Abstract: A differential transimpedance amplifier includes a differential transconductance stage to provide a current to a differential transimpedance stage. The differential transimpedance stage includes two gain stages and provides a voltage. A first feedback element is coupled in parallel with the differential transimpedance stage.

Abstract: A video interface circuit reduces loading losses when a video system component, such as a television receiver, is connected to a transmission line by amplifying the video signal with a high frequency amplifier and providing positive feedback of the amplified signal to the cable.

Abstract: Accuracy of correction of offset drift with temperature and noise are corrected in a high voltage, high current amplifier is improved by thermal isolation and/or temperature regulation of another amplifier having greater gain and connected to a different power supply in a closed loop feedback servo system. A clamping network connected to the higher gain amplifier to avoid hard saturation due to transient feedback signals from a reactive load, especially an inductive load, also prevents hard saturation of the high voltage, high current amplifier. An adjustable feedback circuit connected to the higher gain amplifier allows adjustment to obtain critical damping of a second order system and faster response to achieve proportionality of output current to input voltage with an accuracy of very few parts per million error and with minimum settling time.

Abstract: A video signal distribution system comprises an interface device and video signal input means for receiving TV signals on broadcast channels connected to the interface device. A plurality of video appliances and a plurality of TV sets may be connected to the interface device such that the television sets are arranged to be remote from the plurality of video appliances. A person using the system has a remote control device that may be actuated to emit signals for selecting channels for viewing and to control the video appliances. Each of the television sets includes a repeater arranged to receive the control signals from the remote control device and form corresponding electrical control signals. The interface device receives the electrical control signals corresponding to a selected TV set and directs electrical control signals to a selected one of the plurality of video appliances to provide video signals to the television sets.

Abstract: A preamplifier includes an output stage having a bandwidth which is adjustable by a control signal. The output stage includes an amplifier with an adjustable bandwidth. The amplifier includes a main input for receiving an input current, a main output for providing an output voltage, a resistor connected between the main input and output. A current amplifier with an adjustable gain is connected for receiving the input current. A capacitor is connected between an output of the current amplifier and the main output. An inverting transconductance circuit is connected between the output of the current amplifier and the main output.

Abstract: A cascode amplifier which includes a cascode amplifier stage, an output node (coupled directly or indirectly to the cascade amplifier stage), and positive feedback circuitry coupled between the output node and the cascade amplifier stage (or positive feedforward circuitry coupled between the input node and the cascode amplifier stage) for improved amplifier response to rapidly varying input. Preferably, the amplifier is implemented as an integrated circuit or portion of an integrated circuit, and the feedback or feedforward circuitry is configured to reduce rise times and fall times of the output potential (in response to falling and rising edges of the input) to within acceptable limits, with no more than acceptably small overshoot at both the rising and falling edges of the output potential, and with at least substantially equal overshoot at both the rising and falling edges of the output potential.

Abstract: A cascode amplifier which includes a cascade amplifier stage, an output node (coupled directly or indirectly to the cascode amplifier stage), and positive feedback circuitry coupled between the output node and the cascode amplifier stage (or positive feedforward circuitry coupled between the input node and the cascode amplifier stage) for improved amplifier response to rapidly varying input. Preferably, the amplifier is implemented as an integrated circuit or portion of an integrated circuit, and the feedback or feedforward circuitry is configured to reduce rise times and fall times of the output potential (in response to falling and rising edges of the input) to within acceptable limits, with no more than acceptably small overshoot at both the rising and falling edges of the output potential, and with at least substantially equal overshoot at both the rising and falling edges of the output potential.

Abstract: A plurality of field effect transistors (FET's) (11, 12) are coupled in cascode connection. A drain of the final-stage FET (12) is coupled to a gate of the first-stage FET (11) through a first negative-feedback circuit (13). A drain of the first-stage FET (11) is coupled to the gate of the first-stage FET (11) through a second negative-feedback circuit (14). The first negative-feedback circuit (13) is connected to a first resistor (Rf1) while the second negative-feedback circuit (14) is connected to a second resistor (Rf2).

