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Design >> Analog Design >> Anyone knows how to learn design a programmable res/cap array?
https://designers-guide.org/forum/YaBB.pl?num=1448439604

Message started by Rochester on Nov 25^th, 2015, 12:20am

Title: Anyone knows how to learn design a programmable res/cap array?
Post by Rochester on Nov 25^th, 2015, 12:20am

As I had made a analog filter before and I want to add tunning circuits in it.
I want to use programmable res/cap array to change certain value.
But I hadn't design digital integrated circuits or Mixed signal circuit yet.I searched some digital and analog design books but none of them mentioned it.
Can somebody help me or provide some elaborated books or documents?

Title: Re: Anyone knows how to learn design a programmable res/cap array?
Post by neoflash on Dec 4^th, 2015, 10:58am

Usually you add a switch in series with the R/C will achieve the programming function.

The complexity is:

1. How big the switch it needs to be?

2. Which side should the switch sit?

3. How to deal with the disconnected terminal of R/C? Let it float or bias it somewhere?

These questions are related to detailed specifications of your filter. Those problems are quite fundamental thus not many paper/book will specifically talk deep about it. But they are truly important problem that engineers should not ignore.