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137 Threads found on edaboard.com: Filter Constant

PA and linearity question

To reject the unwanted signal better use notch filter or band stop filter

5mhz differential low pass filter (passive)

I'm trying to build a passive low pass filter (fo=5Mhz) with R/C values on the output of a differential buffer.. ------(differential+)-------RESISTOR------------------------(differential+ receiver) | CAPACITOR

How to calc value for R and C for low pass filter

I have forget the reference but it is assumed that time constant of the low pass filter circuit should be atleast 3 times of the period of input pulse.

problems with clocks (i think)

Hello everybody.. I'm doing a FIR filter in a spartan 3e FPGA, but doesn't work as I want. the problem is a little strange. every time that I generate a bit file, the behavior of the system is different!... for example... I generated a bit file. I charged it. I put, as input tho the filter, a constant value and the (...)

Rc time constant, low pass filter?

Hello, For a first order RC low pass filter we have (wikipedia) ω=1/τ , τ=R*C, 3db cutoff we also have Z=1/(ωC) for any capacitor giving Z=R at cutoff However if Z=R then Vout=Vin*0.50, which is not 3db What am I doing wrong?

How to generate a pulse with rise/fall time about 1us?

Put in an RC low pass filter with the required RC time constant and frequency response.

How Digital Control Ossilator make output in-phase?

Hi all, I have read through some doc about ADPLL. It containts 3 parts: PFD, filter, DCO. The main part DCO will adjust the output based on input frequency. Let say: i want to generate output fo= 2fi from reference input freq, fi= 100Mhz. The DCO will do some stuff in order to generate fDCO=200Mhz, and in this state, fDCO = fo, w

Response time of RC filter

But t=2.2RC is a time constant which is not equal to response time of a filter I think what biff44 said is based on a 1s order response (eg y = Aexp(-t/RC) ) time1=-RC  ln(0.1A/A) time2=-RC  ln(0.9A/A) response time = time1 - time2 = RC  ln (9) ~ 2.2RC

Time constant in an RC circuit or low pass filter question

Hi A time constant is the samme in active inplementation. It is still your components that determine the freqeuncy response. With active filters you gain some advanteges like loading the filter without changing its filter response and avoid inductors. Regards

How to calculate the time constant of 5 order RC ladder ?

A first order filter has a time constant, starting from second order it hasn't.

design LPF given i/p signal its sampling freq, req o/p

Hai everyone, I have an i/p signal x = 1 +0.5* sin(pi*t) where t = , basically a signal sampled at 100 Hz. I need to filter out the d.c. component i.e. get 1 as a constant output so for which I have to design a low pass filter. can any one tel me how to design low pass filter in MATLAB Thank you

Transient duration of PLL

Hi, Can anybody explain for me why 1st order PLL has smaller transient duration than 2nd order loop for the same value of loop noise equivalent bandwidth?? This is the model I am trying to simulate in matlab . Here F(Z) is is a digital filter. What I mean by first order loop is F(Z) = A i.e. any constant(obtained from loop bandwidth) and

Stripline Length - length of the haipin resonator

Hi guys im designing hairpin filter. one of the book that i have refered written the length of the quaterwave rsonators as: The length of the hairpin resonators is found to be 860 mils by using the effective dielectric constant, ε eff = 1.88, for 30-mils wide lines. what is the formula to calculate the length of the haipin resonator?

How to design a complementary diplexer in ADS? plz help

For a diplexer the LP and HP filters are designed differently than ordinary filters that are designed to work in a system Zo (a constant Zo). At the common node of a diplexer each filter must work properly while looking into the impedance of the other filter that is also in parallel with the system (...)

Constant gm filter design

I need to design constant gm filter to put it in front of preamplifier in order to get constant gain at the 100MHz frequency. Unfortunately, there is no good textbook in the library. It is so appreciated if you recommend any publications or books relating to constant gm filter design. Thank (...)

What's the difference between PTAT and constant-gm reference?

dear lhlbluesky: In my design, PTAT: to combine bjt to output a reference voltage for common mode voltage. constant-gm: for gm- filter and AGC. mpig

Use of LC filters below 1 MHz

LC filters are by nature narrowband and may be preferred in such (narrowband) applications. Additionally, the gain is not quite constant at the in-band frequencies comparing to RC or RL filters.So, I believe the kind of the application determines which kind of filter is better to be used.

Constant Gm bias circuit?

Depend on the application. I could see tow application where constant gm is important 1. OpAmp 2. gm-C filter The second use reference matching architectures so individual constant gm is less important than C/gm time constant matching to a clock source. For OpAmp constant gm reduces the spread (...)

Help me with MAX2620 VCO design

Make a VCO in the GHz range, that easily covers 1GHz of bandwidth. Then mix its output with a constant LO and filter out the low-frequency mixing product. For example: VCO: 2GHz - 3GHz LO: 2GHz ----- After mixing and low-pass filtering you get 0-1GHz. All required components you can get at Mini-Circuits. For example, for hobby (...)

Parallel Coupled Strip line filter

hi guys, i wanted to design parallel coupled filter. i having trouble in calculating the width and the saparation between two strip line. Obtained: Dielectric constant ,er= 2.55 Thickness, H=0.5inch Even mode impedance=82.53ohm odd mode impedance =37.6ohm appreciate your help. thanks