PPK2 Digital Port voltage for High and Low Level

[Max01]

Hello,

I'm working with Power Profiler Kit II and i see that we can use a digital port.
I would like to know what the electrical levels for a valid High and Low.
I can't find any informations in the documentation.

Best regards,

[Simon D-M]

Hi Maxime,

The high and low voltage depend on the voltage you put on the VCC pin from the Logic port.

• A digital 1 starts at 0.65 x VCC
• A digital 0 is until 0.35 x VCC

So if the VCC is at 3.3V it means that a 1 is >2.145 and a 0 means <1.155V

The VCC pin must be between 1.6V and 5.5V. If you are under, the digital input might not work. And if you are over, you might break the device. 

I also want to make you aware that the logic ports on the PPK2 are sampled with a 100kHz frequency with a typical bandwidth of 50kHz.

Best regards,

Simon D-M

[Max01]

Hi Simon D-M,

Thanks for your answer,

I have another question about sample rate.
I see in the documentation that the PPK2 samples at 100K samples/s.
But if i understand corectly this is the window that only keeps a lower amount of samples.

My question is : if i use Power Profiler software with 100K samples and i want to monitor 500 days of sample and if i have an enough hard drive.
Can i save 500 days of samples with 100K sample resolution ?

Best regards,

[Max01]

Hi Simon,

Thank you for clarifying the situation.

That's very intresting if the only limitation now is drive space.
I'm thinking to use it to make a benchtest to monitor consumption or my device for a long time.
Could you tell me if it's possible to get data from a script ?

Best regards,

[Simon D-M]

Hi,

Theoretically it is possible to talk to the PPK2 directly, but I would strongly recommend using the nRF Connect application "Power Profiler". It can export the measurement in CSV after the measurement. And then you can have a script that analyze your data.

Best regards,

Simon D-M

[hmolesworth]

I disagree slightly with the quoted electrical High and Low digital voltage inputs, if I may. The digital inputs are buffered via a Digital io port input buffer/level shifter FXMA108 on 3V3 (3.3Volts).

"The FXMA108 is a configurable dual-voltage supply translator designed for both uni-directional and bidirectional voltage translation between two logic levels. The device allows translation between voltages as high as 5.5V to as low as 1.65V. The A port tracks the VCCA level and the B port tracks the VCCB level."

• VinL = 0.35 * 3.3 = 1.155V
• VinH = 0.65 * 3.3 = 2.145V (not the quoted 2.9V)

data-sheet/pdf/fxma108-d.pdf

[Max01]

Hi,

Thanks for this informations,
I don't have any more questions now.
Thanks for your helps,
Best regards,

[Simon D-M]

Hi,

Correct! I'm sorry I misread the datasheet. The logic '1' is indeed 0.65 x Vccx.

Best regards,

Simon D-M