Buffer Digital Circuits | Electronic Project Circuits

Posts Tagged ‘buffer digital circuits’

Buffer Opamps by CA3140

The buffer electronic with IC Opamps by CA3140 (More circuits use CA3140) or LF353 or TL072.
If output impedance of a point is a high value then connecting another circuit at that point will load it resulting in malfunction or error. Buffers are used as interface between circuits. Low impedance of an output means it can source sink lot of current, when you need 2 opamps use LF353 (More circuits use LF353)or TL072 which are dual opamps. A non-inv FET input is the best buffer, for inverting buffer use high R values Using very high R values like 2.2M or higher requires a glass epoxy PCB and guard rings around pin 2, 3 to prevent leakage currents on the PCB reaching the PINs. Also moisture and dust has to be prevented by using RTV coating or Varnish. Use 78L05 79L05 for the dual supply required by this circuit.

Read more source:http://schematics.blogspot.com/2004/10/buffer-opamps.html

Be the first to comment - What do you think? Posted by admin - May 13, 2008 at 6:05 pm

Categories: Basic electronics Tags: buffer digital circuits, Buffer opamp, CA3140, TL072

PC serial port buffer

This is a simple serial port buffer circuit I designed for a friend to speed up his SLIP connection in campus computer network “TRINET” of Helsinki University of Technology. The problem in the network was that the RS232 commections from rooms to terminal server were long and made of bad quality wiring.

The circuit is a simple buffer which adds more driving capacity to PC serial port for the signal to go succesfully from PC computer to terminal server (other direction had no problems). The computer is connected to connector CON1 and the buffered output is available ar CON2. With this circuit the speed of RS232 connection to termial server could be succesfully raised for 9600 bps to 38400 bps.

The circuit is basically a two transistor buffer consistong of transistors Q1 and Q2 which can drive up to 1A current pulses, but the maximum putput current of the circuit is limited by resistor R2. Value R2 was experimentally selected by testing resistor values in range of 22 ohm to 270 ohm and value 140 ohm gave best results (it provides quite good impedance matching to cable used). It is a good idea to use at least 1W resistor in place of R2 to make sure that it does not overheat in output short circuit situation (RS232 devices must withstand that to meet the standard). [...]

Read More Source: http://www.tkk.fi/Misc/Electronics/circuits/rsbuffer.html

Be the first to comment - What do you think? Posted by admin - October 7, 2007 at 8:44 am

Categories: Circuit com, Microcontroller Tags: buffer digital circuits, Circuit com, rs232 interface

Output buffer by IC 4050

circuit output buffer by IC 4050
If you want the circuit Output buffer for the circuit digital. I begs for to advise IC 4050 (Hex buffers with high-to-low level shifter inputs) because very be IC that be usable easily. use link up digital circuit TTL and CMOS well.