39 Threads found on edaboard.com: Schmitt Trigger Oscillator
As I asked in your previous thread: Which high speed OPs are available to you? You'll need at least 50 MHz bandwidth (GBW), better 100 MHz.
Other than for the integrator stages involved in your previous thread, the present circuit can also work with a fast comparator, which can be imagined as an uncompensated OP.
The most simple way
Electronic Elementary Questions :: 18.08.2011 04:40 :: FvM :: Replies: 4 :: Views: 1005
For the oscillator circuit to work it must be an inverting schmitt trigger. The 7414 family qualifies.
Electronic Elementary Questions :: 31.12.2011 01:40 :: BradtheRad :: Replies: 5 :: Views: 1239
Exactly, and changing the ratio between R8 and R9 in the circuit in post 5 will do that.
Yes. For a symmetrical adjustment range (50% +/-x %), we would connect R9 to -Vcc instead of ground.
Jasonc2 was referring to the same option as "asymmetrical schmitt trigger", but apparently didn't notice that it's already shown in post #5
Analog Circuit Design :: 08.08.2012 13:53 :: FvM :: Replies: 22 :: Views: 1639
I have a 6MHz noise sine wave signal from an oscillator which I would like to rectify. What would be a suitable schmitt trigger? Can they use analog input signals at this frequency? If so, can someone suggest a part number please.
Analog Circuit Design :: 11.05.2006 07:11 :: svensl :: Replies: 2 :: Views: 923
i have made a schmitt trigger using CMOS(conventional circuit with 2PMOS and 2NMOS, 1PMOS and 1NMOS in source follwer configuration) with VUTP(Upper Threshold point)=4V and VLTP=2V, with 5V power supply.
It is working vry fine
But wen i tried oscillator using this schmitt trigger(with (...)
Analog Circuit Design :: 21.09.2006 03:28 :: harry_madaan :: Replies: 4 :: Views: 1405
We can see some application material of xstal oscillator that they use
a schmitt trigger to follow the oscillator. What's the reason behind it?
For better noise? better interference immunity?
Analog Circuit Design :: 11.03.2008 10:21 :: OMEsystem :: Replies: 6 :: Views: 3495
Replace the schmitt trigger with a comparator. The voltage reference for comparator is a voltage based on bandgap.
Analog IC Design and Layout :: 17.02.2011 23:03 :: leo_o2 :: Replies: 12 :: Views: 1390
Hi, I once used an inverter in the MACH4A to 'clean up' a clock, with a couple of resistors to add hysterisis, effectively making a schmitt trigger. However, I'm not sure if what you are suggesting would be a good idea. You may simply have in your main schematic (design) an inverter buffer connected to two pins, but what you actually get may be 3
PLD, SPLD, GAL, CPLD, FPGA Design :: 04.03.2005 16:19 :: Buriedcode :: Replies: 4 :: Views: 1273
1.) You could try a NE555 timer IC. Requires a cap, and a couple of resistors to generate virtually any frequency you want. And this chip is cheap. I searched google for it, pictures:
2.) Even easier. Use a CMOS/TTL schmitt trigger inverter. Chips: 74HC14, 4093 (na
Hobby Circuits and Small Projects Problems :: 21.08.2005 18:50 :: Buriedcode :: Replies: 8 :: Views: 3364
when i connect the o/p of the relaxation oscillator (which has a capacitor at its o/p) to a schmitt trigger (which makes the amplitude control of the o/p triangular wave), the wave decays.
i think i'm having a very bad loading effect.
How can i solve this?
I've tried using a source follower with large source resistance (as
Analog IC Design and Layout :: 06.07.2006 12:57 :: Templar :: Replies: 0 :: Views: 824
I have to design a crystal oscillator at 26MHz and there is in the structure an amplifier, a control stage & a schmitt trigger . Any ideas for design?
Analog Circuit Design :: 25.03.2008 16:29 :: keoiuser :: Replies: 2 :: Views: 743
The most cost effective solution would be implement a simple R C circuit to slow the rise/fall. You could even make that resistor variable to adjust the frequency. I would recommend schmitt trigger logic though, as you wouldn't want any noise adding any 'false triggers'.
Hobby Circuits and Small Projects Problems :: 17.05.2009 03:00 :: mikal :: Replies: 1 :: Views: 1248
I am having trouble getting this to work with two stages, using one stage (3 LEDs) it works fine:
Hobby Circuits and Small Projects Problems :: 23.07.2009 21:36 :: Improviser :: Replies: 6 :: Views: 2153
Hello! Can anybody please explain to me how the schmitt trigger in both circuits and the voltage controlled oscillator in the link work? I couldn't figure it out especially the non inverting schmitt trigger part.
