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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63 views

Understanding how a tristate buffer works (74LS241)

I'm trying to understand how the 74LS241 works. From what I read, if two input are high on a buffer, then the output will be high. For some reason, this isn't working on my circuit. So here is ...
2
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1answer
93 views

How to increase fanout of CMOS buffer

I'm new to online forum. I want to interface 74HC541(Buffer) to 74HC574(D-f/f). The thing is 100's of D-f/f parallel interface as shown in figure(Fig.1). Input and load capacitance limits it to 10 to ...
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2answers
54 views

lm358 arranged as a 5 volt Buffer

simulate this circuit – Schematic created using CircuitLab I am trying to connect my lm358 so that it acts like a buffer. I am connecting: VCC to + 5 volts Ground to Ground Non-inverting ...
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2answers
26 views

Input buffer on a differential ADC

I am working on a AK5578 ADC, and the datasheet gives the following example for an input buffer : I can't figure out the usefulness of the 10 ohm resistor on output of both opamps. Are they for ...
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3answers
1k views

What is the purpose a buffer gate?

As I understand a buffer gate is the opposite of a NOT gate and does not change the input: However I sometimes see buffer gate ICs used in circuits and to an inexperienced eye they seem to do ...
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2answers
80 views

Difference between buffer and mailbox

Peripherals in Micro-controllers usually provide a way for us to send and receive data from it. Usually this are memory mapped registers. I have come across few terminologies. The most often used one ...
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1answer
48 views

How to get current to the load with a buffer Op Amp

I am reading about voltage buffer Op Amp configurations and it seems like there is no current through the circuit, specifically the load. So why would you want to get a specific voltage to the load if ...
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3answers
80 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 ...
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1answer
107 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
583 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 ...
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votes
1answer
75 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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1answer
46 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
130 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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2answers
114 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 ...
1
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0answers
36 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. AD8475 ...
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1answer
37 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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3answers
80 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
279 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
152 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
114 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: http://www.scotthelmke.com/Mint-box-...
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2answers
220 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
74 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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1answer
89 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 ...
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2answers
91 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
215 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 ...
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2answers
198 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
99 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
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1answer
27 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
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1answer
85 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 zero ...
2
votes
1answer
142 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
144 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
114 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 3-...
5
votes
1answer
139 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
463 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
142 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
186 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
126 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
votes
2answers
130 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
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1answer
170 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
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2answers
121 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
96 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
195 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
153 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
105 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
123 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
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2answers
478 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
912 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
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1answer
636 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
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1answer
122 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 FPGA(...