A filter modifies signals based on their frequency.

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Transfer function and its magnitude

Can anyone make the transfer function and magnitude of the transfer function more intuitive for me? I understand using them but I feel like there is still a gap in my understanding. I would like to ...
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1answer
25 views

Implementing High Pass Filter in Simulink

I am trying to implement the following block diagram using Simulink in Matlab. I am having trouble getting the high pass filters to work properly. To do the filtering, I am using the First and ...
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1answer
28 views

Is it possible to design cascaded LC filters with inductors sharing the same core?

I want to design an higher order LC filter for filtering out a power signal. In the theoretical design, the inductors are supposed to be on separate cores. But in practice, it will be very costly and ...
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1answer
46 views

Lowpass filter design with transimpedance and difference amplifiers

I have a DDS chip with complementary current outputs that I need to filter. I'm using a design like this: I need a different cutoff frequency, however - 2MHz instead of 50KHz. Note that I'm not ...
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3answers
51 views

Physical significance of group delay

What is the physical significance of the group delay of a system/filter?. Why is the slope of the phase response critical in a communication system.
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2answers
68 views

Are those two filters equal?

Are those two filters equal to each other in their functionality? Of not, what is the difference between them mathematically speaking (zeros, poles, etc)? Also, what is the difference in their ...
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1answer
39 views

Band pass filter [duplicate]

What is this bandpass filter transfer function derivation? http://imageshack.com/a/img674/9016/mKXqCQ.jpg
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30 views

Derivation of the transfer function of band reject filter

What is the derivation of the transfer function of this band reject filter?
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0answers
43 views

Noise on audio circuit when powered by USB

I built a simple microphone boost circuit which works well with a 3V coin cell however when I switch to USB to power it (battery removed, of course), there's a bit of noise in the 200Hz to 10KHz ...
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1answer
29 views

Size of passives for active filter

I am working with the CS42436 codec, and in their datasheet, they have recommended values for components to be used in an active filter that takes the differential outputs from the DACs and converts ...
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1answer
65 views

Can I replace capacitor with multiple lower value capacitors in filter?

Can I replace higher capacitance value MLC capacitor in Sallen-Key topology filter with 2-3 lower value capacitors in parallel (with total capacitance equal to replaced cap)? I tried it in TINA-TI and ...
2
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1answer
66 views

A-D conversion: effect of adding more bits

Say you have a digitizer that's converting an analog signal and feeding it to a microprocessor for whatever you'd like to do to it. How would increasing the number of bits of the digitizer affect the ...
2
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2answers
57 views

A simple RL circuit, getting transfer function, matching with results

I'm doing little lab exercise with an RL circuit. I need to check if I did this analysis right, because the numbers I got and the numbers that should theoretically be there are so far off, I figured ...
7
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1answer
119 views

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 ...
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2answers
108 views

Why does my bandpass filter act as highpass?

I have designed a bandpass filter. Here is the circuit and spectral characteristic: As you can see from the response curve, it has cutoff with the peak ranging from 260 kHz to 290 kHz. Here is ...
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0answers
48 views

A band pass filter simulation in PSpice

I designed a Constant K (I don't remember the constant K) LC band Pass filter with lower cut off frequency 1 KHz and upper 5 KHz. Using the value of K, I deduced the values of L and C and made the ...
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2answers
198 views

Understanding cause of arcing in AC filter circuit

I have an induction hot-plate that one day blew a fuse in my distribution panel when plugging it in. (With the obligatory smoke from the device of course...) On visual inspection, only the AC filter ...
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2answers
40 views

Passive Filter Negative Insertion Loss

Can someone please explain to me how a passive filter could possibly have a negative insertion loss? In the attached picture, this can be seen in the C or D curves where the insertion loss dips below ...
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1answer
48 views

Is it possible to calculate the load resistance in a full bridge rectifier when given only power, inductance, and input voltage?

I'm given a full bridge rectifier circuit with values for power, industance, and RMS input voltage: [P = 380 W, L = 85 uH, Vs = 115 V]. The question states to 'select' output resistance for a ...
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3answers
104 views

RC bandpass filter, what's first: low-pass filter or high-pass filter?

I want to do a RC bandpass filter can I use low-pass or high-pass at the beginning or does it have a specific sequence? First low-pass then high-pass, or first high-pass then low-pass?
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3answers
133 views

Sin signal from PWM

I wrote a program in order to use Pulse Width Modulation to simulate a sinusoidal signal. Added a low pass filter to get rid of the noise and the traces of it being a discrete signal. Added a half ...
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2answers
130 views

What do ripples in frequency response curve of filters depict?

I am trying to understand the frequency response curve of various types of filters (Butterworth, Chebyshev etc). The curves are shown here for reference : One thing I do not understand is what do ...
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1answer
54 views

Inductive filter vs capacitive filter: Which is better and gives less THD on the input side?

I have a generalised statement that total harmonic distortion (THD) on input side for input supply current is more for single phase diode rectifier with capacitive filter as compared to single phase ...
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2answers
63 views

Filter for radio receivers

I am in need of an intermediate frequency (IF filter) for somewhere around 200 Khz as intermediate frequency. However, I know just the bare minimum of filter design ( learnt all that a couple of days ...
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2answers
80 views

Order of resistor/capacitor in bandpass/highpass filter

Is there any particular reason to prefer one of these filter designs over the other? Theoretically, they are the same. Practically, does changing the order of the resistor and capacitor have any ...
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3answers
53 views

Correlation and filtering

I am trying to get an understanding of white noise and how it can be filtered out, etc. For that I'd like to understand correlation. What would the autocorrelation of white noise look like? If I am ...
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0answers
37 views

Need suggestions about a narrow bandpass filter design

I am now designing a narrow bandpass filter. Requirements are shown below: Center frequency is about 2kHz(10% flutuation is OK). The gain of center frequency is about 34dB(the higher the better,up to ...
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2answers
36 views

Measuring band-limited noise coming from an amplifier

I have a strain gauge amplifier and from my analysis, it will produce a low level of white noise above approximately 1kHz i.e. the power spectral density is flat above 1kHz. If I measure the output ...
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3answers
165 views

I need to remove 100mV of ripple out of my 12Vdc source. What size and type capacitor do I need?

