Keithley S530 User Manual

Section 3: Test subroutine library reference S530 Parametric Test System Test Subroutine Library User's Manual
3-68 S530-907-01 Rev. A / September 2015
Details
This subroutine estimates the "pinch-off" voltage for a MESFET at a specified drain voltage and
fraction of I
DSS
. First, it measures I
DSS
, and then searches for a gate voltage that achieves a targeted
"pinch-off current" (ip). The ip output parameter is normally described as a fraction of I
DSS
(usually
0.02 of I
DSS
). The trigger and search routines are used to find the V
GS
that forces the targeted
drain-source current (I
DS
) value (ip).
If a positive substrate pin is specified, the substrate is grounded. If a positive substrate pin is not
specified, the substrate is left floating.
The factor for I
DSS
is normally 0.02.
This subroutine does not call the idss subroutine.
Source-measure units (SMUs)
 SMU1: Forces V
DS
, programmable current limit, sets trigger on I
P
(I
P
= I
DSS
* factor)
 SMU2: Searches V
GS
, default current limit
Example
result = vp(d, g, s, sub, vdss, idlim, factor, v1, v2, &idss, &ip, &iflag)
Schematic

Keithley S530 Specifications

General

Brand	Keithley
Model	S530
Category	Test Equipment
Language	English