1000 Threads found on edaboard.com: Op Amp Pspice
There is an element known as a current to voltage convertor in any version of spice.
please kindly refer to the following page to know how to use it in your simulation. You can maybe add a low pass RC network to the output to model the single pole roll-off frequency response of an I to V or rather a transimpedance op-amp!
Analog Circuit Design :: 03-16-2005 13:42 :: v_naren :: Replies: 1 :: Views: 1217
I'm doing a lab for my class and it says to look for an op amp with a GBW of 2*pi*10^6 = 6.28 MHz.
I suppose, you are looking for an opamp with a GBW=1 MHz equivalent to app. 6.28*10^6 rad/s. Right?
(Hint: In order to avoid misunderstandings like this, the radian frequency 2*pi*f should always be expressed
Analog Circuit Design :: 10-09-2010 03:38 :: LvW :: Replies: 2 :: Views: 986
An op amp?s recovery time measures how quickly it returns to a linear mode from a state of saturation. Does the op amp model in pspice include the effect of saturation recovery? Many thanks.
Electronic Elementary Questions :: 01-24-2014 03:06 :: powersys :: Replies: 7 :: Views: 392
I am trying to simulate the op-amp schematic diagram for a 741 and plot a graph of Power Supply Rejection Ratio v frequency. It is defined as 20 *log( change in dc supply voltage/ change in input offset voltage). Does anyone know how to work this out on the Cadence/ pspice simulator? Do the 2 differential input voltage sources need to be removed a
Analog Circuit Design :: 02-28-2004 18:50 :: ee01akk :: Replies: 1 :: Views: 2075
Does anyone know how to evaluate the PSRR of an op-amp practically on a simulator like pspice or Cadence?
PSRR=20*log(change in supply voltage/ change in input offset voltage)
How do I calculate the input offset voltage? Do the 2 differential inputs of the input stage need to be grounded to evaluate the output offset?
Analog IC Design and Layout :: 02-28-2004 18:55 :: ee01akk :: Replies: 2 :: Views: 7212
Try to sweep in frequency from 0 to 100kHz and obtain both gain and cut-off frequency. Cut-off frequency is no magic number. We agreed it is 3dB.
You can try in Spice or you can try to sweep in frequency in hardware.
I in school have a VI (in LabVIEW) which I can sweep in frequency the function generator any kind of wave. Makes things easier
Electronic Elementary Questions :: 09-16-2004 19:38 :: djalli :: Replies: 3 :: Views: 2006
I have a circuit diagram that is an active Op-amp low pass filter , but i don't know how to do the simulation of its frequency response using pspice.
Can someone teach me???
Use an sin input signal and ac amplitude) and measure ouputsignal => bode plot
Analog Circuit Design :: 03-10-2005 08:33 :: eda4you :: Replies: 4 :: Views: 1737
can I design high speed op-amp on orcad if yes plz,illustrate how to get cmos models of orcad and how to design if not which tool i can use
Analog Circuit Design :: 06-09-2008 01:34 :: abd_allah :: Replies: 4 :: Views: 857
Can anyone suggest what model of resistor, capacitor and op-amp to use in pspice for me to simulate under military temperature range(-55degree C to 150degree C )?
I need model which can vary according to temperature in pspice. Thanks.
Analog Circuit Design :: 12-03-2008 09:20 :: snee :: Replies: 0 :: Views: 534
help....how to find output voltage swing of fully differential op-amp
Analog Circuit Design :: 03-10-2010 04:49 :: nithinsmathew :: Replies: 1 :: Views: 3084
I've designed the attached bi-polar op amp. How do I calculate the max peak to peak output swing and max peak to peak input before distortion?
Analog Circuit Design :: 04-02-2010 13:16 :: laguna92651 :: Replies: 2 :: Views: 649
will the V+ and V- of the Op-amp influence my result?
Not particularly V+ and V-, but any property of the real OP that causes a deviation of the transfer function from ideal filter.
