Search Engine

155 Threads found on Differential Mode Output
I am trying to design the fully differential opamp. I put all the values according to mathematical calculation and put those values in simulator. After some simulation, some transistors are going to linear again against the calculations. I found a very high value of common mode voltage at output node. I tried all the means to get all MOSFETs (...)
Hello Can anyone help me in designing a common mode feedback circuit (CMFB). I have applied a 100mV DC common mode input voltage at the input of a differential pair with no Ac signal. My fully differential amplifier output common mode DC voltage is 456mV at one end and 450mV DC voltage on (...)
Yes, quite the same, I think: The CC transistor's input resistance calculation also has to consider the low input resistance of the CB output transistor parallel to their common emitter resistor, so it's the same as the common mode input resistance of the differential amplifier approach, and the CB transistor's output (...)
Hi common mode voltage on differential inputs is dc voltage offset that makes the transistors to get ON and be biased in active region , I think that's the same with your Vbias. rejecting common mode voltage means that the output voltage should not change depending on common mode voltage variations. (...)
Hi, I am using Cadence virtuoso and i have used a track and hold circuit where i take the output differential. In the next stage i need this output to have it in a single mode,which means i want to have Voutall=Voutp-Voutn. What is the way to do it so? Thanks
It helps to rid of noises rather than set to mid-rail of output? CMFB is absolutely required for a true differential amplifier to set the common mode output voltage which would be otherwise undefined. Depending on the differential feedback topology, it can also increase common mode (...)
I'm making folded cascode amplfier and common mode feedback circuit to bias output level. If i make output common mode level 1.75, then each my amplifier output is always almost 1.75v ,not average of two output level without changing my input voltage level. is my structure not right? (...)
Dear guys, Due to the periodic drift of the output CM level, the outputs (Voutp & Voutn) of a fully differential amplifier accordingly drift even with sufficient SR and UGB, as shown in the figure attached. This is the typical case. 128882 However, if we look at the differential signal (Voutp-
As mentioned by AMS012, the part marked replica buffer is just used to generate the required bias voltage for the main pseudo differential buffer. Basically you need to set the output common mode voltage to a comfortable level as supported by the ADC which the buffer drives. The high gain opamp sets the bias voltage so that the (...)
No, many applications want the output to put itself (and its common mode output voltage -is- its plain output voltage, by definition) where the input and feedback network say. Only in a differential output amplifier is the quantity of interest distinct from the output (...)
I am designing switched capacitor biquad low pass filter. I have some questions regarding the design. About my design : 1. Cutoff frequency = 1KHz 2. 65nm LP process 3. Clock frequency is 50K There are 2 integrator in my circuit. It is a second order filter. It is not fully differential. My question is How am I supposed to set dc out
Hi, additionally to Audioguru...there are different schematics: On post#1 there are three OPAMPs, On post#7 there are only two OPAMPs *** referring to schematic in post#7: 320V AC: is it 320V RMS or 320V peak? What frequency? then there is a voltage divider 2x270k to 2k7. Making the 320V AC input to 1.592V AC across the 2k7 (still un
For differential DAC output, if the output common mode voltage is 1V, the maximum output voltage is 1.5V, the minimal output voltage is 0.5V. if the A and B are the outputs of DAC, if (...)
Hi all, I am trying to build a simple fully differential op-amp just use VCCS. Here is the single-ended design I do in the cadence.121740 So I am wondering how can I build a fully differential op-amp model. I don't need transistor level design. I need a model so I can change gain, bandwith. It's for my project. So
I am a bit confused about the input/output impedance of the ideal_balun of analogLib. What resistance at the differential outputs is required so that the common mode input sees 50 Ohm? I use a port with Vin=50mV and 50 Ohm. When I connect 50 Ohm to the port and look at the amplitude it is exactly what expected: 50mV. (...)
When an Op Amp in running in a linear mode, the negative feedback forces the differential input voltage to zero. Linear mode means the output is not saturated. When using positive feedback, such as for hysteresis, the output is saturated.
To avoid DC magnetization of core , two cascaded inverting buffers capable of driving load in differential mode ; pls specify load and f.
I am able to find the settling time of single ended opamp by placing it in unity gain configuration mode. but now if I want to find the settling time for fully differential opamp then can it be simulated using cadence tool. If any one knows it then please suggest me the steps that will be helpful. Also you can mention the links.
i am having 20 x 4 alpha numeric display i want to extend 5mts from micro controller board how can i do this my lcd have the following pins rs,rw,en,d4,d5,d6,d7( 4 bit mode) my idea is converting micro controller output to differential using am26ls31 and then converting it to single point by using am26ls32 will this work for (...)
The hum is due to charger SMPS modulation of input AC and feedthru leakage capacitance to floating output of DC in either or both TV and phone. The common mode noise on unbalanced audio lines induces a differential noise. The solution is either use large CM ferrite choke wrapped with audio cable or clamshell type or easier, ground (...)