Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [iir]

IIR filters can be implemented with both analog and digital components. DSPs often has instructions that are optimizes for creating filters, FIR included.

See also

28 questions
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Good filter design software for Mac OS X/Unix?

I need to implement a simple lowpass filter for a data acquisition circuit (using stretch conductive fabric as a resistive sensor). Various sources have recommended that the best way to go about this is to use filter design software. I haven't found…
terrace
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Code example for FIR/IIR filters in VHDL?

I'm trying to get started with DSP in my Spartan-3 board. I made a AC97 board with a chip from an old motherboard, and so far I got it to do ADC, multiply the samples for a number <1 (decrease volume) and then DAC. Now I'd like to do some basic DSP…
hjf
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IIR filters what does infinite mean?

I am having difficulty understanding what "infinite" in IIR means in practice..In theory the impulse response is used for feedback..If this feedback never ends how output is generated?
GorillaApe
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Is it possible to create an IIR filter in an FPGA that's clocked at the sample frequency?

This question is about implementing a IIR filter in a FPGA with DSP slices, with very specific criteria. Lets say you're making a filter with no forward taps and only 1 reverse tap, with this equation: $$y[n] = y[n-1] \cdot b1 + x[n]$$ (see…
Marcus10110
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Does somebody know about a tool to design filters for DSPIC?

I have to make a filter with DSPIC33 and I want a program that design the filter (there are a lot), yet export code to DSPIC (in c, any compiler or assembly).
Tomas
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IIR filter on a 16bit MCU (PIC24F)

Im trying to implement a simple first order IIR filter on a MCU (PIC24FJ32GA002), without success until now. The filter is a DC tracking filter (low pass filter) whose purpose is to track DC component of a 1.5Hz signal. The difference equation was…
rasgo
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Is my IIR implementation (in C) correct for this difference equation?

I recently started developing a digital regulator for a DCM boost (Digital regulator for DCM Boost - How does it relate to duty cycle?) And I've implemented the difference the following controller in C: $$ G_{Z} = \frac{1.39 z^{-1} - 1.332z^{-2} }{2…
JustAnEngineer
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Conditions for realizing a filter

I was reading a chapter in a textbook on Infinite Impulse Response filters. The author in the beginning of the chapter states that" impulse response h(n) for a realizable filter is " h(n)=0 for n<=0 Can anyone please tell me why? If the answer to…
Infusion of Wormwood n Asfodel
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low pass filter design for accelerometer

I find the following code for a simple implementation of a low pass filter. #define alpha 0.1 accelX = (acceleration.x * alpha) + (accelX * (1.0 - alpha)); I have been experimenting with the value for alpha. But I want to know how exactly we can…
user2155669
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Relationship between order of filter and impulse response?

I see that the slope of the frequency response of a filter (such as the Elliptic, Butterworth...) becomes steeper as its order increases; for instance, a low pass Elliptic filter with an order of N=3 has a much slower rate of change in the frequency…
aralar
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Is a IIR digital filter with a0=1 effectively a FIR digital filter?

I have been experimenting with several digital filters for my thesis recently, and while learning about the FIR and IIR kind, they seem to have similar output expressions. While using a Java class I found online to design a Butterworth IIR Filter's…
ravemir
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Is it possible to compute delay with an IIR filter between peaks?

I am developing a project which receives accelerometer signals as input, which must then be analysed via peak-detection algorithms (among other techniques). In order to do so more effectively, I first filter the signal with a low-pass Butterworth…
ravemir
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How can I prevent my IR sensor from sensing the sunlight?

I want to use an IR sensor for object detection. An LED will be turned on if an object is detected. But because of sunlight, it's malfunctioning (i.e. always getting logic 1). So, how do I omit the interference due to sunlight?
glibin dsilva
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Find filter's frequency characteristics from its impulse response

Impulse response is defined as . Its plot looks like this: Now I am basically supposed to say what does filter do with incomming signals based on this formula or plot. How can I approach this problem?
John Smith
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problem with fixed point butterworth implementation

I have designed a 2nd order Butterworth filter with MATLAB fdatool for VHDL implementation. the cuttoff frequency is less than Fs/10, which should be okay since fdatool uses prewarping. Indeed, the floating point implementation works fine. However,…
Mordechai Salomon
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