Don't find SB-44 on my nRF9160 v0.8.5 dk for current measurment.

[Ubaid]

Hello,

I am trying to configure my nRF9160 v0.8.5 dk for current measurement and found out that SB 44 is missing on my kit. As the user manual suggest that in order to enable P24 for current measurments we have to cut SB44 first. 

Secondly, I am using low end oscilloscope(tektronix TDS 2024C) with minimum resolution of 20mV to measure the small voltage drop(micro volts for micro ampares with 0.5ohm resistance).Do I need some amplifying circuit after P24 to measure with oscilloscope.

Thank you.

Ubaid

[MJD093]

Hi,

Where did you get the requirement for SB 44?

https://infocenter.nordicsemi.com/topic/ug_nrf91_dk/UG/nrf91_DK/prepare_board.html <- this link will take you to the resources on current measurement with the nRF9160 DK. SB43 will disconnect power to the nRF9160 which you can then connect an amp meter to P24 to bridge the power that SB43 would normally supply.

The resource is for the latest version of the DK (v0.9.0) but this is what I had to do for my v0.8.5 DK which still has SB43 cut since I performed measurements several months ago. Simply cut SB43 on your board as v0.8.5 wasn't supplied with a jumper and SB43 is manufactured as closed in v0.8.5.

EDIT:

No idea where Nordic place old DK schematics but here is the section on Preparing the DK in v0.8.5's manual.

[Ubaid]

I was consulting the nRF91 DK user guide v0.7.1. Thank you for correcting me. The second part of question is still unanswered. Can you help me with it?

[MJD093]

Unfortunately no, I wouldn't know how to assist you with that question.

As the question is now marked as solved, I don't think a Nordic engineer will appear here to answer your second question.