Measuring the linearity of a switch

[christianlillebrekke]

Hi,

Has anyone got any tips on how to measure the linearity of a switch, without using a complete switchcap circuit.

I need to compare the linearity of two bootstrapped switches.

Christian

 

[mr_chip]

You can simply simulate the on-resistance of the switches as a function of the input voltage. Apply a small fixed Vds (e.g. 100 mV) over the switch and get its ratio to the switch current. You will see then the variation of R which causes non-linearity

 

[christianlillebrekke]

I have simulated the on-resistance, but isn`t non-linearity caused by both on-resistance and junction capacitances? The dominating of them is determined by the output impedance of the source. I would like to get a plot of the harmonic distortion (2nd and 3rd harmonic) versus the output impedance of the source.
How can I do this in ELDO?