I’m currently making some measurements with a power analyzer on both, our own hardware design with the nRF52840 (Samples B) and the nRF52840 Preview Dev Kit.
I took the template project and added the following lines in the main:
int main(void)
{
int i;
// Init Port 0
for(i=0 ; i<48 ; i++)
{
nrf_gpio_cfg_input( NRF_GPIO_PIN_MAP(0 , i) , NRF_GPIO_PIN_PULLDOWN);
}
// Init Port 1
for(i=0 ; i<16 ; i++)
{
nrf_gpio_cfg_input( NRF_GPIO_PIN_MAP(1 , i) , NRF_GPIO_PIN_PULLDOWN);
}
// Enter SYSTEM OFF Mode
NRF_POWER->SYSTEMOFF =1;
while(true){__WFE();}
}
PDK
For the measurements with the PDK, I supply the circuit through P21 (External supply) with SW10=OFF and SW6= nRF Only.
With a supply voltage of 3.3V, I measure a current of 8.7 uA.
With a supply voltage of 1.8V, I measure a current of 6.6 uA.
The chapter 16.10.2 in the Specification v0.5.1 says that the current should be 0.7 uA. (With some additional current drawn by RAM). So, my measurements are too high.
1. Am I doing something wrong (e.g. forget to turn off some internal peripherals) or do I misinterpret the specifications?
Own hardware design
When I measure the power consumption of our own design, the current is even higher although nothing is connected to the nRF52840 nor is anything else powered on the board. It is only the reference circuitry running in configuration 3 .
With a supply voltage of 3.3V, I measure a current of 53 uA.
With a supply voltage of 1.8V, I measure a current of 31 uA.
2. Have you already measured the current consumption with samples B? Should it also be around 0.7 uA? If so, I appreciate any pointers. Apart from that, I know that support for the own hardware is rather difficult.
Thanks in advance 
