Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [rail-to-rail]

35 questions
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What does "rail to rail output opamp" mean?

Context: I have a very similar problem to the one exposed here, and in the best rated answer (by Olin Lathrop), he says we need a rail to rail output opamp. My question: What is a rail to rail opamp? (In what characteristic does it differ from a…
CaptainBleuten
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Rail to rail +12/-12 V square wave generation with microcontroller

I need to generate a +/-12 V square wave, +/-0.4 V tolerance is allowed. The purpose is to drive the pilot signal of an electric vehicle level 2 charger, for those curious. EDIT (clarification): what I'm trying to design here is the EVSE controller…
jamarju
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Biasing a DIY current feedback opamp

For a personal project, I'd like to make a discrete current feedback opamp. Here's a simplified schematic: The question is about how to bias Q3/Q4. For a nice class-AB output, the sum of both Vbe's should be constant. In a common collector output…
bobflux
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Unused Opamp Termination: How does it cause increased current consumption?

Usually the following configuration for unused opamps is said to be troublesome, even for rail-to-rail input & output (RRIO) opamps. Nevertheless, it is attractive because it requires no additional components. simulate this circuit – Schematic…
tobalt
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How does a common-emitter rail-to-rail opamp output stage work? Is there a discrete example?

I'm reading an article about how a rail-to-rail opamp works. The materials from Maxim and Analog Device all mentioned that, in a conventional operational amplifier, the output stage, in its essence, is a pair of NPN/PNP forming an emitter follower.…
比尔盖子
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How do I see if an op-amp is rail to rail using only datasheet?

If I have a data sheet or part of it, how can I see if an op-amp is rail-to-rail using only the numbers? For example, only using the image below, how can I see if input and/or output is rail-to-rail?
バカです
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Why is my op amp railing?

So I have a LM358 Dual opamp. I only care about the first op amp, the second I just have set to put out 12V to keep it from floating. The the first is reading in feedback from a 1k potentiometer from 10-0 volts. The voltage divider knocks it down…
Ih8th3c0ld
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Are there any single supply OP amps with negative supply voltage?

I learned that basically the only difference between a "single supply" OP amp and a dual supply one is that the former can drive much closer to the negative supply rail. Furthermore if I understand correctly, if you enable a "single supply" OP amp…
Shenpai Yajulight
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Understanding Summation of Currents in a Rail to Rail Differential Stage

In order to understand rail to rail OpAmps I consulted a (german) textbook. There, I found this principle schematics: So far I understood, there are two complementary differential input stages (T1, T2 and T3, T4). When a differential signal is…
MichaelW
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Simulating PMOS differential amplifier in Cadence

I am studying about rail-to-rail opamp design and I am trying to recreate the Itail vs Vgs (in this case input common voltage) curve from the link bellow (pages 5 and 6): https://mixsignal.files.wordpress.com/2013/03/689-604rail2rail.pdf I am having…
San
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High voltage op amp rail generation

I'm using two ADHV4702-1 high voltage op amps for a project. They are configured as a current sink with a class B output amplifier (with some fixes for the crossover distortion). I already have a +/-12V supply for other parts of the circuit (two…
OM222O
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What is the difference between differential rail-to-rail, push-pull rail-to-rail and rail-to-rail OPAMPs

I'm loking for an rail-to-rail OPAMP to my project. I need a OPAMP that fed by a 12V and a -5V power supplies can generate an output voltage near these values, at least, near the positive 12V, the value of the negative source is not needed to be…
Daniel
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How can I determine whether this is a "rail to rail" opamp from its datasheet?

I know that rail to rail means that the opamp output can have a swing upto its power rail voltages. So for a rail to rail opamp lets say if the supply test condition is +-12V, I would assume that the output swing can reach upto +12V or down to…
floppy380
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Comparator circuit undesirable fluctuations

I have designed a comparator with hysteresis and rail to rail operation and my output depicted in figure1.The inputs of the comparator is a sine wave signal and a triangular waveform as shown below.Vdd is 1.2V and the transistor technology is 65nm.I…
vl123
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Rail to rail amplifier analysis problem

Can someone help me to understand what we expected in the output(Voutn,Voutp) of the circuit of figure 1?I have searched for months a lot of books but I can't understand the operation of the rail to rail stage.Why someone to use it? The rail to rail…
vl123
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