temperature and current consumption

[hunterliuyi]

Hi, all great guys,

We are using NRF51822 as the MCU,and met a very strange problem about the current consumption in our application. Normally,the lowest standby current of our application is about 50uA, but we found the lowest current of some PCBAs are higher than 100uA, and finally we found the strange problem, if we just heat the 51822 chip,the current will drop to 50uA, this will happen even only when we just put a finger on the chip to heat it,now the indoor temperature is about 15 degree C . I want to say that not all the chips have the same problem, but still this problem is very important, which will greatly affect the standby time of our product. We want to know that why this problem happened ,and how we can eleminate it whatever from the aspect of design or manufactering proceduce. Thanks a lot.

[Hung Bui]

Did you set the pin to output or input ? We need to clarify it was the issue with the GPIO pin. When in input mode, I don't think the pin would cause any current draw except if you enable GPIOTE PIN interrupt, but the current consumption should be nearly 1mA as the 16MHz will be kept running.

In your tests, how many chips have this problem and how many doesn't have ? Could you send the schematic, layout and a photo of the test board(s) ?

Could you reproduce the issue on a Nordic Development Kit ?