1000 Threads found on edaboard.com: Advantages Of Folded Cascode
How to determine transistor size of folded cascode ota(gain=80db,fu=30Mhz)?
Analog Circuit Design :: 02-25-2004 20:47 :: rose_song :: Replies: 5 :: Views: 3409
folded cascoded Amplifier
1. High Gain
2. Improved Bandwidth
3. High Slew rate
4. High stability
5. High input impedance
6. The folded cascode Opamp is useful for moderately low supply voltages, at the cost of some extra current, but has limited performance in sub 1V applications, as well (...)
Analog Circuit Design :: 03-29-2010 23:58 :: ammadupm :: Replies: 12 :: Views: 9222
i am designing a folded cascode amplifier,with high gain and low current required,when i ever i run a monte carlo simulation in cadence while only mismatch is selected,the DM gain and CM gain vary a lot,means mismatch is really bad,can anybody tell me how to improve the mismatch of the whole circuit???thanks
Analog Circuit Design :: 10-28-2009 09:20 :: chichi :: Replies: 11 :: Views: 2266
what is the advantage of pole at folding point in the folded cascode ?I read that the capacitance of folded cascode is greater than the capacitance of telescopic cascode the telescopic cascode is more stable than cascode ?
Analog Circuit Design :: 03-10-2012 07:12 :: manikprabhu :: Replies: 0 :: Views: 423
I designed a folded cascode amplifier,I want to get 1vp-p ((vin=sin(12x ))swing from diff out of opamp.
shoulde first pole of folded cascode biger than 12x????????????
Analog Circuit Design :: 09-30-2012 16:50 :: paramis :: Replies: 0 :: Views: 292
Here is my folded cascode fully diff amp without CMFB. I apply two sine waves, and i get output as shown. Even without the CMFB circuit, shouldnt i get a much larger voltage swing then the one i have achieved. If i should what could i be doing wrong. My W\L ratios correspond with Johns and Martins dimensions out of their book "Analog IC design" Any
Analog Circuit Design :: 07-30-2004 12:49 :: cjupiter :: Replies: 3 :: Views: 990
What is the advantage of folded cascode opamp compare to telecospic
cascode opamp and olso its application? Thanks in advanvce.
Analog Circuit Design :: 09-14-2004 04:19 :: surianova :: Replies: 6 :: Views: 2910
I was just wondering about the noise of the folded cascode amp.And i have following query(question).
1)Why the noise of bottom transistor in cascode is nondominant contributor towards the overall noise.
2) How to go about reducing the oveall noise of amp.
3) What is the contribution of the tail current noise (may be the flicker) (...)
Analog Circuit Design :: 08-22-2005 01:38 :: rvenigal :: Replies: 1 :: Views: 1599
I have done an amplifier design by using folded-cascode configuration. I found that the supply voltage for folded cascode is about 0.6V, however when the same amplifier by using cascode configuration need 1.8V supply voltage.
Can anyone talk about
1. why folded (...)
Analog Circuit Design :: 03-16-2007 11:36 :: electronics_sky :: Replies: 16 :: Views: 2563
what are the advantages and disadvantages of folded cascode amplifier??
Can be designed rail to rail input voltage.... low output swing... high output impedance.....what else??
Analog Circuit Design :: 04-25-2007 06:39 :: ashishjain_1000 :: Replies: 6 :: Views: 6344
For an OPAMP how to decide the tail current of folded cascode stage 4 particular slewrate..bcoz this gain stage drives the o/p stage not the load (CL) i am confused can any1 plz explain me...
Analog Circuit Design :: 08-13-2007 12:55 :: rampat :: Replies: 0 :: Views: 905
I want to design a folded cascode amplifier with gain>70dB.
I can design it with gain=62db.please help me for increasing gain.
Analog Circuit Design :: 12-31-2007 08:49 :: royayeboodan :: Replies: 7 :: Views: 1108
In the book Analog Integrated Circuit Design by Ken Martin,it says :
The second major reason of the use of cascode stages is that they limit the voltage across the input drive trasnsistor.This minimizes any short-channel effects
can any one explain me the above line?
