A circuit or sub-circuit that as accurately as possible preserves the voltage characteristics of a signal while providing additional current. Typically used in situations where a circuit cannot drive the load that is presented to it.

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3answers
78 views

Are there better alternatives for these buffers?

I'm building a circuit that extract the DC component of an input signal, ,divide the DC component by 5, and finally add 2.5V it. Here is the schematic of the circuit (the last op-amp is to invert ...
2
votes
1answer
86 views

This guitar piezo opamp buffer lacks any sort of bass, why?

My preamp in my acoustic guitar died after I put the battery in backwards. I need to replace it, and fast. Piezos have incredibly high output impedance (5+ mohm) so a buffer circuit is used to knock ...
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4answers
537 views

Is this clamping voltage divider for a high-impedance input a good, robust design?

I have an AC input as follows: Can range from ±10V to at least ±500V continuously. Runs from roughly 1 Hz to 1 kHz. Needs > 100 kΩ of impedance on it, otherwise its amplitude changes. May ...
4
votes
1answer
69 views

Is it safe to separate the power supplies for sensor, buffers, and ADC?

In the LT1054 datasheet it talks about needing a bjt to avoid pulling the VOUT positive with respect to GND (datasheet page 5 Vout (Pin5): http://www.linear.com/docs/2309). Now I am powering an ...
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0answers
13 views

Current 'buffer' for low power hall sensor

For a low power device I'm currently working on, I need some sort of current buffer. I'm planning on powering my device with a 4-20mA current loop, which leaves around 3.5mA of current I could use. I ...
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1answer
36 views

Voltage follower with a pair of matched FETs

I am studying for an exam and as a part of a question I have to explain biasing and operation of the voltage follower that uses two matched JFETs in the following arrangement: I am not sure that I ...
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2answers
77 views

CMOS tri-state buffer internal structure

I was trying to understand the CMOS tri-state buffer internal structure with logic gates... The image is similar to this one: Anyway, I'm not understanding the logic I think something is escaping: ...
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0answers
23 views

Commond drain high input voltage

I'm currently designing an opamp without active loading. If in the end I want to add a buffer so that my gain isn't highly dependent on the load , how can I implement this buffer ? Also the supply ...
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0answers
43 views

Voltage to Current converting with LM675 Power Op Amp from TI

This is the circuit that I have in mind. The op amp receives voltage signal from a buffered DAC (its maximum load is 50 kOhm) and output a current with frequency of 1 kHz and amplitude of 1 A. The ...
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2answers
105 views

Real life output impedance of a Unity-Gain OpAmp Buffer circuit

How can I estimate the output impedance of a unity-gain opamp buffer circuit? With an ideal opamp the impedance would be \$0 \Omega\$, but we don't have ideal parts. E.g. the datasheet of the AD8226 ...
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5answers
2k views

Op-amp inverter followed by buffer. Why?

In a schematic I've been trying to understand I came across this sub-circuit: It's an op-amp inverter directly followed by a buffer. VIN comes from a DAC in a microcontroller and this circuit ...
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0answers
31 views

using the AD8475 as a single ended output

simulate this circuit – Schematic created using CircuitLab I am putting together my schematic and I am trying to figure out if I can use the AD8475 as a single ended output buffer. ...
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1answer
33 views

Unexpected output from 74AC244 buffer

On our board we use 74AC244-SO buffer to isolate microcontroller pins from outer world, buffer is shown on the picture below. Just for the purpose of test I've simple SPST switch attached between one ...
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vote
3answers
76 views

Storage for High Power High Current Pulse

I am currently developing a high voltage, high current amplifier for an EMI test pulse generator. I have been able to generate the pulse in 5V level so far and I am now trying to boost the pulse (in ...
2
votes
5answers
192 views

How to remove spikes from switching transistor?

I am building a steady current source which delivers steady current (0-20mA) to an LED. The brightness of the LED (current) is controlled through a potentiometer's voltage and a voltage follower as ...
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3answers
112 views

Why does this circuit produce a static noise?

