> Don't worry, it isn't another part. It's a combination of parts, or rather > an adjective describing a noun. For example, each input of a 110 ring mod > has a switched cap. In the case of limiters using switched caps for time > settings, it's a rotary selector switch with a different capacitor for each > setting -- regular, BBQ, or extra-crispy :) Bzzzzzzzzzzzzzzzzzzzzzz! -10 points. A 'switched cap' is a semiconductor structure that implements a variable capacitance by modulating an analog switch at high frequencies. National, Linear Tech, and Maxim all make various filter ICs that you feed in a digital clock that is usually 100X or 50X the cutoff frequency. They do not have resonance. Other similar structures are 'flying capacitors', which are used in some analog-to-digital converters. Entire books and 1000s of papers have been written on these structures. They are not in widespread use, because of cost (not all that cheap) and they tend to be noisy. Paul S.
Message
Re: [motm] variable capacitors (was: Schematic Icon Reference)
2001-06-20 by Paul Schreiber
Attachments
- No local attachments were found for this message.