Analog IC Design and Layout :: 06-25-2009 02:36 :: bharatsmile2007 :: Replies: 0 :: Views: 860
- consider changing the output stage cascoded NFETs (M4-M13, M12-M14) into a mirror configuration, this will increase gain by a factor of two and also provide other advantages
- the output stage current will be defined by slew rate constraints, which in turn depend on the output capacitance
you can still increase the output resistance by increasi
Analog IC Design and Layout :: 08-04-2011 00:00 :: dgnani :: Replies: 13 :: Views: 2074
I have attached a picture of a folded cascode amplifier with class AB push pull stage.
My question is regarding the SLEW time of the amplifier. During the 'internal slewing' when the compensation capacitors CM1, CM2 are being charged up, what is the status of the M4, M4C, M8A, M9A, M2C, M6 ? Do these mosfets operate in saturation or triode regi
Analog IC Design and Layout :: 01-08-2014 07:12 :: cmos_ajay :: Replies: 0 :: Views: 187
I could use your opinion on a problem I am facing with my op-amp design. It's single stage folded cascode. Trouble is I'm not able to get the current of 25uA (am getting only 21uA) to flow in the two folded cascode branch.(spice file attached) I have changed the bias voltages and sizes but without (...)
Analog Circuit Design :: 03-19-2005 04:56 :: kart339 :: Replies: 2 :: Views: 1330
As in the attachment,
the circuit uses the feedback to generate the stable current Id, which will be mirrored .And the mirrored Id through resistors can get the reference voltage used in ADC.
I used common folded-cascode opamp just like the circuit in razavi's book.
my questions are
(1)how to simulate the stability of this circuit?
Analog Circuit Design :: 03-14-2006 09:21 :: icx :: Replies: 1 :: Views: 1300
what is the significance and necessity of 'folded' cascode amplifiers?
and when is a bjt cascode used and when a mos cascode is used? which is a better one?
thank you in advance,
Electronic Elementary Questions :: 12-06-2006 05:08 :: amriths04 :: Replies: 4 :: Views: 824
Now, I am just about to layout folded cascode for the firs time in my life
How do i place components? these transistor`s size is almost 1um/1um and i use 0.35um
so, too small to use common multifinger and common centroid at the input stage
Considerin about critical matching
How I place components?
Analog IC Design and Layout :: 04-11-2007 02:05 :: yousoo :: Replies: 1 :: Views: 1163
Has anyone wrked on the following architecture ? Cud u please tell the design approach for this..And also how to take care of THD in this design..
Analog Circuit Design :: 08-21-2007 02:02 :: rampat :: Replies: 3 :: Views: 2995
I designed two Gm-C low-pass biquad filters by using only folded-cascode and telescopic-cascode OTAs for the each biquad.
THD of the telescopic-cascode based filter is much much more than of folded-cascode based filter.
I was expecting telescopic-based would have less THD!
I wonder (...)
Analog Circuit Design :: 07-24-2009 19:25 :: karakurto :: Replies: 0 :: Views: 505
1)I am designing a high frequency integrator based on folded cascode topology, but i am a little confused grasping the concepts of folded cascode...e.g the number of transistor stages in cascode structure, biasing, current steering etc...if some one can provide me with some material covering the (...)
Analog IC Design and Layout :: 11-04-2010 00:24 :: samiurrehman :: Replies: 6 :: Views: 1229
HI i am new to the analog based circuit design.. I have been designing folded cascode OTA for 9-bit 200MSPS pipeline ADC in 90nm CMOS technology with the following specifications
power supply =1v
dc gain= 62db
unity gain b/w =1.162Ghz
phase margin =68.38deg
But when i simulate the following ota for dc gain using cadence tool, im nt able to g
Analog IC Design and Layout :: 04-29-2012 08:06 :: nari reddy :: Replies: 1 :: Views: 624
so for following specs, I am trying to use folded cascode followed by common source amp.
i did the fully differential mode folded cascode n got around 76dB gain with all other specs in line, my question is how to add CS Amp at out of folded cascode?
