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47 Threads found on edaboard.com: Current Buffer Amplifier

## Frequency and current measurement for AC and DC Voltage using PIC16F1937

Assuming you are using 5V VDD and 5V as the ADC reference: 1. Use a 10:1 potential divider. If the current into the divider has to be very low (=high value resistors) follow it with a buffer amplifier. 2. Depends on the response time you need but simplest method is to convert the AC to DC and use a potential divider for the voltage. For the (...)

## problem with Simple OP amp circuit "output inverted"

Hi I am using a simple non inverting circuit to amplify the output of photo diode. The problem is that the output is always inverted, even that I am using non inverting amplifier. I have tried using unity gain buffer and current to voltage converter and get the same result as well. Is there any explanation for that? (...)

## preferred value of Rf and R1 resistances for inverting OPAMP buffer

It also depends on whether this is a voltage or current feedback amplifier. In general, a current feedback amplifier will use lower value resistors. So the real answer it depends on which type it is and what it's application is. There is no right and wrong answer although it would be unusual to see a resistor as low as 1 Ohm (...)

## buffer amplifier low voltage to higher voltage

Could you give me a hint to which transistors I need to uprate? hi, The choice of FET's will depend upon the Output current, the Bandwidth Frequency of the amp and the Voltage levels of the driving signal and Bias. Do you have a specification for the amplifiers performance.? E It would help if you posted your LTS asc files,

## What is octal buffer/Line driver 74HCT244? What does it do? and Explain its operation

Hi, What is not clear? Did you read the datasheet? Octal = eight times buffer = (current) amplifier line driver = it has enough power to drive long wires/traces HCT = High speed Cmos with Ttl level input; VCC = 5V, ViL = 0.8V, ViH=2V (about) datasheet gives the most reliable and precise information. Good luck

## How to design this BUFFER ckt.

I am in process of designing a CMOS CFA ( current feedback amplifier ). And this is one of the buffer ckt architectures I have found from technical papers by C. Toumazou. But I am not able to DC bias this ckt to provide sufficient operating current. Can somebody explain its functioning and sizing (W/L) procedure ? (...)

## current amplifier 20mA to 0-120mA

can u suggest a current amplifier circuit to convert 20mA to 0-120mA...the i/p voltage is 10 V... i require this circuit for amplifying square wave... please reply soon friends

## MOSFET capacitances - which ones matter most?

This depends somewhat on the close-in circuit topology. A low current common-source amplifier will see Cgd as its bandwidth limiter, Miller gain is the problem especially when the gate is driven by some weak current source. A common-drain buffer stage would see Cgd as a less significant penalty.

## question on amplifier phase margin requirement for current integrator

PM requirement is calculated with loop gain. For a closed-loop system with a closed loop gain larger than 1, OTA PM requirement is lower, i.e., can be lower than 45 degree. A buffer (closed gain is 1) has the worst situation and requires largest PM. I do not know how to calculate a current integrator loop gain since the i

## TTL switching between 2 analog signals

I'm trying to design a circuit with 2 analog inputs (+/- 10V max. range, output impedance <1Ohm, 10mA max. current) and 1 single analog output, and I need to switch between the inputs using a TTL signal. If TTL = high, then output = input 1, and if TTL = low, then output = input 2. I was considering using 2 switches of a DG211 SPST CMOS analog swit

## Analog Tristate Buffer

I understand a buffer amplifier followed by an analog switch as an analog tri-state buffer. It's e.g. utilized in sample-and-hold circuits. There are also OP-amps with disable feature. They set the output stage to high Z, but there's a certain leakage current, usually higher than with a true analog switch.

## Buffer from a CURRENT FEEDBACK AMPLIFIER

hey guys.... I want to make a voltage buffer... i.e. a unity gain amplifier from a current FEEDBACK help....

## Voltage Buffer, Current Amp, Drive DC motor

Hello all, I'm trying to figure out the best type of voltage buffer to use for a project I'm working on, where I am attempting to drive a DC actuator with a current of up to 300mA without frying the op amp non-inverting amplifier (simple LM741) I have for my DC signal (typical output current ~20mA). Given the many ways I (...)

## Impedance requirements

Hi, Can someone pls help me understand how do we decide whether we require a high or low impedance (both wrt input and output impedance) for a circuit? Is this logic correct - if the input current is to be minimum my input impedance should be low and if i want to deliver the maximum output current then my output imp should be high? Then how doe

## Three Stage LDO (Low Drop Out Regulator)

Hi All, I have been working on the following architecture for a three stage LDO. 85731 This is a Three stage LDO with a single miller capacitance compensation using inverted current buffers. The first stage is a basic pmos input differential error amplifier. The second stage is like a unity gain buffer. The third s

## what is the effect of adding current buffer in the op-amp?

I m designing a 2-stage miller op-amp. here in this op-amp M3-M4 are working as a current buffer. what is the effect of this current buffer on the amplifier gain? how does it affects the current distibution in the circuit? say if an o/p current of I8=800nA is flowing in the (...)

## Circuit for Voltage Follower / Buffer without opamp

Hi all! I'm facing a number of problems working with an opamp-involving voltage follower I've made. I wanted to know if there are any high output current voltage follower circuits that do not involve opamps? Humza.

## volatage to current converter

hello, i am designing a v to i converter, voltage input range is 0-5v dc, n the output current should range from 0-100ma. Please help me with this. please upload the necessary circuits. which opamp is best suitable for this application.

## Simple current summing circuit? Multiple currents in -> combined/summed current out.

Sorry, but the question is rather unclear. Seems that you are asking for a current multiplexer instead of the "summing circuit" addressed in the question title.

## help : i dont know how work one subcircuit in low noise amplifier with bipoar process

This part is just to provide a DC operation point, works like current mirror and use the buffer (opamp) to insulate the two BJT. it's not related to the independent temperature, actually there is no independent temperature current generated. ---------- Post added at 18:13 ---------- Previous post was at 18:01 ----------[/SI