TransistorTester with Curvetracer Upgrade 3
Here I test a depletion-mode Mosfet (BSS129).
It's a little bit strange, if I put the device with
Gate------ TP1
Drain----- TP2
Source-- Tp3
the result is right : 1,2,3 - GDS with Vgs=1.3V
but
if I put it (turned 180°) in the socket,
Gate ------TP3
Drain------TP2
Source---TP1
the result is wrong: 1.2.3 -DGS with Vgs=4.3V
4.3V is near Ubat/Uusb its to high
If I tested it with this pin-assignement, the curves are not from a fet.
Therefore I modified the Transistortester-program for depletion-mode with Vgs greater 4V : I changed the pin-assignment on the interface to the curvetracer:
drain: source ( and source: -drain).
The curves on the Curvetracer looks goot - I think !