1. 2 CS for each output of DM (...)
Analog IC Design and Layout :: 12-05-2013 03:41 :: xaptar :: Replies: 2 :: Views: 238
I saw this picture of folded cascode amplifier somewhere in a slide lecture. The problem is that the writer didn't give any explanation about subblocks in the picture.
As you can see, there are blocks:
- DC shift level
- Compensating DC shift level
- Driven current generator
I have searched a lot for how these blocks work but found nothing.
Analog IC Design and Layout :: 05-22-2014 15:33 :: anhnha :: Replies: 3 :: Views: 324
What are the advantages and disadvantages of PMOS input folded cascode vs. NMOS input cascode amplifier? PMOS has smaller flicker noise. What else?
Analog IC Design and Layout :: 10-09-2004 00:03 :: tumati :: Replies: 7 :: Views: 3716
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: 1159
It seems to me a bit strange to compare a two stage architecture to a single stage architecture.
Generally talking, single stages offer lower gain, limited output swing and external stabilization compared to two stages architectures.
As for the folded cascode architecture also offers some advantages:
- High Gain
- High BandWith
Analog IC Design and Layout :: 01-21-2005 09:45 :: Mline7 :: Replies: 12 :: Views: 6869
I am designing an op amp (folded cascode - gain boosting - cmfb). In the folded cascode opamp, there is no bias current source (unlike the telescopic design). So how do my cmfb feed in it?
Analog Circuit Design :: 11-15-2005 23:24 :: vvchan :: Replies: 3 :: Views: 1385
I have seen gain boost amplifier which increases the output impedance by a factor of A of auxilliary amplifier.
i have seen all the implementations in differential output op-amp.
I am looking for the topology of single ended output gain boost folded cascode amplifier .
Can somebody suggest any document/paper.
Analog Circuit Design :: 04-30-2006 04:15 :: pulkit shah :: Replies: 3 :: Views: 2672
Hi every body
i am looking for books or tutorials for design procedure of folded cascode with fully differential amplifier gain boosting, i will use it to design pipeline ADC
Analog Circuit Design :: 06-18-2006 00:37 :: wael_wael :: Replies: 11 :: Views: 2784
How to increase phase margin of a single stage folded cascode single ended output amplifier.
Analog IC Design and Layout :: 11-11-2006 12:27 :: tshankar501 :: Replies: 3 :: Views: 1064
I am in the myst of prove how a folded cascode configuration can help to improve the cut off frequency of a CMOS transistor. I need formula to proof how this is happened?
Anyhow, formula or intuition explanation or any other positive explanation are appreaciated.
Thanks a lot!
RF, Microwave, Antennas and Optics :: 03-08-2007 13:20 :: electronics_sky :: Replies: 4 :: Views: 613
what is the very simple trick to increase the cutoff frequency of a folded cascode.
Analog Circuit Design :: 05-30-2007 15:41 :: AZALBE1975 :: Replies: 2 :: Views: 1340
I am designing a folded cascode with systematic offset spec less than 100uv. Attached is the schematic of the circuit (biasing transistors have the same dimension as those in the ota ). the max systematic offset at this moment is 600uv. can anyone give me some tip on where to go to reduce this offset?
Analog Circuit Design :: 06-02-2008 18:06 :: heverlee :: Replies: 2 :: Views: 1200
i read that cascode structure has advantages on high reverse isolation and reducing the effect of Cgd
plz explain them, how are they possible??
can anyone give me some material on this?
Analog Circuit Design :: 06-26-2008 07:54 :: bcdeepak :: Replies: 4 :: Views: 1098
Can anybody tell me where I can find a book or pdf to calculate PSRR of a folded-cascode opamp with pmos input?
Electronic Elementary Questions :: 04-23-2009 12:33 :: mialee :: Replies: 0 :: Views: 1038
The advantages have been correctly pointed out. This does come at the cost of reduced speed. But then for smaller technologies gain is a significant issue.
