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Digital filters in ADC

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What are you trying to filter out? I have an adc on my micro for reading arc voltage from a voltage divider and use a comparator to compare that to a precision pot voltage reference in a high frequency enviroment and dont really have any issues. Maybe you need to recalibrate your adc voltages or rail voltages. Other wise if you have an issue you could build a band pass or high/low pass filter if you can find the freq of the interference. I also use a faraday cage to prevent interference as well as twisted pairs and shielding on the inputs and opto coupling to prevent spikes on the board. There are a ton of solutions available.
Bob
 
Hey Wild, If you jump over to All About Circuits and have a look at volume 2, A/C circuits and read chapter 8 in the Ebook online it will give you how to build exactly what you need. If you already know the freq you wish to attenuate it will give you the circuit and the maths for the exact filter for that frequency. Hope this helps.
Bob
 
Hey Wild, If you jump over to All About Circuits and have a look at volume 2, A/C circuits and read chapter 8 in the Ebook online it will give you how to build exactly what you need.
That article is on analog filters, not digital filters, which the OP wanted.

If you Google "digital filters" you will get many hits. Any digital filter can be used at the digital output of the A/D, there's nothing about the A/D output that requires a special type of digital filter. For lower data rates and simple filters you can do the digital filter in a standard microprocessor. For higher data rates and/or higher order filters, you may need to use a dedicated signal processor chip (DSP).
 
Looks like you're looking for IIR and FIR filters. Good sources of information are Analog Devices, Texas Instruments, and Microchip. They each have tools for calculating responses and how many taps are required (given, type of filter, sampling frequency, input frequency, etc.); although content is usually tailored for their respective DSP devices. Another good source of basic info is **broken link removed**
 
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