I was just designing this Common emitter transistor amplifier this morning. simulate this circuit – Schematic created using CircuitLab I have removed the input in the circuit ...
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2answers
80 views

make a buffer balanced

i am still new to electronic and i probably have a stupid question.. i am trying to build a buffer for a piezo microphone following the project on this site: ...
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2answers
168 views

Pull up on output pin of Buffer SN74HCT245

I am using SN74HCT245 Buffer operating on VCC=3.3V. So, I am getting 3.3V at each output pin of buffer (B1 to B8). But if I want to drive a load with 5V input, what options are available to me by ...
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0answers
56 views

74HC4051 Analog multiplexer settling time

I have simple schematic for multiplexing single ADC input to multiple analog inputs, made from LMV934 buffer and 74HC4051 analog multiplexer. The problem is, after selecting desired analog input, ...
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votes
1answer
81 views

Diode circuit fed with voltage follower doesnt work

I have a ldr circuit. In order to drive other circuits i connected a LDR circuit to voltage follower. I want to see at the output either nearly 0V or 9-12V. At Ltspice it works, but at the blackboard ...
1
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2answers
84 views

buffering large DC signals

Is there a way to buffer a large DC signal accurately? I would like to measure a voltage that can go from 0 to 50VDC, with 16 bit accuracy (so down to the mV level at the highest voltage, and µV ...
5
votes
1answer
205 views

Buffer for 5V, 500ps to 10 ns pulses

I am trying to make a buffer for short, 5V pulses. The pulses are negative (form 5 to 0 V) and last for 500 ps to 10 ns (Half maximum, full width). The load is capacitive, around 50pF, and as close as ...
5
votes
2answers
168 views

can I use any OP AMP as buffer

I am still studing OP-AMPS and I was playing around with voltage follower/buffer configuration, the very basic diagram connecting the inverting input to the output directly and put some voltage on the ...
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2answers
85 views

Unity gain op amp gives static, incorrect output

I have the circuit shown here: where I'm using a switching regulator (not the linear 78xx shown) to provide me with 5V to power an Arduino and a little more circuitry that the Arduino is monitoring. ...
0
votes
1answer
24 views

multi channel buffer

What is necessary to drive two op amps (tl071 for instance) from one piezo guitar pickup, which of course is a very high impedance source? Result being, one very high impedance source creating two ...
0
votes
1answer
74 views

op amp emitter follower buffer offset

Hi, I'm using an emitter follower op-amp buffer with LM6132 and PN2222A. I'm expecting almost an exact follow?, as simulated with multisim. However, I'm getting an output offset of around 50mV at ...
2
votes
1answer
126 views

In a simulator, outputing +/-5V peak AC through bridge rectifier then opamp buffer gives 5V DC output… software error or does this really happen?

In a circuit simulator I'm using it shows that if I run an AC voltage through a bridge rectifier and output that to a op amp buffer, the voltage at the input of the opamp (and hence the output) is the ...
2
votes
2answers
115 views

Difference between tri-state buffer and inverting tri-state buffer

Is there any significant architectural difference between non-inverting and inverting tri-state buffers? In what cases would it be advantageous to use one over the other? To me they seem like the same ...
3
votes
2answers
101 views

Is there any bidirectional IC with on/off state?

I need a bidirectional IC with on/off state. In on state, IC should have very small impedance on the line. In off state, IC should provide very high impedance to isolate the bus. It's for an ...
5
votes
1answer
125 views

Simple way to invert a tristate output

I am looking for a simple circuit to invert a tristate output from a microcontroller, hopefully using only BJTs. What I mean by this is that the truth table would look like: ...
3
votes
1answer
322 views

how to split audio with buffers?

I am split an audio signal coming from an op amp to both a line driver buffer and a VU meter buffer, as shown in the schematic. My trouble is in determining the correct placement and value of ...
1
vote
2answers
113 views

How do I get a low impedance current output from this circuit?

I am learning about the VI characteristics of diodes, specifically nonlinear resistor applications. The circuit in this question is used as an example, but the question applies to any high to low ...
3
votes
3answers
176 views

Lower impedance for AC coupled darlington amplifier?

I have a problem I can't quite figure out. I essentially want to "buffer" a 50mVpp audio signal to drive a 16 ohm load. I preferably want to use primitive components so I thought that maybe a ...
0
votes
1answer
115 views

Voltage follower/Buffer circuit as summing amp

Is that possible to use a voltage follower/buffer circuit as summing amp? In history, what kind of circuit was used for summing amp before people started to use those inverting summing amp circuit? ...
0
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2answers
105 views

How much current can this 74HC245 handle on each output pin?

