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.
5
votes
5answers
162 views
Stability problem in unity-gain opAmp
As a part of a controlled power supply for hardware-in-loop testing for a student driven project, I had to develop a current buffer (voltage follower) which could source up to 1 A.
I had the (bad) ...
2
votes
1answer
72 views
How do I buffer a high Frequency clock on a Spartan 6?
I am trying to create a high speed clock on my Spartan 6 Atlys Board. The onboard clonck is 100MHz. I am trying to use an on chip PLL to get a faster clock. I am using a the clocking wizard IP to ...
3
votes
1answer
82 views
Strange behavior from variable-gain amplifier
Sorry, this might not go anywhere. My first SE question, though, on any site.
I've built at least three distinct audio amplifiers with the TDA7056B, which is a really great amp. It takes a voltage ...
1
vote
1answer
169 views
Design 8X1 MUX with enable using three state buffers and any logic blocks you need
I have no idea where to start.
I know how to create a MUX but how can I create it using three state buffers ?
0
votes
2answers
97 views
Darlington Emitter-follower used as a buffer
I have a circuit with a Darlington emitter follower used as a buffer between a common emitter amplifier and a low resistance load (speaker). i wanted to know if this arrangement could alone (with the ...
1
vote
1answer
67 views
Non-inverting version of EL7232? (High-frequencey 3-state DIP driver/buffer)
I'm driving a large number of parallel UART inputs from a single UART output, at 2 Mbit. Currently, I'm driving with a Atmega32u4 using a 70 Ohm current limiting resistor (which in theory would allow ...
1
vote
2answers
157 views
Oscillation won't pass voltage buffer
This is the full schematic of the circuit
Full size: http://img443.imageshack.us/img443/9292/fulltheremin.png
It didn't work on the first try.
A theremin is an electric instrument which emit a ...
1
vote
2answers
198 views
Can I use an RC4558 as a voltage follower (buffer) for line level audio?
I've spent hours reading on buffers, non-inverting amplifiers and inverting amplifiers. I get the concept (though I don't understand all the formulas) and I can't make a simple voltage-follower out of ...
1
vote
1answer
201 views
Why does the use of Tristate-Buffer prevent exceeding the fan-out?
Why does the use of a Tristate-Buffer in digital-circuits prevent exceeding the fan-out of logic gates? The number of Logic Gates-inputs, that are connected to a single output is the same, as using no ...
3
votes
1answer
165 views
Long Chains of Shift Registers
I want to set up an LED display, and I'm looking at using a bunch of 16-bit LED driver chips (like TI TLC5927) to run a 16x16 LED matrix. Then I'd like to maybe put a few of these 16x16 displays ...
2
votes
2answers
119 views
What are the typical uses for a non-inverting quad buffer IC?
Do excuse my lack of knowledge on the subject, but on the Opendous JTAG schematic there are two 74LCX125 IC's. The datasheet refers to them as Low Voltage Quad Buffers, but I don't fully understand ...
0
votes
0answers
362 views
Arduino Uno Serial Buffer Overflow
I ran into some problems using the SoftwareSerial-Library of my Arduino Uno R3:
Sending and receiving signals (...
0
votes
1answer
153 views
Pull-down resistor with ADM485
I have ADM485 already mounted and an output of some device, buffered by CD4050BM. For the circuit to be safe for the RS485 bus, the ADM transiver initially should either be in Z-state or read-state. ...
1
vote
1answer
132 views
Circuit for controlled buffer
I designed a circuit that requires buffers with the control gate (not like the ic's that have the control that will make every buffer turn on or off) . I am wondering how this works, and how it can ...
0
votes
1answer
76 views
Problem with octal buffers
I have a bunch of random IC's from electronic goldmine and one of them includes the MM74HCT541 octal 3 state buffer.
So just a simple circuit to test it, I have 4x AA batteries and I am hooking this ...
1
vote
2answers
133 views
Application of buffer chip in serial communication
On a microcontroller board that I am working on, there is a buffer chip between the microcontroller TI msp430 F1611 and USB interface ...
-2
votes
1answer
81 views
COM Buffering MICRO PC to store data and transmit over LAN
I'm lokinkg for a simple piece of hardware for to accomplish data buffering storing and forwarding
1) Has at minimum 3 com port
2) Has 1 or more lan port
3) Support SD storage
3) If possible can ...
0
votes
0answers
171 views
Which op amp for microphone voltage follower?
I have been modifying a 4-channel digital field recorder to use specialist condenser microphones. I have got all the phantom power issues sorted and am able to make recordings. Channels 3 and 4 were ...
2
votes
2answers
170 views
Chosing a pulldown resistor
Setup:
A digital output from a device is connected to an output buffer to drive an optocoupler. If device power is lost the output will go in high-impedance mode.
Problem: I want to make sure that ...
0
votes
2answers
89 views
74LVC1G125 on the arduino wireless shield?
What does the 74LVC1G125 do on the Arduino wireless sheild?
Its just a buffer, but is it really necessary, or is it only necessary if you stack a lot of shields? (ie: collectively increasing input ...