Here is the link from notes of IIT Madras:
Analog Circuit Design :: 01.09.2009 10:51 :: cebrax :: Replies: 1 :: Views: 1424
A 555 IC makes a simple square-wave oscillator.
A CD4047 IC makes an oscillator by adding one resistor and one capacitor.
A Cmos schmitt-trigger logic inverter or gate makes a square-wave oscillator by adding one resistor and one capacitor.
Electronic Elementary Questions :: 29.01.2010 14:59 :: Audioguru :: Replies: 6 :: Views: 1150
i designed a current mode OTA relaxation oscillator. the left part is OTA and the right part is schmitt trigger.
but i cannot get the oscillation in SPICE. i meant to give a 1 step voltage pulse kick start at feed back. but still cannot get the oscillation.
here is the schematic and plot of the
Analog Circuit Design :: 19.02.2010 05:20 :: chiu :: Replies: 2 :: Views: 600
I was making a high noise immunity divide by two for square wave. I didn't even chose to use the D type edge triggered CMOS flip flop 4013, for the sake of best noise immunity in noisy enviornment. I was getting stuck in the responses from the circuit.The schmitt trigger NAND gate 4093 was used in divide by two circuit. The circuit wasn't (...)
Analog Circuit Design :: 25.06.2010 09:51 :: umery2k75 :: Replies: 3 :: Views: 3585
I tend to use a slow triangular wave to test schmitt triggers for hysteresis.
Analog Circuit Design :: 27.08.2010 18:10 :: keith1200rs :: Replies: 7 :: Views: 2260
Hello! I am designing a quadrature oscillator as simple as possible (2 integrators, and when their value crosses a threshold makes the other one change sign of integration and simply it goes on and on). Ideally it's working. BUT when i add some delay on one of them or both, then, since there is no amplitude control, they go to infinite values and p
Analog Circuit Design :: 27.10.2010 07:36 :: geozog86 :: Replies: 0 :: Views: 488
Thanks for your reply.
I also not getting the LM324 transistor and 4093 schmitt trigger nand ic in ADS 2008,,,,,Can u tell me the equivalent.thanks
RF, Microwave, Antennas and Optics :: 18.02.2011 09:56 :: minhas_zubair :: Replies: 10 :: Views: 1025
The drawing (if not misleading on purpose) suggests a signal connected to the input wire/terminal. So in the general case, the circuit involves a short respectively a logic contention.
With suitable designed strength, a superposition of signals may be reasonable though. It could e.g. work as a memory cell, if driven by a tri-state driver.
Electronic Elementary Questions :: 29.08.2011 15:56 :: FvM :: Replies: 8 :: Views: 899
your 'comparator' is much too crude. use a proper comparator or schmitt trigger
Analog Circuit Design :: 18.07.2013 02:55 :: kam1787 :: Replies: 9 :: Views: 430
Hi, I usually end up writing loads when I ask for advice, I'll try to keep this short.
Right, I'm designing a fairly simple CPLD development board for a MACH4A CPLD. I would like to be able to have a wide selectable range of frequencies for the system clock without having a programmable PLL or thousands of jumper settings, trying to keep this a b
Hobby Circuits and Small Projects Problems :: 24.01.2005 02:01 :: Buriedcode :: Replies: 0 :: Views: 608
can use as comparator with +ve feedback.schmitt trigger or hysteresis comparator
Analog Circuit Design :: 27.07.2006 08:10 :: venkateshr :: Replies: 5 :: Views: 1360
schmitt trigger with integrator
The attached circuit is a pretty simple one (so is a little bit unflexible) but it generates a triangle and square wave with variable frequency and amplitude of ?Vcc). Let me know if you need something else.
hope that help,
Analog Circuit Design :: 16.10.2006 11:27 :: diemilio :: Replies: 8 :: Views: 1631
If you do not find 8038 similar ICs, try to find XR2206 function generator IC. The best is the MAX038 (out of production).
You can make function generator using some basic circuits as for example a wien bridge oscillator (for almost pure sinewaves) with a gang pot to control frequency. From this sinewave, you can derive square wave passing the
Analog Circuit Design :: 23.02.2007 06:05 :: rkodaira :: Replies: 7 :: Views: 1342
jaywant007, a reasonable analysis of a hypothetical circuit that no one should ever try building . I guess that it is meant to be some sort of a timer circuit, or is potatoe just having a good laugh. :D
Putting 12V on the input of a TTL IC is not a good idea, using the back leakage from an input to charge a big electrolytic capacitor is not a
Electronic Elementary Questions :: 16.06.2008 19:07 :: DrBob13 :: Replies: 19 :: Views: 1030
You should try differential signalling. And on the PLL side, you will need to square up the signal again by using a schmitt trigger - it's considered bad form to clock a flip flop with a slow edge.
