Differential Conductance Process - Keithley 2182 User Manual

I-14 Delta, Pulse Delta, and Differential Conductance

Differential Conductance process

Differential measurements can be used to study the individual slopes of an I-V (or V-I)
curve. By applying a known differential current (dI) to a device, differential voltage (dV)
measurements can be performed. With dI and dV known, differential conductance (dG)
(and differential resistance dR) can be calculated.
This differential measurement process is shown in
ured to output a stepped sweep with a specified Delta, which is the differential current
(dI). As shown in the illustration, Delta is added to and subtracted from each subsequent
step in the sweep. The solid line in
As shown, each differential voltage calculation (dV Calc) uses the three previous
Model 2182/2182A A/D measurement conversions. Keep in mind that dI (Delta) is the
same for all calculated points. With dI known and dV calculated, the Model 622x can also
calculate, display, and store the differential conductance (dG) or differential
resistance (dR) for each calculated point.
Figure I-7
Figure I-7 is the actual output of the Model 622x.
. The Model 622x is config-