Created by Created May 10, 2012 Last modified May 10, 2012 Tags

### Summary

A behavioural capacitor where the capacitance is programmable by the voltage on the 'capacitance' net.

However, simulation fails with:
Solve Aborted - Error in Transient Solver invalid col index

### Description

A behavioural capacitor where the capacitance is programmable by the voltage on the 'capacitance' net. A 1uF capacitor is shown for reference.

Changing the expression to I(Vint1.nA)*(I(R2.nA) would allow the capacitance to be programmed by the current in R2.

The expression can be scaled. For example:

I(Vint1.nA)*1u*V(capacitance)


would produce a 1uF capacitor resistor with a V(capacitance) of 1V rather than 1uV.

BEWARE! A negative value of control parameter will produce a negative capacitance. Adding an ABS() function will prevent this:

I(Vint1.nA)*ABS(V(capacitance))

However, simulation fails with:

Solve Aborted - Error in Transient Solver invalid col index