Build my own Chipwhisperer (Question 2)


I’m testing the power supply on my chipwhisperer. Now I found out, that the differential output is labeled with 9v, but there are 7,5v. When I look on the resistors on the LM337, LM317, they say too 7,5v.
Which is the right voltage ? What is the voltage on they produced by you ?


Ah - yes it actually works out to 7.5V, IIRC the DC-DC converter is generating +/-9V (poorly regulated), which then passes through the LM337/317 to give you around +/-7.5V. Later versions of the PSU go to about +/-7.8V. The actual voltage isn’t too critical as long as it’s (a) above about 7V and (b) stable. This lets you use the diff-probe on 5V systems and ground shunts. So long as the voltage is fairly stable you won’t have drift issues (drift isn’t a huge deal with the ChipWhisperer input either as it’s AC-coupled).



Thank you, my hardware is now working correct :slight_smile:
Now I try to understand the software.