Abstract: A video amplifier having an on-screen display (OSD) capability uses one channel of an OSD input video signal to generate a blanking signal for blocking output of a video signal. When the blanking signal is asserted, the OSD channels provide the on-screen display. The blanking signal is generated in a high speed mixer circuit including an emitter-coupled differential pair for amplifying the OSD input signal about an operating DC offset voltage and a pull down circuit for providing the blanking signal.

Abstract: A video preamplifier having an on-screen display (OSD) capability uses one channel of an OSD input video signal to generate a blanking signal for blocking output of a video signal. When the blanking signal is asserted, the remainder two channels provide the on-screen display. The blanking signal is generated in a high speed mixer circuit including an emitter-coupled differential pair for amplifying the OSD input signal about an operating DC offset voltage and a pull down circuit for providing the blanking signal.

Abstract: A video preamplifier having an on-screen display (OSD) capability uses one channel of an OSD input video signal to generate a blanking signal for blocking output of a video signal. When the blanking signal is asserted, the remainder two channels provide the on-screen display. The blanking signal is generated in a high speed mixer circuit including an emitter-coupled differential pair for amplifying the OSD input signal about an operating DC offset voltage and a pull down circuit for providing the blanking signal.

Abstract: An RGB video display terminal (VDT) is disclosed and the color cathode ray tube (CRT) driver circuits detailed. The driver circuits include a common video gain control which can be varied over a wide range without changing the DC bias level. Each CRT gun can have its driver gain separately controlled over a vernier range and its DC bias can be separately controlled. The video amplifier is AC coupled to the video input and includes a DC reinsertion circuit which clamps the DC bias at a level related to the composite video level immediately following the sync pulse. Therefore, the DC reinsertion is clamped for each scanning line at the CRT black level. The video amplifier also includes a blanking circuit which turns the CRT guns off during the VDT retrace interval. Thus, the driver circuits can drive the CRT guns in a manner that will simultaneously control their operation for the color display and yet take into account the manufacturing tolerance in individual gun characteristics.

Abstract: A wide bandwidth amplifier is shown along with a muting circuit. The output shift between normal operation and mute is kept very small. The amplifier is useful in video disk and audio signal reproduction.

Abstract: A plurality of differential amplifier stages in cascaded in a directly coupled configuration to provide substantial signal gain. The first few stages are cascode coupled to a plural input differential signal combiner which has a single differential output that feeds a full wave differential peak detector. The peak detector therefore has an output that rises as a log function of the signal input. This signal-related voltage is then fed to a differential dc amplifier which in turn drives a meter that indicates the log of the input signal strength. The amplifier cascade is stabilized by a dc feedback loop.

Abstract: In a radio receiver IF amplifier, a high gain AGC circuit produces a constant signal output regardless of input signal levels in excess of a threshold value. A summing amplifier responds to the AGC voltage and the IF amplifier current to develop a d-c potential directly proportional to the signal input to the amplifier both above and below the AGC threshold. This voltage is useful in the squelch and signal strength meter circuits.

Abstract: In a radio receiver IF amplifier, a high gain AGC circuit produces a constant signal output regardless of input signal levels in excess of a threshold value. A summing amplifier responds to the AGC voltage and the IF amplifier current to develop a d - c potential directly proportional to the signal input to the amplifier both above and below the AGC threshold. This voltage is useful in the squelch and signal strength meter circuits.

Abstract: A high gain integrated circuit amplifier is arranged in the form of a pair of cascaded common emitter stages. A current mirror is employed to track the stage currents. A high gain d-c negative feedback loop is employed to stabilize the amplifier, and each stage employs emitter diode degeneration to control gain as a function of current. Gain control is obtained by sinking current at a single node in one stage.