Power Profile Kit PPK2 current not correct.

[WFKwok]

Hello,

i have one PPK2. Recently i find the current reading from PPK2 is relatively large compared with actual current value.

For example, actual current value vs PPK2 value:
4uA vs 35uA
3mA vs 6mA
300mA vs 500uA

So is the PPK already broken or defective?s

Is there any way i can work around like PPK2 calibration to fix the PPK2?

Or something like the current sensing resistors are broken and i can check and replace to get a good PPK2 back?

Thanks

[Edvin]

Hello,

What do you base your "actual current values" on? And which ones are the lower of the numbers that you present? The PPK or the "actual current value"?

Please note that we will be out on public holiday in Norway from Thursday this week until Tuesday next week. Please expect some delay in our replies. I am sorry for the inconvenience.

Best regards,

Edvin

[WFKwok]

Hi Edvin, 

i compared the current values with a digital multimeter, that is verified the reading is accurate.

The values at the left hand side are from multimeter.

The values at the right hand side are from PPK2.

4uA vs 35uA

3mA vs 6mA

300mA vs 500uA

The current values measured by PPK2 are relatively higher than the actual values.

I suspect something like the current sensing resistors are broken on PPK2, possible? And any way i can check and replace to get a good PPK2 back?

[Edvin]

Hello,

Although a multimeter may be accurate, it may be that it is not that good at measuring continuously changing signals. You can see from the PPK2 measurements that you probably have a lot of very thin and high peaks (coming from when the radio is being used). I suspect that the multimeter is not capable of capturing the height and length of these (or capture them at all). I would say that your best readings are probably the PPK2. If you want to ensure, you could compare it to reading using an oscilloscope, and comparing the results to that one. 

What HW are you measuring on? Is it a DK of some sort? Perhaps you can send me the application, and I can verify by measuring using my PPK here in the office?

Also, you can compare the measurements with what you can expect from the application using the online power profiler. Note that this is the expected current consumption only for the clocks and radio, so if you for example have UART logging, some external sensor or something else running, that may increase the actual current consumption.

Best regards,

Edvin

[WFKwok]

I have verified the current with another set of PPK2 (let say this as good PPPK2).
This good PPK2 can get the same results as multimeter. (for example 3mA) 
However the bad PPK2 get the current is around 6mA with the same device under test.

We purchased it from digikey/mouser few year ago, I forgot...need to check.
So is there any way I can send back to Nordic for repair or other channel for RMA?

Please kindly advise. Thanks!!

[Edvin]

Are there any differences between the two? Are there any revision differences between them?

Best regards,

Edvin