about current consumption at 1.8V

[Qinghua]

Hi, Schematic and Code As shown above, VCC 3V (DEC2 and VCC open) current is only 3.8uA, but VCC 1.8V (DEC2 and VCC short circuit) current exceeds 1mA, what am I mistaken? Would like to hear any suggestions about Low voltage mode, thank you!

[Roger Clark]

No.

nRF5x hardware will operate at 1.8V, and the software is voltage independent.

See

www.nordicsemi.com/.../nRF52832

or

www.nordicsemi.com/.../nRF51822

[Qinghua]

Thanks for your reply. But I have a question: when I used 3.3V power supply(DEC2 connected capacitor to the ground), the current is below 30ua. But when I used 1.8V power supply(DEC2 connected 1.8V), the current is always higher than 1mA. I wonder if I overlooked the details? Regarding Low voltage mode, is there any more detailed information?

[Roger Clark]

OK. So this question has nothing to do with ble_app_uart in particular

This seems to be question about current consumption at 1.8V vs 3.3V ?

I think you need to update your question title to reflect the actual question

[Sigurd]

Hi,

Please make sure you do a power-reset before starting any measurement. After programming the chip the nRF51 will stay in debug mode which consumes ~1mA

[Sigurd]

Try __WFE(); __SEV(); __WFE(); , and then do a power-reset.

If that does not help, then it could be an issue with debug mode. See this post. Regarding your layout:

We recommend to add a small resistor on the SWDCLK line to make it more robust [See reference circuitry in nRF51822 Product specification v3.3. The resistor should be as small as possible, yet still make it possible to program the chip. We have recommended 1kohm.