power profiler kit II wrong voltage and current measurement

RE: power profiler kit II wrong voltage and current measurement

cumhur — Mon, 04 Dec 2023 16:09:07 GMT

i solved the problem. the source of the problem is the power mosfet Q2 (EFC6604R). i replaced it with the same mosfet Q14 since i do not use power input of the device. Anyone who has similar issue can try this. thank you.

RE: power profiler kit II wrong voltage and current measurement

Kenneth — Mon, 27 Nov 2023 19:19:51 GMT

Something seems a bit wrong yes:

TP5 and TP20 are the same. That's good.

TP2 should be the same or 50mV lower than TP5/20, as this is after the sense resistor. However, it's 40-50mV higher, which means there is another source of voltage somewhere that has a higher potential. Short circuit?

TP6 is about 0.6V below TP2, which corresponds to a diode drop. It's questionable whether there has been a short circuit or something there. It could be static electricity or something that has damaged the transistor there.

Kenneth

RE: power profiler kit II wrong voltage and current measurement

cumhur — Thu, 23 Nov 2023 16:51:36 GMT

Thank you for your answer, actually I measured TP6 but I wrote TP7, there was a label confusion. i am using the device in source mode. normally there was a 100-150 nA measured noise while there is no load but it shows exactly 0 uA. When there is a load it also measures it low.

--The OUT_ENABLE signal is active low, so it should be low when active. Since TP2 has the correct voltage, it seems strange that there is an issue.--

VDUT- (tp2) seems correct and it is connected to tp6 with Q2 and Q2 is activated by Q1A which is an N channel mosfet and i think OUT_ENABLE should be active HIGH.

also, below 3V tp2 does not show the correct values, it stucks on 3V. i made some measurements with different voltage values as follows:

3.3v
TP2 3.33
TP5 3.29
TP6 2.74
TP7 0
TP20 3.29

3.6v
TP2 3.62
TP5 3.58
TP6 3.02
TP7 0
TP20 3.58

2.8v
TP2 3.00
TP5 2.96
TP6 2.44
TP7 0
TP20 2.96

1.8v
TP2 3.02
TP5 2.97
TP6 2.46
TP7 0
TP20 2.97

RE: power profiler kit II wrong voltage and current measurement

Kenneth — Tue, 21 Nov 2023 15:58:57 GMT

Hello again!

Here is the feedback from the team.

No, there's no known issue. But based on the information provided, you have probably measured at the wrong test point.

If TP7 is low, you have measured directly at the INPUT pin, and there is no voltage there unless something is connected. You should measure at TP6, which is the OUTPUT, to see if there is any voltage. If TP6 and TP2 are equal, there is no issue with the switch.

The OUT_ENABLE signal is active low, so it should be low when active. Since TP2 has the correct voltage, it seems strange that there is an issue.

Is it in source mode or amp mode? What is the voltage at TP2, TP5, TP6, TP7, and possibly TP20 if it's in source mode?

Kenneth

RE: power profiler kit II wrong voltage and current measurement

Kenneth — Mon, 20 Nov 2023 12:26:08 GMT

Hello,

Let me check with the team that made the PPK II if they have any suggestion.

Kenneth