Section 3: Test subroutine library reference
S530 Parametric Test System Test Subroutine Library User's Manual
3-26
S530-907-01 Rev. A / September 2015
Details
This subroutine estimates the forward early voltage of a bipolar device at constant IBE. The device is
connected in the common-emitter configuration, and a collector-emitter voltage (VCE) and collector-
emitter current (ICE) data set is generated. A linear least squares (LLSQ) line is fit to the data, and
the X-intercept is returned as the forward early voltage. The correlation coefficient is returned as an
estimate of the fit.
When calling this routine, make sure the VCE start and stop values have the device well into
saturation.
If a zero or negative substrate pin is specified, the substrate is left floating. If the pin number is
greater than 0 and V
SUB
is less than 0.9 mV, the substrate is grounded. In all other cases, it is
connected and forced.
V/I polarities
NPN +VCE, +IBE and -VSUB
PNP -VCE, -IBE and -VSUB
Source-measure units (SMUs)
SMU1: Sweeps VCE, default current limit, measures ICE
SMU2: Forces ibe, 3 V voltage limit
SMU3: Forces vsub, default current limit
Example
ev(e, b, c, sub, ibe, vstart, vstop, npts, vsub, &slope, &iflag, &r, &early);
Schematic