~3V) what is the expected current draw of the Boost converter circuit?

0 Nini Zhong over 1 year ago in reply to Phil Grant

TI__Genius 13635 points

Hi Phil,

We haven't get the data yet. But according to the simulation, it might be 60~100uA.

0 Phil Grant over 1 year ago in reply to Nini Zhong

Prodigy 40 points

OK, Thanks for the info.

One thing I've noticed is that compared to an MT3608 IC it is much more noisy even though it's average current consumption is less, can this noise be reduced by altering the components?

The circuit is as above in OP with MODE grounded and R5 removed.

Screengrabs of currents using Nordic PPK2

MT3608

TPS610981

0 Nini Zhong over 1 year ago in reply to Phil Grant

TI__Genius 13635 points

Hi Phil,

Could you add the Cout at the Vsub pin, supposing you are using the Vsub pin, is that right?

0 Phil Grant over 1 year ago in reply to Nini Zhong

Prodigy 40 points

I'm not using the Vsub pin, I'm only using the Vmain pin at the moment

0 Nini Zhong over 1 year ago in reply to Phil Grant

TI__Genius 13635 points

But if you want low noise why don/t choose the LDO output Vsub?

0 Phil Grant over 1 year ago in reply to Nini Zhong

Prodigy 40 points

OK I can give it a try, originally I was going to supply a slave circuit on Vsub but we found that the quiescent for the slave circuitry was negligible so we just powered everything of Vmain.

0 Nini Zhong over 1 year ago in reply to Phil Grant

TI__Genius 13635 points

Hi Phil,

wait for your feedback.

0 Phil Grant over 1 year ago in reply to Nini Zhong

Prodigy 40 points

OK, The noise on the supply line is present on both Vmain and Vsub but I'm not too botherd about the voltage noise on the supply as I suppose that's inherent in the design.

My original question was to do with the current measurement taken with a PPK2, when compared with another type of step up converter, there is much more noise in the current measurement of the input which leads to a higher average Quiescent current during the ESP12 deepsleep.

I did find another issue with the circuit that enabled me to get the average current down to an acceptable level so I willl consider my issue resolved but I do tink the quiescent would be lower if the noise was reduced but accept this may not be possible.

Thanks for you support.

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TPS610981: High quiescent current draw