app_pwm high current consumption - SDK12

Question

Hi guys, 
 So as I'm migrating from SDK10 to SDK12 I've noted that the app_pwm module is consuming more power then expected while disabled ~300uA. After initialization, I do not see any increase in idle current, but once I start the PWM, after stopping the idle current increases to ~300uA. I used the following for my pwm_stop() 
 void pwm_stop()
{
app_pwm_disable( &PWM ); 
 nrf_drv_gpiote_out_task_disable( pin_1 );
nrf_drv_gpiote_out_task_disable( pin_2 );

app_pwm_uninit( &PWM );

nrf_gpio_cfg_output( pin_1 );
nrf_gpio_pin_clear( pin_1 );

nrf_gpio_cfg_output( pin_2 );
nrf_gpio_pin_clear( pin_2 );

pwm_active = false;	// pwm now disabled
 
 } 
 By all accounts this should properly disable the PWM and underlying GPIOTE modules. This worked fine on SDK10, but SDK12 has this issue. I've verified after a stop the the pins are indeeds Low, and I've also verified that the HFCLK is not running. Therefore this issue must lie in the PPI or GPIOTE tasking.

Stefan Birnir Sverrisson · Accepted Answer

Hi Dave 
 Tried this on my nRF51-DK and board and nRF5 SDK 12.1.0 and have the same result, current consumption is ~300uA after disabling app_pwm with either calling app_pwm_disable or app_pwm_uninit. You pointed out that this worked properly in SDK 10.0.0 so I compared the code in app_pwm_disable function and the only difference is that the pan73 workaround has been removed from SDK 12. So I added the following code to line 952 in app_pwm.c 
 pan73_workaround(p_instance->p_timer->p_reg, false);
 
 then the current consumption is normal. I am not sure at this point why the workaround was removed in SDK 12. I have reported the issue and will hopefully have an answer to that question soon.

app_pwm high current consumption - SDK12

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