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# Opamp Bandwidth

218 Threads found on edaboard.com: Opamp Bandwidth

## Opamp specification in reconfigurable pipelined ADC

Hello, I am designing a reconfigurable pipelined ADC with varing sampling rate and resolution. Can anyone tell me how the opamp specifiation of individual pipeline stage would vary with resolution and sampling rate of ADC? Cheers

## [Moved]: opamp ac simulation circuits

Hi everybody How can I obtain gain and bandwidth and phase margin in folded cascode opamp? Does anybody has a circuits model to implement it in hspice? Thank you.

## resistor selection in inverting-noninverting amplifier

Your opamp is very simple and is missing a voltage gain stage so its voltage gain will be low. Its supply voltage and operating current are extremely low. Its bandwidth and slew rate are very high for an opamp. The resistor values must be fairly low for operation at the VHF frequencies due to stray capacitance, but the resistor values must (...)

## How to relate the time constants, opamp bandwidth and settling time?

Hello guys, Is someone here that could explain me how to relate the parameters mentioned in the topic, when designing an opamp? For example, design the opamp to have a very small error in the settling time and relate that to how many time constants are needed for that small error, say 0.01%? I think it is related to the opamp (...)

## editing dVce time constant

Hi, i want to measure dVce/dt, for that i used a differential amplifier(i need Vce too), after that i put a RC circuit to get dVce problem is, dVce peak value change too fast, ADCs are soo expensive. changing RC doesnt help because output of the opamp change to fast. Circuit looks like on the picture. i didnt use peak detector, because i

## Creating a variable wien bridge oscillator

The lousy old 741 opamp was designed 48 years ago. Use a modern opamp instead that has a bandwidth of 100kHz or more. To change the frequency of a Wien Bridge oscillator you must change both resistors at the same time. My Wien bridge oscillator goes from 10Hz to 100kHz using a TL071 audio opamp that has low noise, low (...)

## Is it feasible to use Vgs somewhat less than Vth ?

Hi, In an opamp, we can set the input-pair MOSFETs to be in Sub-threshold region of operation. To what extent can we put them in sub-threshold?...like, can we use (Vgs - Vth) negative? As I searched in forum posts, people say they use (Vgs - Vth) ~ 100-200mV which makes the MOSFET near subthreshold..but is it feasible to use a Vgs so

## Feedforward: What am I missing?

Hi, I wanna build 2-stage opamp with feedforward compensation. Let me start with the basics: Let's assume I have two ideal transistors with intrinsic gains a1,a2 and certain GBW1,GBW2. Let's assume both parameters are comparable and I connect them in series then I have gain a1*a2 and bandwidth sqrt(sqrt(2)-1)*GBW1 = 0.64*GBW1. Nothing will be

## input signal conditioning for DSO

Dear all, I'm a little bit "rusty" with signal conditioning so, with the aim to review analog design, I would like to design a signal conditioning circuit for an oscilloscope input. I've not great expectations with bandwidth (<5Mhz) but I would like to input max 400V signals DC & AC with 1MOhm || 50pF employng opamp or bjt. Is there any guidan

## Why is the bandwith of a current conveyor larger than opamp?

I heard that the bandwidth of a current conveyor is higner than opamp because it work at open loop.I don't understand what's the reason. The open loop 3dB BW of an opamp is 1/RoCo,where Ro and Co is the res and cap at the output node and the BW is wider in closed loop operation. why a current conveyor has larger BW at open loop condition?

## How to remove ripples from Chopper stabilized Opamp?

When we will design a chopper stabilized amplifier, due to offset, some ripple of the same frequency as the chopping frequency will be generated at the output. How many ways are there to remove this ripples? I am in search of some useful material regarding this.

## Folded cascode opamp design procedure using cadence

I need folded cascode design step by step, i want to implement it on cadence 180nm suggest me the procedure or ieee paper through which I can design Folded cascode opamp using cadence

## to make op amp gain more bigger with fixed bandwidth

You do not make the output resistance "more bigger" (higher). Instead for more gain you make the negative feedback resistance higher. An opamp has a frequency compensation capacitor to reduce the gain at high frequencies so that its phase shift does not cause oscillation when negative feedback is applied then at high gain the bandwid

## Op amp Common Mode Feedback Design

... the relation between the gain of the CMFB circuit versus the gain of the op-amp. Same for the gain bandwidth product, should the CMFB gain & GBW > op amp gain & GBW? or the opposite? 1. Gain: The CMFB's DC gain has no direct relation to the opamp's DC gain. It should be just large enough to compensa

## [Moved]: linear voltage to current converter

Do you know how to build a low power linear voltage to current converter? The voltage to current conversion needs to to very high precision, like 10bit resolution. This opamp based V/I is good, but the opamp will consume large power consumption. Since I need a fast response Voltage to Current, the opamp needs to be large (...)

## [Moved]: Problems in simulation noise of amplifier

Hi everyone. I am using Cadence IC5 to simulate a 2 stage opamp noise. What I want is to find the corner frequency where 1/f noise equals thermal noise. The problem is that from "direct plot->main from->noise" I can see the 10dB/decade roll till 1kHz, then the power begins to keep decreasing with 30 dB/decade and never stop. I think the problem

## Wideband decoupling switching load (DC-GHz range)

However the bandwidth of the opamp is limited to about 70MHz and also the output impedance increases from there on. A more appropriate description would say, the output impedance is continuously rising beyond 1 MHz. And not explicitely specified in the datasheet, but obvious by circuit analysis basics, mostly inductive. Bypassing t

## -3dB frequency estimation for basic OpAmp configurations

Hi all, I would like to ask you a basic question, how to estimate -3dB cut-off frequency of basic opamp circuits like inverting amplifier, non-inverting amplifier and unity gain amplifier(buffer). Thank you, David

## Two stage op amp Vs folder cascode

Two stage opamps are normally used to enhance the gain of opamp as one stage can not provide high gain. However, there is a compromise, higher the number of stages, higher the number of parasitic poles, Therefore, it is more difficult to stabilize the opamp and to have wider unity gain bandwidth. Folded casocode single (...)

## Op-amp slew rate - bandwidth relation?

The voltage gain of an opamp circuit also determines the bandwidth because an opamp rolls off high frequencies to avoid oscillation at a high frequency when negative feedback is added. The datasheet for the TL07x opamp shows a bandwidth to 100Hz when the voltage gain is about 32,000 times, to 1kHz when (...)