Abstract: A circuit for amplifying an input signal comprises an operational amplifi a dual operational amplifier, and a buffering operational amplifier all cascaded in the aforementioned order. The first operational amplifier amplifies the input signal with minimum noise degradation, is set up as a non-inverting amplifier stage, and has a local negative feedback loop comprising a resistor and capacitor in parallel. The dual operational amplifier has two amplifying devices. One device forms a second amplifying stage which increases the gain of the pre-amplified input signal and has a local negative feedback loop comprising a resistor. The other device is a third operational amplifier which combines with the buffering operational amplifier to form an amplifying and buffering stage. The third operational amplifier connects in series to the output of the second amplifying stage.

Abstract: Linear high gain (greater than 20 dB) and high power (greater than +20 dbm) devices for RF power amplifiers are achieved using either fully monolithic or hybridized versions of silicon MMIC two-stage cascaded amplifiers. The device features three feedback loops in conjunction with a DC biasing network. Resistor-capacitor feedback circuits utilize only two capacitive elements which are provided as a single three-terminal element having a common lower plate.

Abstract: Broadband control amplifier having a wide control range and comprising a differential amplifier in the negative feedback loop. An auxiliary coupling is provided in the feedback loop having a transfer factor which renders the open loop gain independent of the signal distribution in the differential amplifier. The control amplifier can, for example, be used as an input amplifier in a receiver for optical fibre systems, to compensate for the length and temperature-dependent attenuation of the optical link.

Abstract: A distortion-free amplifier in accordance with the present invention includes an input amplifier, an output amplifier and method, and a cooperative combination of negative and positive feedback loops that remove substantially all distortion and error in the amplified output. Negative feedback loops are provided around the output amplifier and the input/output amplifier combination to provide degenerative error reduction. The negative feedback loop around the output stage provides a portion of the output to a voltage node at which the error component of the output signal is inversely superposed on the inverted signal to be amplified. This highly "visible" (inverse, intra-loop) error component is utilized as positive feedback to provide a regeneratively enhanced error pre-correction of the signal in the input amplifier. The pre-correction can be precisely controlled to effect virtually complete serial cancellation of the to-be-introduced error as the signal is propagated through the amplifier.

Abstract: Two high voltage power supplies having negative outputs with respect to common are combined to provide positive as well as negative output with respect to common. An operational preamplifier is used as an inverter. The combination includes provision for programming by means of a voltage returned to common making the system compatible with Conventional remote control systems.

Abstract: Improved slew recovery in a composite driving amplifier for driving a substantially reactive load including a feedback loop to the operational amplifier from the load for regulating the output of the amplifier, the composite amplifier has a predetermined resistance R1 in the feedback loop and includes a second feedback loop having a predetermined resistance R2. The second feedback loop extends from the output of the operational amplifier to the negative input and is substantially parallel with the first-mentioned feedback loop. To maximize the recovery of the amplifier from a slew condition, the relationship of R1-R2 should be as follows: ##EQU1## wherein: V.sub.o is the output voltage in the amplifier.Slope, is the slope of the load voltage curve during the overload condition, andDelay represents the period of time it takes the overload operational amplifier to respond to a feedback signal at a given overload condition.

Abstract: A single adjustable control is commonly connected with each of a plurality of feedback channels, which are selectively coupled in an amplifier circuit to provide the latter with different basic gains, to adjust the respective basic gains of the amplifier circuit by corresponding fractional or proportional amounts of respective ranges of permissible gain chain for each channel, thereby simultaneously to correct or to calibrate each channel for different amounts of drift of the like.

Abstract: A distortion-free amplifier for electric signals has a high-quality low-power amplifier-section. In addition there is a high-power amplifier-section which delivers the majority of the current to the load. A feedback signal is derived which is a measure of the output current of the high-power section and not the low-power section. The feedback signal is applied to the inputs of both amplifier-sections negatively in an amount such as to remove from the combined output currents in the load any distortion occurring in the contribution from the high-power section.