nrf5340 sleep currrent consumption

[Lavanya_Manohar]

In our custom board nrf5340-nrf7002, tried system_off(C:\ncs\v2.6.1\zephyr\samples\board\nrf )sample to check power consumption. 

But it measures 0.60mA

Is there any config need to address? please provide debug steps

[Priyanka]

Hi Lavanya,

Do you have any peripherals connect to the 5340? Have you made any hardware changes?

Regards,

Priyanka

[Lavanya_Manohar]

Hi priyanka,

Priyanka said:

Do you have any peripherals connect to the 5340?

In our custom board, nrf7002 is connected to 5340 but we keep it OFF by hardware control.
Then we have one capacitve interrrupt connected to 5340, we have isolate the interrupt and then measures reduced to 0.46mA. 

[Priyanka]

Hi Lavanya,

Here are a few of my suggestions:
PLease check that all the unused GPIOs are properly configured. And also ensure that all peripherals that are not used are disabled. Is your firmware configured to low power modes? When the nRF7002 is connected to the nRF5340, even if it's OFF, this can still affect the power consumption. 

Regards,

Priyanka

[Lavanya_Manohar]

Hi Priyanka,
Thank you for your support.

Somehow we manage and reduced the current measurement in our board. Below are the current consumption measurements and challenges we are facing:

• Current Consumption:

  • nRF5340: ~30 µA in sleep mode.
  • nRF7002: ~2 µA in idle mode (shut down during sleep).
  • We are working on further reducing the nRF5340's current consumption.

• Application Details:

  1. Wi-Fi module is set to idle and shut down during sleep.
  2. Console/UART is suspended before entering idle mode.
  3. SPI/external flash is suspended before entering idle mode.
  4. I2C is suspended before entering idle mode.
  5. A Counter Timer is used for periodic wakeups.

• Issue:
  The nRF5340 sleep current documentation indicates consumption as low as ~5 µA in many scenarios. However, we are seeing 30 µA, which seems higher than expected.
  Could you please clarify this?

• Debugging Observations:
  We measured voltage on various pins during sleep and observed:

  • COEX-related pins, IOVDD, HOST IRQ, and QSPI pins show voltages ranging from 1V to 3.3V.

Could this be causing the higher current consumption? If so, what steps can we take to mitigate this?

• Request for Suggestions:
  We would need your guidance on:
  1. Understanding the expected sleep current for nRF5340 in this scenario.
  2. Eliminating potential issues related to COEX and other pin voltages.
  3. Any additional steps to optimize current consumption further.

[Priyanka]

Hi,

Are you using the COEX related pins? If you are not using them, then it's better to configure them as disconnected inputs in the dts or explicitly set as inputs with no pull resistors in your application.

Make sure there are no floating pins. Also make sure that the external flash is in a deep sleep mode. Also make sure that the IOVDD is not connected to any unused GPIO pins. Try to set all unused GPIO pins to disabled and try not to leave them floating. 

If you still have current issues, maybe you could try to isolate the current readings on 5340 and 7002 to see which causes the extra leakage. You can also to check the current measurements on each CO-EX related pins to see which has a spike.

-Priyanka