9160 external crystal oscillator power consumption issue

[tinyk.hu]

hi 

   After switching the 9160 crystal oscillator to an external crystal oscillator, we found that the power consumption of the MCU increased by approximately 1.2 mA constantly, regardless of whether it was in sleep mode or active mode. The switching function we used for testing is shown below.

Is the power consumption increase of 1.2 mA after switching to an external crystal oscillator in line with the actual design parameters of the nRF9160?

[Kazi Afroza Sultana]

Hello,

'' After switching the 9160-crystal oscillator to an external crystal oscillator, we found that the power consumption of the MCU increased by approximately 1.2 mA constantly''

Are you sure that you have no other unused peripheral is not in the application?

You can try to run a minimal sample (following this blog (8) Getting started with current measurements on the nRF9160 - nRF9x - Hardware design, test and measuring - Nordic DevZone) on the nRF9160 without external crystal and measure the current. If you get uA level current then you know your board is ok.

Then on the same application, enable only external crystal only configuration without other application logic and compare the two current measurement value. You can see how much extra current is caused by the external crystal / HF clock configuration alone, without other variables changing.

[tinyk.hu]

hi

Yes, this is exactly how we conducted the comparative test.

When the external crystal oscillator is not enabled, the current after the MCU enters sleep mode is approximately 9 μA.

After the external crystal oscillator is enabled, the current after the MCU enters sleep mode is approximately 1.2 mA.

[Kazi Afroza Sultana]

Hello,

This shows also increased current aprrox 0.96 uA when HFXO is used

PDM