Current consumption of PMOD Board

[rajat_amd]

Hi Team,

What is the current consumption for below PMOD Boards?

 

We are designing host board so want to make sure how much current will take below board on 3.3V

 

Pmod USBUART

Pmod ACL

https://digilent.com/reference/pmod/pmodacl/start

https://digilent.com/reference/pmod/pmodusbuart/start

 

[JColvin]

Hi @rajat_amd,

I do not have typical current values for the two Pmods specifically, but this is what I found when looking at their datasheets:

Pmod ACL, based on the Figures 32 and 33 within the ADXL345 datasheet, https://www.analog.com/media/en/technical-documentation/data-sheets/ADXL345.pdf, appears it will have an upper current consumption around 175 uA when operating at 25 °C at most data rates. The dual inverting buffer, https://www.onsemi.com/pdf/datasheet/nc7wz16-d.pdf, looks to have a maximum quiescent current of 10 uA.

For the Pmod USBUART, I am presuming that you powering both the module and the system board that it is attached to from the same power source (as there is an on-board jumper option to power the system board from the Pmod USBUART itself, but I highly doubt your system board only needs 50 mA). Its datasheet, https://ftdichip.com/wp-content/uploads/2020/08/DS_FT232R.pdf, indicates a normal operating supply current of 15 mA (USB suspend current of up to 100 uA).
The 2 LEDs used to indicate USB activity are more tricky to get a good value for as they won't be constantly lit up. So making up a value of 50% duty cycle, and using the 2 V forward voltage with the 470 ohm resistors, the pair of LEDs will be taking around 3 mA total.

I would guess then that this puts the Pmod ACL at around ~185 uA and the Pmod USBUART at ~18 mA when operating at 3.3 V. I'll leave it to your design team if they want to budget some extra padding onto those values for any unexpected spikes in start-up or something like that.

Let me know if you have any questions.

Thanks,
JColvin