Section 3: Test subroutine library reference
S530 Parametric Test System Test Subroutine Library User's Manual
3-6
S530-907-01 Rev. A / September 2015
beta3a
This subroutine calculates beta (
) at collector-emitter voltage (V
CE
) and collector-emitter current (I
CE
) using the
searchi
and
trig
LPTLib functions to search base-emitter current (I
BE
) until the target I
CE
is reached. The
device is in the common-emitter configuration.
Usage
double beta3a(int
e
, int
b
, int
c
, int
sub
, double
ice
, double
vce
, double
ibe1
,
double
ibe2
, double
vsub
, double
*ibe
, double
*cmeas
, double
*error
);
e
Input
The emitter pin of the device
b
Input
The base pin of the device
c
Input
The collector pin of the device
sub
Input
The substrate pin of the device
ice
Input
The targeted collector current, in amperes
vce
Input
The forced collector-emitter voltage, in volts
ibe1
Input
The start of the base-emitter current (I
BE
) search, in amperes
ibe2
Input
The end of the base-emitter current (I
BE
) search, in amperes
vsub
Input
The forced substrate bias, in volts
ibe
Output
The final measured emitter-base current
icmeas
Output
The final measured collector-emitter current
error
Output
The percent error between the target collector current (I
CE
) and the final
measured collector current (I
CMEAS
)
Returns
Output
The calculated beta:
-1.0
= Target I
CE
= 0.0
-2.0
= Base voltage limit reached
Details
This subroutine sets the current trigger on SMU1 at the specified I
CE
. The base current is searched
until the trigger is set. The base current is then forced, the collector current measured, and
is
calculated.
The percent error (
error
) is calculated between the target I
CE
and the final measured I
CE
and
returned.
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 +I
CE
, +V
CE
, +I
BE,
-V
SUB
PNP -I
CE
, -V
CE
, -I
BE
, -V
SUB
