Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
18 years ago

Low Pass IIR filter using cyclone II FPGA

Hi everyone, I hava a task to implement low pass iir filter on cyclone II FPGA. The parameters of filter are the following: fp=5kHz; pass band frequency fs=8kHz; stop band frequency Fs=44k...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
18 years ago

Hi Koce,

this will depend also on the type of DAC that you are using.

If you take care that your digital filter has a unity gain the digital output of the filter will have the same dynamic range of the filter input, which is the ADC output.

So if you have a DAC that is capable of generating a [-5V,+5V] output you will be able to generate an analogue signal with the same voltage range, if you need it.

Take care that most of the DACs are with current output and the output voltage range is determined by resistors tied to ground at the DAC output so you can choose your output swing with some freedom.