Digital Filter Design in Cadence

[analogonics]

I am new to digital filters. I want to design a digital filter that takes the output of an 8-bit ADC, low-pass filter the codes and give an output digital *filtered) 8-bit code.

I can make a VerilogA code, but it is more analog. I want something which takes in 8-bit code, filters and then gives an 8-bit code.

Does anyone have any leads, ideas, anything would be helpful.

 

[KlausST]

Hi,

at first you should define your filter characteristics.

also: FIR or IIR how many taps .. or any information we can work with.

****
The simplest is something like this:

OUT = (IN - OUT) * x + OUT
Where 0 < x >= 1

I recommend to do the math (multiplying and adding) with more than 8 bits resolution.

It works like an RC in analog world.


Klaus

 

[FvM]

Suggested filter is 1st order IR.
x = 1 - exp(-Ts/T1) ; Ts sampling time, T1 low pass time constant = 1/omega,g, approximate x = Ts/T1
suggested extra bits for accumulator -log2(1/x), e.g. 3 extra bits for x = 1/8

 

[analogonics]

could you please suggest any implementation examples in cadence from scratch for any filter type.

 

[KlausST]

I´m sure if I do an internet search I´ll find many, many.

Thus I suggest you to do the same first. Read thorugh them and then give use the informations what is good or not good on them. By giving links to the occording documents.


Currently it´s like: Please suggest me just any type of shoe.
After that I can tell you my size and what a need them for, and my preferred color and my preferred material and and and.

Klaus