Hobby Circuits and Small Projects Problems :: 03-31-2011 08:21 :: FvM :: Replies: 2 :: Views: 1273
I didn't realise the model already contained the transistor information
The standard SPICE uA741 model provided by manufacturers is a hybrid model using a differential transistor input stage and behavioral modelling of most OP functions.
It's a common exercise in linear integrated circuits courses to simulate a transistor level u
Software Problems, Hints and Reviews :: 07-09-2012 13:39 :: FvM :: Replies: 3 :: Views: 1538
Currently I'm working on the LDO reg. pspice macromodel but I have some concerns about the output noise modelling.
After studying some papers on Op-amp macromodels I was able to obtain fairly good match between the Output Voltage Noise Density Measurements and Simulations in 10Hz-1MHz bandwidth.
(The noise source was placed in series wi
Analog Circuit Design :: 07-26-2012 04:27 :: darki_ :: Replies: 0 :: Views: 271
please some one tell me the logic of designing a simple op-amp circuit in pspice. where the output voltage will be the square root of input voltage
Microcontrollers :: 09-16-2012 12:24 :: JUBAYER :: Replies: 1 :: Views: 663
how would be the method to simulate the thermal drift in an op-amp with the SPICE macromodel?
I pretend to simulate the -40 to 85 ?C behaviour of the circuit and i think the op-amp macromodel doesnt have any parameter dependant with the temperature.
Analog Circuit Design :: 03-09-2013 20:45 :: Draytek :: Replies: 2 :: Views: 482
i want higher frequency op-amp designs. anyone has them? thanks a lot
Professional Hardware and Electronics Design :: 05-16-2002 11:24 :: djalli :: Replies: 2 :: Views: 915
How comparator input overdrive and propagation delay is related ??
are you considering an op-amp with internal compensation? if the op-amp input stage is saturated, there is no more dependance on the input signal amplitude due to slew rate limitation and compensation capacitance.
If you consider an open loop or hyster
Professional Hardware and Electronics Design :: 05-23-2003 05:06 :: trifilinux :: Replies: 2 :: Views: 2398
Anyone seen a circuit of to do a "dirty" but cheap RS-485 receiver with an OP-amp? Need it for a cheap quick test of balanced data lines.
Professional Hardware and Electronics Design :: 04-26-2003 13:44 :: MrEd :: Replies: 3 :: Views: 1428
There is a famous book on the subject
Author is Graeme, Jerald G
Title is Photodiode amplifiers: Op amp Solutions
RF, Microwave, Antennas and Optics :: 05-30-2003 20:49 :: flatulent :: Replies: 1 :: Views: 1081
I also found this kind compensation, the third stage output use a capacitor to the first stage negative input, and the third stage is a pmos series with two series resistors. the common terminal of resistor connect to the first stage.which kind of op amp is used to multi voltage of the positive reference voltage. who can help me about this compen
Analog Circuit Design :: 03-13-2004 02:07 :: rambus_ddr :: Replies: 19 :: Views: 4604
if you have simulated your circuit (e.g using spectre) and have the necessary signals in the waveform display window --> start calculator --> click at the wave button --> select a wave in the waveform window --> the waveformId will be displayed in the calculator --> than you can execute nearly every operation with this waveform (e.g subtract a
Analog Circuit Design :: 02-29-2004 16:14 :: hqqh :: Replies: 11 :: Views: 9150
i am building an IC TESTER which aongst its various functions has to test for proper functioning of op amp 741.How can i test it? i am using PIC for testing of various logic ics as of now.
Analog Circuit Design :: 03-28-2004 07:43 :: sukanya :: Replies: 2 :: Views: 4119
Because in most cases there will be no advantage in doing so. Remember that it is usually preferable to operate operational amplifiers in an inverting mode since distortion due to common-mode gain is minimised.
Analog Circuit Design :: 04-12-2004 17:53 :: Beetroots :: Replies: 10 :: Views: 12754
you can write a ideal opamp with AHDL/verilog-A in Cadence by yourself, or you can find it in a AHDL library which provided by cadence.
