Deep sleep current too high

[erniberni]

I have tested 4 Atom Lite with the deep-sleep sketch from the ESP32 library. I powered the modules directly with 3.3V and measured the power consumption in the 3.3V supply line. Nothing else was connected.
2 of these modules show a deep-sleep current of 40mA, which seems much too high. The other two modules have a deep-sleep current of 4mA, which is quite acceptable.
Do you have an explanation for this?

[JPFrancoia]

Hey, sorry to hijack your question. How did you power the board with 3.3V directly? I mean, to which pin did you input a 3.3V tension?

[erniberni]

There is one connector of the female connector strip labeled with 3V3.

[miag676]

Hi @erniberni, I'm thinking of using m5Atom Lite for my battery-powered project. I'm worried about the power consumption being too high, so I was wondering if you managed to find out how high is the power consumption in deep-sleep mode and why did you get different deep-sleep currents (40 mA and 4 mA)?

Best regards,
Mia

[erniberni]

Hi @miag676,
unfortunately, I could never find out the real cause. I suspect that a component, e.g. the voltage regulator, was damaged when I used the Lite with a very poor voltage source. But this is only a guess. The quiescent current of 4mA seems to be the correct result. This value would be realistic if the quiescent current of the USB-serial converter is not optimised. If you really need a very low quiescent current then use a ESP32 WROOM module without anything else connected and a very good LDO.

[linxcow]

I also have this M5 atom lite , i bought it for low power battery applications. ( product page : wearables?)
My deep sleep current is 9mA (rgb off) powered from 5v pin.

These are not recommended for long term battery applications unfortunately due to poor design choices ( high current LDO & RGB) battery will only last for a few days even when in deepsleep most of the time.

There is no deepsleep current mentioned on the product page.
Other esp32 boards can go as low as 40uA deepsleep

Unfortunately i found this github issue after i bought it.
Its a great module otherwise for other applications than low power.

[erniberni]

Thank you, I agree in total