SV: Re: [sdiy] Nonlinearities in IR3109 filters

[Antti Huovilainen]

On Thu, 3 Aug 2006, karl dalen wrote:

> Hmm, what is this smal signal range we are talking about?
> 20-40mV trough the ladder?

For transistor ladder the level is < 10mV for 1% nonlinearity (of course 
this is affected by feedback so the actual nonlinearity depends heavily on 
cutoff and signal freq content).

> So what hapends above these levels?

All linear methods break down. This includes pole-zero analysis.

I've only looked at modelling diode ladder filter nonlinearities enough to 
say that it'd probably result in a few dozen papers filled with very 
unpleasant equations. Plus I hate the 303 :)

Antti

"No boom today. Boom tomorrow. There's always a boom tomorrow"
   -- Lt. Cmdr. Ivanova