Nordic Dongle Power Off mode

[rananna]

I have been struggling to reduce the current on the Nordic Dongle to the  sub 3 uA levels that the specs suggest I should be able to achieve.

I am stuck at achieving a 9-10 uA current in POWER off mode.

Here is an output from the PPK-II in power off mode.

To achieve this I set up 4 GPIO pins to wakeup the nrf52840 from POWER_OFF mode as follows:

// this will enable wakeup from ultra low power mode (any button press)

nrf_gpio_cfg_sense_input(PLUS__PIN, GPIO_PIN_CNF_PULL_Pullup, GPIO_PIN_CNF_SENSE_Low);

nrf_gpio_cfg_sense_input(MINUS__PIN, GPIO_PIN_CNF_PULL_Pullup, GPIO_PIN_CNF_SENSE_Low);

nrf_gpio_cfg_sense_input(ENTER__PIN, GPIO_PIN_CNF_PULL_Pullup, GPIO_PIN_CNF_SENSE_Low);

nrf_gpio_cfg_sense_input(STANDBY__PIN, GPIO_PIN_CNF_PULL_Pullup, GPIO_PIN_CNF_SENSE_Low);

I also disable the button on the board as follows:

nrf_drv_gpiote_in_event_disable(BUTTON_1);

I also turned off the following

1.ram retention

2. logging in sdk_config.sys.

3.NRF_SPI0->ENABLE = 0;

4.NRF_UART0->ENABLE = 0;

I am using the s340 SD in low power mode:

//set up the pwr configuration

sd_power_mode_set(NRF_POWER_MODE_LOWPWR);

power is from a 3v coin battery connected to the VDD pin, not VBUS to avoid the first conversion stage

Does anybody have any ideas on how I can get below 9 uA in POWER_OFF mode?

I am developing for a CR2032 and pwr is everything!

[Stian Røed Hafskjold]

Hi, there are not that many components on the dongle that can leak current really, so I'm not sure. Did you disconnect the debugger when you measure current?

I assume that you unplug the dongle from the USB port when you power it with a coin cell battery, as you cannot use both at the same time.

When you are not using the first regulator stage (high voltage mode) you should connect VDD and VDDH together. You can do this by soldering SB1. You should at the same time open up SB2, because if you connect the dongle into a USB port while SB1 is shorted, the chip will be bricked. So, if you open SB2 the USB power will be disconnected from the dongle, and you're safe.