How much current can this 74HC245 handle on each output pin? Is it 20mA, 35mA, or 70mA? I don't understand what the difference between output current, output clamping current, and supply current is. ...
1
vote
1answer
150 views

Different ways of using UART

What is the difference when you send/receive data via Linux serial device file like ttyS3 and when you directly read/write from/to UART FIFO buffers? What situation is more safe and better? How ...
1
vote
2answers
113 views

Opamp AB Class Current Buffer

I am trying to design 100W (100V - 1A) Opamp Current Buffer with unity voltage gain. I will use PA441 or LT6090 opamp. Apex published a circuit for this amplifier. Please look at page 3 from the link ...
2
votes
1answer
93 views

Small stepper, simple driver

It's a very small stepper at 18 ohm resistance per coil(2 of them) (4 phase). I got: stepper in the picture, L9110, LM358, arduino. I used an L9110 with the arduino. The stepper moved where it was ...
1
vote
0answers
174 views

spi fan out - sn74AHC244 - not working

I'm a complete beginner at this so please don't overlook any silly mistakes that a complete beginner may have made. I have a home-brewing project, where I am attempting to hook up multiple MAX31865 ...
0
votes
1answer
138 views

Trouble splitting off LFO signal to drive LED

Background: I am trying to build a very simple noise box that doesn't need to be tuned to 1V/Oct or anything special. It simply has one VCO, two LFOs, and a VCA. The circuit is powered off of a dual ...
1
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2answers
94 views

Unexplained voltage drop in input clamping & buffering circuit

I'm designing a circuit consisting mainly of 74LS series logic. I am clamping and buffering several input signals using a zener diode and a 74HC7014 Schmitt trigger buffer. A relevant excerpt of the ...
2
votes
2answers
119 views

How improve temperature sensitivity of HP 721A DC Power Supply voltage reference?

I have a sentimental affection for my HP 721A DC Power Supply: http://hpmemoryproject.org/pict/wall_a/anim/721a_q90/viewer.htm Rugged, dependable, and roughly as old as I am, it is also pretty ...
1
vote
2answers
424 views

Help for a 5V to 15V level shifter

I'm using FPGA DE2 board cyclone II from altera (for PWM generation) to control a DC chopper via ARCAL 2108 driver ;The problem is that the FPGA GPIO output gives a 3.3V but the driver is +15V input . ...
2
votes
2answers
685 views

How do I implement a tri-state buffer for a vector in VHDL?

I want to implement a tri-state buffer for a input vector, triggered by an enable vector, where every bit of the enable vector enables the corresponding bit of the input vector. Something like this ...
1
vote
1answer
509 views

A simple FIFO buffer in verilog

I have decided to implement a FIFO buffer in verilog (for fun). Here is my primary prototype you can say : It will consist of a register bank or memory. Each register will be of size N and there ...
0
votes
1answer
110 views

Buffer to have ( 5V-->15V) with DAC conversion

I'm working on a project of a digital control of a DC/DC converter (DC/DC converter which I need to control with an FPGA). My DC/DC(IGBT) is wired to an ARCAL 2610 driver. My question is: My ...
0
votes
1answer
135 views

Verilog mux using a clock

I'm trying to get a simple piece of logic working: on the positive edge of the clock the output should always be 1, on the negative edge, the output should be the value of a provided input. I've ...
0
votes
1answer
165 views

Need a voltage follower buffer for a tube, how do I calculate and select a mosfet?

I'm finishing up a design here: https://123d.circuits.io/circuits/852190-jan-6418-vaccum-tube-valve-preamp which is a preamp for an instrument. First, let me know if anything stupid pops out at you ...
0
votes
4answers
213 views

Making a LM1458 work as a Unity Gain buffer with an input of 0 to 12v output to a digital voltmeter

Making a LM1458 work as a Unity Gain buffer with an input of 0 to 12v output to a digital voltmeter. When I connect this cct to the injector timer (voltage) & a Voltmeter to the output the ...
0
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1answer
113 views

Use OP27 as an 'unit-gain buffer'

In OP27's datasheet, p. 14, it shows a graph when use OP27 as an 'unity-gain buffer', and give it a step input (I think it's a positive step). But it doesn't explain more about the waveform on the ...