Keithley S530

S530 Parametric Test System Test Subroutine Library User's Manual Section 3: Test subroutine library reference
S530-907-01 Rev. A / September 2015 3-21
Source-measure units (SMUs)
 SMU1: Forces I
EBO
, programmed voltage limit, measures bvebo
Example
result = bvebo(e, b, c, sub, ipgm, vlim, type);
Schematic
cap
This subroutine measures the capacitance of a two-terminal device.
Usage
double cap(int hi, int lo, int sub, double vbias);
hi
Input
The HI pin of the device
lo
Input
The LO pin of the device
sub
Input
The substrate pin of the device
vbias
Input
The voltage bias on the device, in volts
Returns
Output
Measured capacitance
Details
This subroutine measures the capacitance of a two-terminal capacitor at a specified voltage. The
voltage is provided by the internal capacitance meter bias supply. The result is returned in farads.
If a positive substrate pin is specified, the substrate is grounded. If a positive substrate pin is not
specified, the substrate is left floating.
When using this routine for junction capacitance measurements, make sure the junction never
becomes forward biased. To prevent this, make sure the forward voltage is less than one-half the
barrier potential (for silicon, this means that the forward voltage (V
F
) should not exceed 300 mV to
350 mV).
At the onset of conduction in a forward-biased diode (V > 300 mV), the current flow causes
unpredictable readings in the capacitance meter (usually overrange, 10
22
).