Analog Circuit Design :: 05-03-2004 06:45 :: piao :: Replies: 15 :: Views: 12435
I agree with santhoshv78, you need a bias circuit rather than just supply a ref voltage! However, you can make it simpler by using transistor acting like active resistor by connecting Gate with Drain!
The main problem on your circuit is some of the transistors are not in saturation! Check your netlist@output file and track the problem transistor
Analog Circuit Design :: 08-08-2004 22:37 :: guamak_menanak :: Replies: 8 :: Views: 2977
Is anybody aware of a site i can go to download a fully diff. op amp component that i can import into spice?
Analog Circuit Design :: 08-14-2004 03:15 :: cjupiter :: Replies: 1 :: Views: 702
Try to see the book :
IC Mask Design - Essential Layout technique
The layout of an op-amp is reviewed in detailled with all tips and tricks !
Analog IC Design and Layout :: 08-24-2004 19:51 :: okguy :: Replies: 5 :: Views: 2672
I was assuming that this was the resistor from the output to the inverting input. The gain will be proportional to this resistor with the other one fixed in value. If this is a load and not a feedback resistor, the comments about output swing hold and the gain should not be affected.
Analog IC Design and Layout :: 08-31-2004 20:58 :: flatulent :: Replies: 7 :: Views: 3396
What is a low noise op-amp?
Analog Circuit Design :: 09-03-2004 03:24 :: zahrein :: Replies: 2 :: Views: 651
An Opamp is the wrong choice for trying to supply higher voltage for LED operation because it isn't intended to provide the current you will need.
There are special purpose IC's that do exactly what you want. One of my favorites is at the URL below. Search using Google, and you will find others by other manufacturers.
Electronic Elementary Questions :: 09-12-2004 14:07 :: House_Cat :: Replies: 2 :: Views: 4265
Tiny Low Power Operational amplifier with Rail-to-Rail Input and Output
LMC8101 - improved supply current, maximum supply voltage and output current.
Analog Circuit Design :: 09-14-2004 13:11 :: dainis :: Replies: 3 :: Views: 1964
This can be throught. OP amp's sometimes latchup when output is driven "over" negative supply rail.
Electronic Elementary Questions :: 10-09-2004 15:12 :: Borber :: Replies: 20 :: Views: 2086
i found there was no folded cascode op amp completely composed of bipolar ?!
i have only seen folded cascode op amp completely composed of cmos ,or composed of cmos and bipolar,
but i have never seen completely constructed by bipolar.
Analog Circuit Design :: 11-02-2004 11:10 :: chmhero :: Replies: 5 :: Views: 1148
Hi guys .. is easy to see that analog is NOT MY BREAD ... (Topology what am i thinking??) .. I need an analog circuit using an OP amp rail to rail single supply 3V
i've been thinking to use a MCP601 .. i need a diferential filter with a cutt off freq of 70khz .the signal i need to filter has a DC component ( well between +3 and -3 V) so i need to
Analog Circuit Design :: 11-30-2004 12:23 :: eltonjohn :: Replies: 3 :: Views: 941
Many books existed for rail-to-rail opamp design such as "Low voltage CMOS Operational amplifiers----Theory , Design and Implementation" ----by Satoshi Sakurai and M.Ismail
Analog Circuit Design :: 12-08-2004 04:18 :: xwcwc1234 :: Replies: 5 :: Views: 1750
Hi every one
I have dsigned a circuit with lm741 but its high input noise and its low slew rate is so bad for my there an op-amp like lm741 but with lower noise and higher slew rate.note that is footprint must be same as 741.
Analog Circuit Design :: 01-21-2005 09:55 :: mhamed :: Replies: 1 :: Views: 1563
I know that to reduce input current in for CMOS Op amp, the designer can increase the resistor value or/and increase the output transistors multipliers.
But, how about reducing the current consumption in BJT Op amp?
