Power consumption question

[Jay]

Hi,

I noticed that my current NRF52 based prototype is consuming 4.5mA as soon as I enable the BLE functionality, when its off its only 1.6mA

I send the chip to a sleep in he main loop whenever it does not have anything to do but this does not improve on the power consumtopn with ehabled BLE.

The high power consumption starts as soon as the BLE functionality gets enabled even when no data are sent or recived.

If I'm reading the datasheet correctly this is much to high.

Any ideas what may be the rason, any often done mistakes i should check for first?

Cheers

[Jay]

its a custom board, it also has a ICM20948 gyro/accel sensor and a flash memory chip. but when i disable ble the power consumption drops to 1.6mA thatsstill a lo but clearly the most part before was ble

[hmolesworth]

If using the Nordic Serial Port profile note that this enables the serial hardware USART on the (eg) nRF52832. Where this USART is not required, turning the USART off after pushing out some startup messages reduces power consumption by around 1mA (ie. a lot). Use app_uart_close() to turn off. I see around 1.5mA static consumption while connected over BLE when running multiple peripherals both on-chip and off-chip, but it took significant effort to get there.

[hmolesworth]

I wonder what supply voltage you are using? 1.9 volts consumes significantly less power than 3 volts, and a regulator such as the TPS62732 lets you put it into Bypass mode when asleep (with virtually no Iq) to achieve sub-2uA consumption with RTC running so Off mode is not mandatory.

[haakonsh]

Hey Jay, I need you to electrically isolate the nRF52 from the rest of the circuit and re-run your measurements. We need to determine if the current consumption is due to the nRF52 or external circuitry before we proceed. I have experienced painful debugging sessions where I ultimately traced an increased current consumption to a faulty MOSTFET on a custom board. 

I usually start by cutting traces to the most suspecting circuit. In this case it's the external IC.
You might want to write some dummy code for the interaction between the nRF52 and the external circuits, so your application wont crash.