I am building a very inexpensive power monitor. I need a clean 12Vdc power source for the current transducers. I currently have 100mV of ripple on the 12Vdc source i am using which is causing issues ...
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2answers
123 views

Inductor selection for obtaining a noiseless analog power rail

I interface an image sensor, and the design schematic for power supply is: How do I choose one from the available 3uH inductors based on the specs? I figured the maximum current and dc resistance ...
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1answer
69 views

Why is there a single high frequeny noise component in the output of an op-amp filter?

I have designed a lowpass filter of corner frequency = 50 kHz. According to TI's "Filter Design in Thirty Seconds", I build the schematic in LTspice as follows: The Op Amp LT1126 has following ...
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1answer
29 views

Conversion Process From Single-Ended to a Differential Filter

I have a single ended filter which is quite similar to the one on the following picture; My question is how to convert from single ended to a differential filter. Especially the inductors and ...
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1answer
68 views

RLC filters. How to determine band pass filter?

I have done question on frequency response of RLC it is easy to find whether a given circuit is high pass filter or low pass filter. But I am wondering how to determine for band pass or band reject ...
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1answer
56 views

Send digital data over same wire as analog data

I am trying to modify an existing circuit that I am able to send another digital signal over the same connection. My circuit is a so called "Partyline Intercom" which is based upon the schematics of ...
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2answers
213 views

Anti-aliasing filter closer to amp or ADC?

I'm designing a board with several amplified analog signals being fed into the internal ADC of a PIC DSP (dsPIC33FJ256GP710). Because of the board size/shape restraints, the analog buffers can't sit ...
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84 views

Low-pass filtering a 120 volt AC line to remove noise

I have active monitors (speakers) plugged into a 120 V line and they are picking up 120 Hz noise being generated by the TRIACs of the Lutron light dimmers in my house. The dimmers are on different ...
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2answers
61 views

Singnals, filters and power output

I have couple of questions: A square signal goes through a low pass filter and in the output of a circuit we get a sine. What happens there? Give a scheme? This is really weird, because, from what ...
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1answer
96 views

Combining LC filters

I would like to add an EMI filter to a high power LED driver. The datasheet of the driver suggests an LC filter for the power line as shown below. However I would like to use more than one driver ...
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1answer
58 views

Design steps for a choke inductor

I want to filter out high frequency noise on my power line. At first, I was considering to use an LC filter on the line; but then, I learned about choke filters are used exactly for this purpose. ...
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3answers
33 views

Transient analysis of filters inside allowed band

I understand that a zone pass filter will cut off portions of the signal in the cutoff zone, and allow or amplify the frequency parts of the signal in the allowed zone. Now lets assume a signal that ...
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2answers
81 views

Why should Q not exceed 1/2 on a 2-stage filter?

I am just starting on filters. I've seen on a tutorial that says 2-stage RC filter Q could not exceed 1/2. Could someone give some explanation?
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2answers
132 views

Generating a variable DC signal with PWM

I need to generate a variable DC signal from a given PWM signal. I read that this can be done by using first a low pass filter + op amplifier. The picture in the link can explain what I want ...
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2answers
54 views

Bandwidth of low pass filter

Say I have some low pass filter of the form: $$G(s) = \frac{a}{s+b}$$ How do I find the bandwidth? I know for example that with bandpass filters it's the difference between +-3dB of the cutoff ...
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2answers
79 views

High pass filter Using Inductor or a capacitor?

So I was thinking about making a basic Highpass filter. I was wondering if there was any reason to use an RL configuration as opposed to a CR configuration.
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1answer
114 views

How to make power supply to 434MHz receiver module more stable on RC car?

Following the recommendations I got on my last question about troubleshooting communications in my RC car, I probed the +5V power pin of my RF 434MHz receiver module with my oscilloscope. Below is a ...
2
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6answers
307 views

Cutoff frequency: exactly -3 db of power

I have a question which may sound strange, but still I'd like to ask community to explain that. Hope other people may find it interesting aswell. As we know, cutoff frequency is the one frequency ...
2
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1answer
173 views

USB 5v power filtering

I am creating a pcb that splits a single USB input into 3 outputs (one with data/power carried, two with just power), and I was wondering what is the best way to reduce noise on the power line as this ...
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6answers
1k views

What is the physical/electrical limit of audio quality?

A few days ago I was in a class about electronics on my study. The first lesson was an introduction into the main subject, bits, analog signals, conversion, etc. An example was asked by the teacher: ...
2
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3answers
108 views

Low-DC-resistance inductors?

simulate this circuit – Schematic created using CircuitLab I have a 5V DC source that passes AC noise (alternator whine, spark plug discharge through the smoke-lighter-to-micro-USB ...
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1answer
50 views

Integrated RC Filter Chip [closed]

I need an 100 tımes RC Low pass filter(6MhZ) for an application. There lots of another component in my layout. Do you know any RC low pass filter 'array' or similar chip ? update : I have 100 Ouptuts ...