nRF5340-DK Low Power Configuration Issues

Hi,

I am performing some evaluation on the low power capabilities of the nRF5340 using the DK and the PPK v1.

I have written a really basic BLE Peripheral Application based loosely around the peripheral_lbs sample code as I want to test with a button handler eventually.

The problem I have is that after considerable configuration, I can only get the current floor down to ~200uA with an average current of ~215uA with a 1.2 second advertising interval. I've seen a lot of people on here talk about seeing much, much lower currents so wondered is there a configuration that I am missing perhaps?

I have been reading the documents and a few threads on here to understand how to configure the device and I have done the following.

1. My main application, running on the NS partition, has been configured as follows:
   
   

   CONFIG_NCS_SAMPLES_DEFAULTS=y
   
   CONFIG_BT=y
   CONFIG_BT_PERIPHERAL=y
   CONFIG_BT_DEVICE_NAME="MH_TEST"
   
   # Enable the LBS service
   CONFIG_BT_LBS=y
   CONFIG_BT_LBS_POLL_BUTTON=y
   CONFIG_DK_LIBRARY=y
   
   # Drivers and peripherals
   CONFIG_I2C=n
   CONFIG_WATCHDOG=n
   CONFIG_GPIO=n
   CONFIG_PINMUX=n
   CONFIG_SPI=n
   CONFIG_SERIAL=n
   
   # Power management
   CONFIG_DEVICE_POWER_MANAGEMENT=y
   CONFIG_PM=y
   
   # Interrupts
   CONFIG_DYNAMIC_INTERRUPTS=n
   CONFIG_IRQ_OFFLOAD=n
   
   # Memory protection
   CONFIG_THREAD_STACK_INFO=n
   CONFIG_THREAD_CUSTOM_DATA=n
   CONFIG_FPU=n
   
   # Boot
   CONFIG_BOOT_BANNER=n
   CONFIG_BOOT_DELAY=0
   
   # Console
   CONFIG_CONSOLE=n
   CONFIG_UART_CONSOLE=n
   CONFIG_STDOUT_CONSOLE=n
   CONFIG_PRINTK=n
   CONFIG_EARLY_CONSOLE=n
   
   # Build
   CONFIG_SIZE_OPTIMIZATIONS=y

   
   
   
2. I have added an spm.conf
   
   

   CONFIG_IS_SPM=y
   CONFIG_FW_INFO=y
   CONFIG_GPIO=y
   CONFIG_SERIAL=n

   
   
   and added that to the CMakeLists.txt
   
   

   set(spm_CONF_FILE ${CMAKE_CURRENT_SOURCE_DIR}/spm.conf)

   
   
   
3. I have also configured the hci_rpmsg via the menuconfig to turn off logging
   
   
4. I also tried turning on Power Management via the SPM and HCI_RPMSG's menuconfig's as well but it did not seem to have any effect. 

As for my source code, I have attached it. I simply setup the BLE and handlers and then call:

for (;;) {
    k_cpu_idle();
	}

If we look at the PPK, I see this:

where my baseline current seems to be around 200uA - from what I had read around, I would have expected to be able to get it lower than this, so I imagine I must be configuring something incorrectly. 

If you had any advice, it would be appreciated!

nRF Connect SDK: v1.6.1