SQRTI - Square Root of Current

Old Content - visit altium.com/documentation

Modified by Phil Loughhead on Mar 4, 2014

Model Kind

General

Model Sub-Kind

Spice Subcircuit

SPICE Prefix

Model Name

SQRTI

SPICE Netlist Template Format

@DESIGNATOR %1 %2 %3 %4 @MODEL

Parameters (definable at component level)

None

Notes

The content of the sub-circuit file (SQRTI.ckt) associated with this model is shown below. The formula/equation used to provide this function is declared as part of the netlist-specific entry, under the .SUBCKT line of the file.

*Square root of Current .SUBCKT SQRTI 1 2 3 4 VX 1 2 0 BX 4 3 I=SQRT(I(VX)) .ENDS SQRTI

Examples

Consider the circuit in the image above. With respect to the SQRTI component, the entries in the SPICE netlist will be:

*Schematic Netlist: XM1 IN 0 OUT 0 SQRTI . . *Models and Subcircuit: .SUBCKT SQRTI 1 2 3 4 VX 1 2 0 BX 4 3 I=SQRT(I(VX)) .ENDS SQRTI

The effect of the function can be seen in the resultant waveforms obtained by running a transient analysis of the circuit.

In this example, the following analysis parameters on the Transient/Fourier Analysis page of the Analyses Setup dialog have been used:

Transient Start Time - set to 0.000
Transient Stop Time - set to 50.00m
Transient Step Time - set to 200.0u
Transient Max Step Time - set to 200.0u