High PWM Power Consumption

[andrew55529]

I have an LED connected, and I want to use PWM, but enabling it adds about 700 µA of passive current — both when the output is high and low. However, if I set the duty cycle equal to the period, the current consumption returns to normal.. Also, if I set the duty cycle to 0%, there is no additional current. What can i do to reduce this current?

[SwRa]

Hi Andrew, 

It should be possible to change the PWM frequency to use 400 Hz frequency. In the sample blinky_pwm, you can update the code where the PWM period is set, for example using the pwm_set_dt() function and using the PWM_HZ(x) macro, where x is your desired frequency: https://docs.nordicsemi.com/bundle/zephyr-apis-latest/page/group_pwm_interface.html#ga4a5edbee48c4a5706cf75524aef2364a:~:text=PWM_DT_SPEC_GET_OR-,%E2%97%86%C2%A0PWM_HZ,-%23define%20PWM_HZ .. 

Turning off logging when measuring current should also help in reducing the power consumption. The following blog explains what can be done to optimize the power consumption:  Optimizing Power on nRF52 Designs 

Regards,

Swathy