Analog IC Design and Layout :: 02-03-2005 03:43 :: lucky8 :: Replies: 3 :: Views: 1024
i need advice. i'm trying to modify the 741 op amp.
i know that if i increase DC gain, then my cut-off frequency and phase margin will definately go down. is there any other way that i can do to balance the trade-off?
i hav set my spec:
1. DC gain = 118dB (6dB increment)
2. cut-off frequency > 5Hz
3. phase margin > 55 degrees
Analog IC Design and Layout :: 02-15-2005 22:13 :: lucky8 :: Replies: 1 :: Views: 1206
At least, you can try AC analysis to check the gain phase margin. It is the basic check for a opamp.
Analog Circuit Design :: 02-25-2005 05:58 :: kwkam :: Replies: 8 :: Views: 983
For op-ams, we generally care about voltage gain. So whether you need an op-am with high or low output impedance depends on the loading impedance compared to the op-am's output impedance. When loading impedance is low, a buffer will be required to transfer high op-am output impedance to low.
Analog Circuit Design :: 02-27-2005 02:20 :: lakeoffire :: Replies: 10 :: Views: 1198
How to do the pole-zero anylysis of Telescopic Cascade op amp as shown?
Analog Circuit Design :: 02-25-2005 05:39 :: Alles Gute :: Replies: 17 :: Views: 2250
An ideal symmetric opamp surpress the common mode noise components from the bias. If the opamp is used in circuits which have to reject some big signals the common mode noises get modulated by the big signal and distort the wanted small signal. So in addition to AC small signal noise optimisation run a period noise analysis with a blocking signal.
Analog IC Design and Layout :: 02-28-2005 04:31 :: rfsystem :: Replies: 2 :: Views: 869
what is minimum input voltage which LM741 op-amp can amplify when used as an amplifier
I tried to find this in datasheet but there is maximum value but not the minimum.May be its given in the form of some other parameter or i am unable to understand so plz help.
actually my pressure sensor MPXM2202AS can give me output proportional (...)
Hobby Circuits and Small Projects Problems :: 03-16-2005 13:50 :: Munib :: Replies: 3 :: Views: 5936
The symptons you mentioned in the email seems to be related with the improper bias of the OTA, which also causes the systematic offset at your transfer curve. You can find a lot of literature (for example, Ken Martin's Analog Integrated Circuit Design) to cover the design of folded cascode OTA and proper choice of the input branch versus output bra
Analog Circuit Design :: 03-19-2005 15:01 :: willyboy19 :: Replies: 2 :: Views: 1316
There are two inputs in operational amplifier.
If you apply your measured AC on "+" input of op. ampl.
You can add offset voltage to "-" input.
( Of course "+" voltage applied to "-" input shifts op. amp. output "negative".)
You should also take into accoout the amplifier gain.
(add 1 V offset if op (...)
Analog Circuit Design :: 04-03-2005 09:44 :: AndrzejM :: Replies: 3 :: Views: 1771
Hi. Yes, the opamp would work, but you might want to define a new "ground" for input signals that is slightly above the real ground to make sure the opamp's transistors remain biased. Try googling "single supply opamps".
Analog IC Design and Layout :: 04-18-2005 13:55 :: arebee :: Replies: 2 :: Views: 708
I recently need to design RSDS circuit , and would like to know where I can get information from. And how do I get start in circuit creation.
I just know RSDS a little , and just wonder RSDS reciever is created by OP-amp or differential amp.
please correct me if I am worng , and love to have any suggestion from you guys.
Analog IC Design and Layout :: 04-19-2005 10:42 :: wesspower :: Replies: 0 :: Views: 510
To Analog IC helper :
I recently design OP-amp , and got very big issue with current mirror in OP-amp circuit. Please download the circuit ( that is attachment) , Within the white square, that is the simple current mirror to provider current for different amp (1st stage) .
My problem is that I set 40u A in i1 , (...)
Analog IC Design and Layout :: 04-20-2005 04:44 :: wesspower :: Replies: 1 :: Views: 805
designing an Opamp for single or symmetrical power supply is the same. Your methodology does not change.
Analog Circuit Design :: 05-10-2005 03:31 :: Humungus :: Replies: 5 :: Views: 870