2
votes
2answers
203 views
Is primary memory buffering the only way to access I/O devices and secondary storage?
I'm not sure if this is the right stack exchange site to ask this question so sorry if it's not. If anyone can cite a good book which explains computer architecture in general (not for a specific ...
3
votes
3answers
60 views
Does this buffer's current rating apply to each individual output, or all of them?
I'm thinking of using a SN74ABT244A octal buffer in a circuit that requires the buffer to sink 20mA of current on all eight outputs under worst-case input conditions. In the datasheet, it says that ...
3
votes
1answer
384 views
How to interface with a bus that's powered when the rest of my circuit is off
I'm working on interfacing to a SPI bus that is exhibiting some... bad behavior.
The bus comes from a control box on a toy drumset. The control box is the SPI master, and it can be turned on and off ...
2
votes
1answer
321 views
How does an oscilloscope buffer work?
I am making a simple 1MHz oscilloscope with an embebbed system based on ARM and Android. I have an ADC with a speed of 12MSa/s that takes the samples. I need it to send the samples to a PIC ...
3
votes
3answers
340 views
What is the point of Buffers like this in Programmers?
So this is a schematic for an AVR Programmer seen here:
http://www.sparkfun.com/products/9825
On the bottom you will see a 74AC125 which is a Quad Buffer with Tri-State Outputs. I've seen quite a ...
-1
votes
1answer
164 views
Types of amplifier - what is the difference?
What is the difference between an open loop amplifier and a voltage follower (unity gain buffer)?
2
votes
1answer
89 views
What is causing the input to my buffer to be damaged?
I have recently been having issues where the buffer of the circuit below has been damaged. The output pin (2) does not change with changes to the input pin (1). I sent 2 of these ICs to Fairchild for ...
1
vote
4answers
401 views
Open Collector Tristate Buffer
I'm looking for an IC with the following functional diagram. Basically it's an inverting buffer whose output is open-collector, and that has an enable signal. An equivalent logical circuit would be to ...
1
vote
1answer
703 views
Driving LEDs with 74HC540 or 74HC541?
I have some LEDs (not the high power type) being driven by a 74HC541, one LED per output, with no other load. I've noticed a tendency for people to use the 74HC540 instead (inverting buffer). I've ...
4
votes
2answers
403 views
Capacitor in parallel with resistor on xoscope amplifier schematic
Short version: Why is C3 necessary in this circuit?
Explanation:
The schematic for the input buffer/amplifier circuit for xoscope is made up of subsections that are mostly broken down in the ...
1
vote
2answers
460 views
Recommendations for analog tri-state buffer?
I'm currently working on a project that requires interfacing to a clock and data line at a configurable voltage between 0V-5V with nonstandard logic levels, this voltage is generated elsewhere. To be ...
5
votes
2answers
2k views
FPGA VGA Buffer. How to read and write?
I have an Altera DE2 board and trying to draw sprites. I am having some trouble implementing a screen buffer.
I have a display entity that at a 25 MHZ rate outputs pixels for vga display.
I was ...
1
vote
1answer
230 views
Logic Buffers for CPLDs Outputs (and Inputs?)
Today, I tried to use a ULN2003a darlington array as a buffer for my CPLD's outputs. While it works well, I have a concern. The max. voltage where the Max V is guaranteed to read a low is 0.8V. The ...
1
vote
1answer
155 views
System Generator: Does an fft block need a buffer?
I wonder if is necessary to put a buffer before a FFT block. I want to do a fft, with N = 16 (samples).
Is necessary to design a temporal memory system to save 16 samples before loading into FFT or ...
1
vote
1answer
346 views
System Generator: How to make a buffer implementation
I would like to make a buffer in system generator to use it with a FFT block.
I want to charge 16 values to a FFT block from another system I´ve designed and I need a temporary memory system. Could ...
0
votes
2answers
163 views
Three-state inverting octal buffer
I'm looking for a three-state inverting octal buffer for a replacement part for an old microprocessor lab. The package should be DIP. Ucc should be on pin 20. Chip select should be at pins 1 and 19 ...
3
votes
4answers
412 views
RAM device that plugs into microSD slot?
I have a pair of small battery-operated self-logging 3-axis accelerometer devices that each use a microSD flash device for storage (the GCDC X250-2). Unfortunately, the devices do not buffer microSD ...
3
votes
3answers
2k views
Analog buffer without op-amps
I need to buffer an input signal such that I do not load down the source, which is a 100k resistor. However, I need to buffer at least 6 channels, and for more advanced models I'd like to move to 10 ...
4
votes
3answers
546 views
Help with power-loss protection using capacitor
I designing a circuit will store log data to an SD card. The information will be coming form a parent circuit that this one plugs into. The parent circuit will supply 5V to my daughter card. The ...
5
votes
2answers
922 views
Tiny, cheap audio buffer with mute?
I need to buffer an audio signal (feeding into a variable input impedance), and make it mutable with a digital control. The best thing I can think of is an op-amp (maybe TS971? 3×2 mm SOT23) feeding ...
