Excluding 32MHz crystal and 32KHz crystal from nRF52 custom board.

[Swapnil]

Hello,

I am developing a custom board using nRF52. In my previous custom board, the total current consumption is 15mA with DCDC regulator enabled. I want to reduce this current consumption. Is it possible to exclude 32MHz external crystal, since it is just used to control 64MHz crystal oscillator and I am not using it also. Also I have the same idea of removing 32KHz external crystal for reducing total current consumption.

Is it possible to do in that way ?

What other ways are there for reducing overall current consumption ?

[Keton]

15mA is a lot for nRF5x application. Either you're using additional components that are power hungry or there's much to optimize in your code. Cutting out crystals most likely won't help you. They aren't running when they're not needed and I can easily achieve 40 uA in BLE connection with lots of processing going on and both crystals used.

[Swapnil]

I am using nRF52 for reading data from MPU9250 using bluetooth application in mobile. And complete current consumption is 15mA.

[Keton]

MPU9250 has typical power consumption of about 4mA. TWI master + connection application should draw no more than 1mA without too much power management. Optimized it should go down to about 0.5mA or even lower depending on how long TWI peripheral is active. So check your code.

[RK]

well if you're using bluetooth then no you can't remove the 32MHz crystal because it's required for radio operation. You can remove the 32kHz crystal if you want. However as others have pointed out, your current consumption is higher than it should be for the peripherals you're using and so you are most likely looking in the wrong place.