137 Threads found on edaboard.com: Filter Constant
To reject the unwanted signal better use notch filter or band stop filter
RF, Microwave, Antennas and Optics :: 05022010 13:35 :: kspalla :: Replies: 4 :: Views: 1425
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
Analog Circuit Design :: 04272010 23:34 :: sweethomela8 :: Replies: 11 :: Views: 6486
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.
Elementary Electronic Questions :: 03092010 10:14 :: umesh49 :: Replies: 9 :: Views: 2516
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 (...)
PLD, SPLD, GAL, CPLD, FPGA Design :: 02172010 01:02 :: mersault :: Replies: 1 :: Views: 843
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?
Elementary Electronic Questions :: 12062009 19:41 :: ppp1262 :: Replies: 9 :: Views: 5416
Put in an RC low pass filter with the required RC time constant and frequency response.
Professional Hardware and Electronics Design :: 07082010 23:05 :: deepuj :: Replies: 1 :: Views: 1598
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
Digital Signal Processing :: 09212009 07:08 :: cherishnguyen :: Replies: 1 :: Views: 1074
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 = Aexp(t/RC) )
time1=RC ln(0.1A/A)
time2=RC ln(0.9A/A)
response time = time1  time2 = RC ln (9) ~ 2.2RC
Analog Circuit Design :: 08012009 08:55 :: wpchan05 :: Replies: 6 :: Views: 6960
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
Elementary Electronic Questions :: 06262009 09:10 :: tyassin :: Replies: 1 :: Views: 2329
A first order filter has a time constant, starting from second order it hasn't.
Analog Circuit Design :: 03192009 17:38 :: FvM :: Replies: 1 :: Views: 3923
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
Digital Signal Processing :: 02162009 08:07 :: rramya :: Replies: 2 :: Views: 1120
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
Digital Signal Processing :: 02042009 08:56 :: stiltz :: Replies: 0 :: Views: 932
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 30mils wide lines.
what is the formula to calculate the length of the haipin resonator?
RF, Microwave, Antennas and Optics :: 01272009 03:12 :: danesh :: Replies: 1 :: Views: 1218
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 (...)
Electromagnetic Design and Simulation :: 10242008 06:15 :: Felis_Silvestris :: Replies: 3 :: Views: 4886
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 (...)
Analog Circuit Design :: 10262008 02:41 :: whitewiz :: Replies: 6 :: Views: 1029
dear lhlbluesky:
In my design,
PTAT: to combine bjt to output a reference voltage for common mode voltage.
constantgm: for gm filter and AGC.
mpig
Analog Circuit Design :: 10102008 14:39 :: mpig09 :: Replies: 2 :: Views: 1160
LC filters are by nature narrowband and may be preferred in such (narrowband) applications. Additionally, the gain is not quite constant at the inband 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.
Elementary Electronic Questions :: 09252008 20:45 :: saruman1983 :: Replies: 3 :: Views: 1523
Depend on the application.
I could see tow application where constant gm is important
1. OpAmp
2. gmC 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 (...)
Analog Integrated Circuit (IC) Design, Layout and Fabrication :: 03272007 08:14 :: rfsystem :: Replies: 14 :: Views: 21136
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 lowfrequency mixing product.
For example:
VCO: 2GHz  3GHz
LO: 2GHz

After mixing and lowpass filtering you get 01GHz. All required components you can get at MiniCircuits.
For example, for hobby (...)
Analog Circuit Design :: 09152008 17:16 :: rfmw :: Replies: 3 :: Views: 3354
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
RF, Microwave, Antennas and Optics :: 09072008 13:22 :: danesh :: Replies: 3 :: Views: 2277