Tag «Video Circuit»

Voltage Controlled Variable Gain Video Amplifier

This is a video amplifier circuit featured with controllable variable gain.  The control is done by adjusting the voltage of grid inputs of two FETs, which are configured as programmable voltage divider. This circuit can generate dynamic linear range attenuation up to 100 dB. This circuit still give a linear attenuation even at f=10.7MHz.  You …

LM1201 Video Amplifier with Balanced (Bi-Phase) Output

This is a schematic diagram of video amplifier circuit with bi-phase output.  Bi-phase output provides both positive-going and negative-going signal, and can be used as balanced signaling. The main component of this circuit is LM1201.  In this circuit, the inverted video is obtained at pin 10 because of the 75Ω termination to the power supply …

15 Channels Cascaded MAX455 Video Mux

On this following circuit shown in the schematic diagram, two MAX455s IC chip are cascaded to build a 1 of 15 video Multiplexer. This cascading is done by connecting the output of one MAX455 MUX to one input of  a second MAX455 MUX. The output of the first MUX should be terminated to ground using …

Fast Amplifier Circuit with DC Stabilization

This amplifier circuit combines the LT1010 and a fast discrete stage with an LT1008 based dc stabilizing loop. A differential stage which is single-ends into the LT1010 is formed by Q1 and Q2.  An output of 1 V pk-pk into a typical 75-Ω video load is delivered by the circuit.  With gain = 2, the …

Remote Video System Multiplexer

Combination 8 channel multiplexer and amplifier (IC1) is the heart of the remote multiplexer box in the single coax video system. The MUX baseband video output is coupled by C11 to the coax and the video is decoupled by L1 from dc power arriving on the same line. All circuitry in the multiplexer box is …

High Impedance Low Capacitance Buffer/Amplifier

These are circuits of high impedance low capacitance buffer and high impedance low capacitance  amplifier. First figure is a high impedance low capacitance buffer circuit, it uses the 2N446 JFET that features low input capacitance. The feedback buffer a wide-band unity gain amplifier is made from this 2N446 JFET. Here is the circuit : The …

JFET-Bipolar Cascode Circuit

This is JFET-bipolar cascode circuit. It will provide full video output for the CRT cathode drive. The gain of this circuit is about 90. Here is the circuit : This circuit employs 2N4091 JFET to solve Miller capacitance problems using cascode configuration. It will alow direct drive from the video detector. The video amplifier will …