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155 Threads found on Differential Mode Output
When I created and simulated a differential amplifier with an active load, for some reason I'm getting an incorrect DC graph. All the mosfets are biased in saturation, does anyone know what the problem could be? I have attached the schematic as well as the dc graph. 9835498355
I know that it is approximately zero. Can anyone help me how it become zero from small signal analysis. What is the final gain equation from small signal analysis?
Fully differential opAmps always need a CMFB. Here, the CMFB stage is already integrated: M41 - M46 . The common mode feedback works from M46 into M36 , whereas M43 to M34 as well as M44 to M33 provide positive 1/N feedback to the output stage.
1.) Input common mode range short v0 and vin+ pin, choose dc analysis and sweep vin- from 0 to vdd.. plot vin- and v0 2.) output resistance connect vdc from analoglib at v0 pin, choose dc analysis and sweep vdc form 0 to vdd, plot v0 and I(vo) from that calculate R 3.) differential gain connect vdc and give ac (...)
If common mode levels are not well defined, It may appear as offset and makes unwanted signal variations at the output... The high gain of the differential amplifier makes this offset into large change in the output... it also affects the original replica of the input signal... and also causes the DC parameters of the (...)
I am designing a 2 stage Miller compensated OTA. I have problem in fixing the output common mode voltage. There was no problem when i designed a differential output OTA, as a CMFB loop ensured proper output DC voltage. But when i tried to design a single ended OTA, i dont get the desired common (...)
Hi ahmad1954, just for a better understanding of the differential pair: Your output characteristics would exhibit better symmetry - even if you apply one single input voltage only - if you reduce the common mode gain by increasing the common emitter resistance. An ideal diff. pair has a current source in the emitter path (resistance (...)
hi I am doing my course project on clock and data recovery. In that in phase aquisition loop phase detector is implemented by current mode logic.The problem is when i gave phase detector error output signal to v-i converter(differential amplifier is one of stage used for voltage to cuurent converter) it is switching in only one side (...)
For the Circuit shown in figure 1 it is required to know the minimum allowable output fig 2 it is the instructor solution for it as there
I am designing a folded cascode opamp with a single-ended output and that has both NMOS and PMOS input differential stages (for wide input common mode range). All the circuits I see, however, have a differential output. Is the bottom design a correct implementation of a single-ended
You are surely going to loose some benefits of differential output , 1- PSSR will be bad because the DC part output ( which is now a signal instead of output CM ) will change with fluctuation in current source of I/2 due to supply noise 2- The CMRR will also be effected to a lesser extent because the (...)
Hi, you cann't make source follower for differential load in that way. This load resistance making your device asymmetric. I think that you must enter common mode feedback from output to inputs of current sources, something like this: 87595 Below shows waveform on which dVin changes from -500m to +500m 8759
Hi all, May I know why the following circuit output common mode voltage is not 0.9
dear all, now i found a problem in design fully-differential sc amplifier used in pipeline adc: my supply voltage is 1.2V, and all of the common-mode output of op are 0.6V to max the swing. however, from the schematic we can know that the input common-mode voltage is been setted at 0.6V, but the input stage maybe work (...)
I wanted to design an current mode operational amplifier with differential input and differential output as a part on my project. I have referred a few papers for the same but what I find missing in the papers is the biasing circuits required for the current mode op-amps. I need any reference that can (...)
Hello, I am looking for a differential resistive DAC in literature/papers, which - has single Vref reference voltage - common-mode of output differential signal is CM -and CM > Vref I didn't find any information/example/paper. Could you please show me such examples? Thanks.
Sounds like you are referring to a particular IO standard, e.g. differential SSTL. It's a voltage referenced standard that requires connection of termination resistors to a reference voltage. Termination requirements are quite different for IO standards, also the chances to achieve reliable signal quality in single ended operaton. You should be mor
I am simulating a fully differential OTA for a class project. I have the basic specs where I would like them (like gain,BW,PM). But, when I run my transient sims, I am seeing Vout and Voutb are not symmetric. Both are pulled up to about the common mode votlage of 1.1V and then are clipped. My differential output looks (...)
1. I have read somewhere that while in the holding mode, the input common mode voltage of the differential amplifier is equals to output common mode. Does that necessitates the vcmin range should include vcmout? If not what will happen? During hold mode the amplifier is active. In this (...)
Hi I'm designing a CML buffer (3.3V supply) 100 ohm differential termination I wonder how to have a 2V output common mode and 1.5 Vpp differential output swing any one have suggestions thanks.