But the best case would be to keep the PLL and crystal osc together on the die, because they share signals, and both need a clean supply voltage.
Analog IC Design and Layout :: 29.12.2008 12:29 :: electronrancher :: Replies: 1 :: Views: 695
Followings are TSMC 0.35 I/O PAD, I would like to know which one the the best choice for external clock signal generated by a 48MHz oscillator:
PDCHxSM : Very Fast schmitt trigger Non-Inverting Clock Input Pad,5V-Tolerant, Connecting VDD5V Power Ring
PDCHxSZ : High Drive, schmitt trigger Input (...)
ASIC Design Methodologies and Tools (Digital) :: 08.05.2009 03:08 :: Jerry Yau :: Replies: 0 :: Views: 677
I have a simple flyback circuit
why CD4069? because I had 25 of them.
input is 10-12V, output 250V.
not exactly isolated, as I connect the grounds for 12V and 250V thru a resistor.
The feedback is using a voltage
Power Electronics :: 22.11.2009 20:04 :: xaccto :: Replies: 6 :: Views: 2812
The circuit uses a TTL 74132 schmitt trigger as oscillator, TTL logic needs a 5V supply. The output stage is powered by 12V.
Analog Circuit Design :: 27.10.2010 15:11 :: FvM :: Replies: 6 :: Views: 712
Some FPGA's of Lattice have an onboard oscillator that you can approach and use in your design. However, these are not the 50ppm stable types. I once did an exercise to use the I/O and some gates in a MachXO to build an oscillator. The I/O was then programmed in schmitt-trigger mode. However, this feature has been disabled (...)
PLD, SPLD, GAL, CPLD, FPGA Design :: 13.07.2011 13:43 :: lucbra :: Replies: 12 :: Views: 1474
I always put a low-frequency oscillator ( schmitt trigger C and R ) and using its frequency, so as not to divide into millions
PLD, SPLD, GAL, CPLD, FPGA Design :: 04.08.2011 06:29 :: treqer :: Replies: 10 :: Views: 708
Hai i am not sure that how far i am correct but i am just making a suggestion.
You can use schmitt trigger
Analog Circuit Design :: 16.02.2012 22:59 :: karthikkrv85 :: Replies: 2 :: Views: 243
as you know if create a Current source with transistor and put the capacitor as load it only charge until Vc=VEE,doesn't take more voltage.
i want to demonstrate the capacitor integral voltage the increase with Current
Yes, that happens because no current source (or anything else) is a perfect. You may build a "perfe
Electronic Elementary Questions :: 18.05.2012 14:05 :: etmabreu :: Replies: 15 :: Views: 350
Your code is absolutely right dear..
I mean to say that... the pin RA4 of your controller is RA4 is a schmitt trigger input and an open drain output.
Open Drain output means, it is not having capability to drive the load connected at its output...
Just like the Port-0 in 8051 Micro-Controller's.. if you remember those...
So what yo
Microcontrollers :: 28.07.2012 05:45 :: xpress_embedo :: Replies: 6 :: Views: 561
i want to generate a 20kHz spwm for an inverter, so i need a 20Khz triangular and a 50Hz sin wave
but i don't now how to generate these waveforms.
anyone can help me please?
thanks for your help
This is too easy ! for triangle wave , you can easily use a relaxation oscillator , which is based on CD40106
Power Electronics :: 07.10.2012 17:41 :: goldsmith :: Replies: 5 :: Views: 570
In this circuit diagram two capacitor are connected with 20MHz crystal. I dont know what of capacitor these are. But I think this is a ceramic capacitor 0.1uf range. But i have no 0.1uf ceramic capacitor. My question is that can i use 22pf ceramic or 0.1uf electric capacitor instead of this??? Could anybody help me by giving details.
Microcontrollers :: 27.04.2013 23:23 :: goldsmith :: Replies: 3 :: Views: 271
for stability test use small signal model which is an integrator (consists of an ideal VCCS or CCCS plus one capacitor at output of the controlled source.)
if u need more accurate model for transent simulation consiering nonlinear behaveour of pll, make a vco with relaxation oscillator (an ideal schmitt triger plus a capacitor and a voltage cont
Analog Circuit Design :: 11.06.2004 06:28 :: goodboy_pl :: Replies: 5 :: Views: 1164