Analog IC Design and Layout :: 06-27-2009 11:08 :: seej :: Replies: 5 :: Views: 1665
i am designing a gain boosted cascode folded opamp and i have done with my
main amplifier of 40dB and 300MHz. right now, i am doing the gain boosted ota.
the paper that i have read says that the input and ouput of the gain boosted
opamp are to be set, marked as red in the figure.
Analog Circuit Design :: 09-21-2009 05:20 :: ella1923 :: Replies: 1 :: Views: 2885
I am doing project on Cadence Tool.. that is Recycling folded cascode Amplifier... Please send the Schematic Circuit of the Recycling folded cascode Amplifier with input and bias values... Please forward the details.
Analog Circuit Design :: 04-19-2010 02:24 :: sai143 :: Replies: 0 :: Views: 972
please tell me how to calculate the biasing voltages of conventional folded cascode amplifier.. i am attaching my circuits.. also tell me how to calculate the device sizes of mosfets... please reply.....
Analog Circuit Design :: 05-04-2010 23:33 :: sai143 :: Replies: 2 :: Views: 1121
What is the range of Gain, Output Swing, Speed, Power dissipation and Noise in Telescopic, folded cascode, Two Stage and Gain Boosted topologies of operational amplifiers?
or suggest me where to find there ranges.
its very urgent. kindly reply to this post.
Thanks in advance.
Analog Circuit Design :: 07-16-2012 14:14 :: amit.31 :: Replies: 1 :: Views: 389
I want to design a CMFB for fully differential pmos-folded cascode.
I use this circuit,but I don't know how determine size of transistor?
output diff swing:2v p-p
Analog Circuit Design :: 09-01-2012 12:48 :: paramis :: Replies: 5 :: Views: 394
Here is your standard fully diff. folded cascode op amp. Im using 0.18um technology, 1.8V supply. Im not getting the correct open loop output. My open loop gain is way tooo low. Cant even get a gain of 1. I know that all transistors should be operating in the saturation region. How do i go about setting all transistors to be in saturation? Do i set
Analog Circuit Design :: 08-08-2004 05:33 :: cjupiter :: Replies: 8 :: Views: 2994
The following folded cascode is taken from Gregorian book. Why is the aspect ratio for the second expression given as (3+2√2)(W/L)11? Does it have to do with mobility of NMOS and PMOS?
Analog Circuit Design :: 12-16-2004 04:21 :: ccw27 :: Replies: 2 :: Views: 1169
How do I make a comparator using a folded cascode? Where to connect the possitive feedback?
Analog Circuit Design :: 12-16-2004 05:11 :: Tom_Sawyer :: Replies: 9 :: Views: 2444
what is an folded-cascode CMos OP-amp
do v have folded-cascode NMos OPamp also
Electronic Elementary Questions :: 12-25-2004 15:16 :: aman :: Replies: 3 :: Views: 2369
Q2. Total bias current in folded cascode case is required higher than in simple cascode stage to achieve same performance. why???
Analog Circuit Design :: 02-25-2005 01:22 :: Analog_IC :: Replies: 5 :: Views: 1511
I am new to this forum, hope someone could help me
i am designing a fully differential folded cascode opamp with gain boosting technique for pipeline adc.
i have used pmos input stage, so what would be the input stage of gain boost opamp. does the gain boost opamp can be a simple opamp, or it should also be a folded (...)
Analog IC Design and Layout :: 03-19-2005 04:00 :: B Swapna :: Replies: 3 :: Views: 1937
Can anyone tell how to start desiging a folded cascode. For a particluar speed, settling time how to calculate the output current. I f we knwo the Iout then I think we can use the formula and then find the W/L of each transistor.
But what are the consideration has to be taken to Find Iout ?
Thanks in advance
Analog IC Design and Layout :: 04-25-2005 06:00 :: dream_taker :: Replies: 5 :: Views: 1138