DC Sensitivity

This is a stand-alone analysis mode and should not be confused with the sensitivity/worst-case sweep mode and multi-step mode.

This control instructs the simulator to perform a DC sensitivity analysis. In this analysis mode, a DC operating point is first calculated then the linearised sensitivity of the specified circuit voltage or current to every model and device parameter is evaluated. The results are written to the list file and they are also placed in a new data group. The latter allows the data to be viewed in the message window (type Display) at the command line and can also be accessed from scripts for further analysis.

This analysis mode performs a similar analysis to a sensitivity sweep applied to a DC analysis. However it differs in that it calculates the sensitivity of every parameter in the circuit, not just those with a distribution function applied. Also the way the analysis is performed is different. The sensitivity sweep perturbs each parameter and performs a full non-linear DC analysis for each case. This analysis mode uses some matrix arithmetic to calculate an approximation to the true sensitivity.

Setting up a DC Sensitivity Analysis

Place a control of the following form in the F11 window:
.SENS V(nodename [,refnodename])| I(sourcename)

Output node to which sensitivities are calculated
refnodename Reference node. Ground if omitted
sourcename Voltage source to measure output current to which sensitivities are calculated.