Keithley 2651A Reference Manual page 176

Model 2651A High Power System SourceMeter® Instrument Reference Manual
Measuring current
The following inputs are required to test leakage using the factory leakage script, as shown in the
script example below.
•
SMU: Sets the Model 2651A source-measure unit to use
•
levelv: Setting the voltage level to source
• limiti: Sets the current limit for discharging or charging the capacitor
•
Sourcedelay: Solve the following equation to determine the amount of time before taking a current
reading:
i =
Where: i is the limiti setting and current limit
•
measurei: Sets the current measure range
•
measuredelay: Defines the delay after the limit is lowered to measure before the measurement is taken
Script example
Use the smua.source.highc attribute to set and control the options for high capacitance mode.
The programming examples (and figure) below illustrate how to enable high-capacitance mode on
SMU A.
1. To enable high-capacitance mode, send:
-- Enables high-capacitance mode.
smua.source.highc = smua.ENABLE
2. To run the i_leakage_measure() function in the KIHighC factory script, send:
-- Charges the capacitor.
smua.source.levelv = 5
smua.source.output = smua.OUTPUT_ON
delay(1)
imeas = i_leakage_measure(smua, 0, 1, 300e-3, 10e-6, 100e-3)
-- The parameters in the i_leakage_measure() function represent
-- the following:
-- smu = smua
-- levelv = 0 V
-- limiti = 1 A
-- sourcedelay = 300 ms
-- measurei = 10 uA range
-- measuredelay = 100 ms
Adjust the voltage level and source delays based on the value and type of capacitor along with the
magnitude of the voltage step and the current measure range.
2651A-901-01 Rev. A / March 2011
Δv
C ----- -
Δt
NOTE
Section 3: Functions and features
3-69