Keithley Series 2600 User Manual

A-52
APPENDIX A
Scripts
print(“”)
print(“Vds”, l_vds_bias)
print(“Vgs (V)”,”Id (A)”,”gfs (s)”)
for l_i = 2, l_vgs_steps do
print(l_vgs[l_i],l_id[l_i], l_gfs[l_i])
end --for
end --function Print_Data()
--Transconductance()
Program 11. Threshold
Program 11A. Threshold (Search)
--[[
FET_Thres_Search():
This program performs a binary search on the gate-source voltage (VGS) of an FET at a fixed
drain-source voltage (VDS) and searches for a target drain-source current (ID). If the
specified Id is found within the maximum number of iterations, the threshold voltage (VTH)
and drain-source (ID) currents are measured and printed.
If the maximum number of iterations are reached, the program is aborted.
Required equipment:
(1) Dual-channel Keithley Series 2600 System SourceMeter instrument
(1) SD210 N-Channel FET
Running this script creates functions that can be used to create a threshold search of
FETs. The default values are for an NPN transistor type 2N5089.
The functions created are:
1. FET_Thres_Search(vdssource, lowvgs, highvgs, targetid)
--Default values vdssource = 1V, lowvgs = 0.5, highvgs = 2, targetid =
1e-6A
2. Check_Comp()
See detailed information listed in individual functions.
To run:
1) From Test Script Builder
- Right-click in the program window, select “Run as TSP”
- At the TSP> prompt in the Instrument Control Panel, type FET_Thres_Search()
2) From an external program
- Send the entire program text as a string using standard GPIB Write calls.

Keithley Series 2600 Specifications

General

Brand	Keithley
Model	Series 2600
Category	Measuring Instruments
Language	English