nRF52832 High Power consumption on custom design?

[SamB]

Dear Support Team,

We are working on nRF52832 based custom design. We had interfaced 3 different sensors (i.e. one with SPI and 2 with I2C bus mode) and sending continuous the data out over BLE UART  in BLE Peripheral mode. The total data output is around 1064 bytes/sec.

Following are the current details of our custom design,

- Our device works on 3V (CR2477/1000mAh) coin cell battery. nRF52832 supply voltage is 3.3V and internal DC-DC regulator is ON. We are using internal RC LF clock and Radio TX power is set to -40dbm. Serial Uart is also disabled.

Currently we are facing major issue with power consumption. We are using the nRF Power Profile Kit (PPK) to measure the current consumption. The PPK shows average power consumption around 2-3mA  and Max around 15-19mA. As we are using higher capacity battery (CR2477, 3V/1000mAh) for longer battery backup, but battery could not last more that 3days. We not able to understand that whether the PPK measurement are correct or not. Herewith sharing the PPK screenshot for reference. 

Request to look in it and support us.

Thank you.

 

[haakonsh]

Are you measuring the current consumption of the PCA10040DK or a custom board?

The first thing I do when I want to measure the current of a faulty device with an nRF52 and multiple peripheral sensors or other circuitry is to isolate the power supply of the nRF52 from the power supply of the rest of the circuit. That way I can measure the current consumption of the nRF52 while the device is operating as intended and compare it to the total current consumption. This will tell me whether the abnormal current consumption is present in the nRF52, the rest of the device, or both. 

Isolating the erroneous current consumption is key in finding the root cause. If the current consumption of the nRF52 is not at fault, or not entirely at fault, I would continue isolating the power supply of the sensor's, one-by-one, followed by other circuitry until you find something interresting. 

[SamB]

Thanks for reply.

We are measuring the current consumption of the custom board which includes the NRf52832 and all 3 sensors on PCB. But what about the Max current consumption around 15-20mA as we are observing in PPK.

The function of our device is such that nRf52 receives data from all sensors and sends it out over BLE UART service continuously. 

Request you to guide us for to lower the current consumption.