probe_dc :
A DC analysis probe for measuring DC transfer function.

The probe_dc primitive measures the DC transfer function of a circuit by supplying a DC stimulus (stim) and measuring the circuit’s response (resp). That is, one can measure a DC transfer function by configuring a testbench that feeds the stim output of this primitive to the circuit’s input and connects the circuit’s output to the resp input of this primitive.

The probe_dc primitive produces a DC signal for its stim output, stepping from start to stop at an increment of step. The change in stim can be triggered either internally or externally depending on the value of the parameter period. When period is greater than 0, the change is triggered internally at a period of period after an initial delay of delay. When period is 0, the change is triggered externally whenever the trig input changes to a different value. Before making each change to stim, the probe_dc primitive takes a measurement on the resp input and records the results in a table format to a text file named by the parameter filename. For desired results, the triggering period must be set long enough for the circuit to reach its final DC response. Also, the simulation must be run longer than delay+period*(stop-start+step)/step in order for the primitive to collect the entire transfer function.

Input/Output Terminals

Name	I/O	Type	Description
stim	output	xreal	stimulus (to circuit)
resp	input	xreal	response (from circuit)
trig	input	xbit	trigger input

Parameters

Name	Type	Default	Unit	Description
filename	string	“probe_dc.dat”	None	output filename
start	real	0.0	None	start value
stop	real	1.0	None	stop value
step	real	0.1	None	step value
period	real	0.0	seconds	trigger period
delay	real	0.0	seconds	initial delay