nRF51422 Current Consumption

[Dilip]

Hi,

We are currently working on nrf51422 bluetooth IC. we are facing a problem with the ic when we want to put it in sleep mode. without sdk when we call WFE() function it is going to sleep mode and taking 25uA but when we flash softdevice and call sd_power_system_off it is not going to sleep mode infact it is taking more current than usual.

Give me solutions to overcome this problem

[ketil]

Hi,

Which SoftDevice are you using? Are you running in debug mode? Which peripherals are you using?

It is difficult to give an exact answer without more information. If you search DevZone there are several questions regarding this problem that have already been answered:

SoftReset on sd_power_system_off();

nRF52 does not enter system off

BLE Advertising doesn't stop after sd_power_system_off()

problem about sd_power_system_off

Please check those cases and see if you can find a solution.

Ketil

[endnode]

Note that sd_power_system_off is something completely different then SYSTEM ON SLEEP mode which you normally achieve by running WFE/WFI instructions. This is trying to send SoC to POWER OFF mode which is deeper sleep. However because you most probably don't turn all necessary interfaces down the chip don't get to that state so power consumption which you observe is standard operation curve (SYSTEM ON state if you want). To send nRF5x SoC to SYSTEM ON SLEEP mode through Soft Device API you should use sd_app_evt_wait function call.

[Dilip]

Hi,

SDK 11 The softdevice we are using is S130 NO we are not running it in debug mode

We are using segger j link to communicate with the device

[Dilip]

Hi,

We have tried with this (sd_app_evt_wait) function also But we are not able to put it in sleep mode it is taking 700-800uA

[endnode]

You need to get current draw plots with sub-millisecond resolution to understand what is happening, these averaged values won't help you.