A monolithic operational amplifier is disclosed suitable for high voltage operation including an input transistor protection capability under large signal swing and a negative short circuit limit function. Another feature includes an internal current regulator and a protection circuit for circuit turn on.

A fast slewing operational amplifier having as an output stage an inverting integrator and as an input stage a differential amplifier. The output current of the differential amplifier varies in accordance with the differential input voltage to cause the integrator stage to slew in an exponential manner. The differential amplifier includes two pairs of complementary transistors with their emitters cross-coupled.

A low input current, high response rate solid state operational amplifier is provided by coupling low input current emitter follower circuits to the inputs of a differential amplifier circuit which has been gain stabilized by the use of multiple collector transistors and current feedback.

In an integrated operational amplifier, a reference transistor has a base electrode directly connected to the base electrode of a feedback transistor, a collector electrode directly connected to its own base electrode and an emitter electrode directly connected to a source of reference voltage. The collector-emitter path of the feedback transistor is connected in series with an ohmic resistor to the emitter electrodes of both transistors of a difference amplifier.

Operational video circuit modules in microelectronic form connectable to other operational video circuit modules performing the same or a different function. The standards concern the admissible peak-to-peak amplitude of the video signals (1 volt), the direct current component amplitude 0.5 volt, the stray direct current output (5 millivolts) for a zero direct current input. Means are provided for cancelling the stray direct current output in each module by means of a temperature-compensated cur...

An operational amplifier driver circuit for supplying an undistorted ac signal to a resistive load connected across a balanced pair of twisted transmission lines where the balanced lines have common mode noise signals thereon due to the presence of substantial noise of an external, uncontrolled nature. The driver circuit includes a pair of operational amplifiers interconnected to utilize the common mode noise signals in feedback paths thereof whereby the operational amplifiers are able to operat...

A sample and hold circuit is disclosed which employs a matched pair of operational amplifiers as a decoupling circuit to isolate the output of the sample and hold circuit from the sampling capacitor. Prior art decoupling circuits employ a simple isolation amplifier which has a tendency to charge the sampling capacitor with the isolation amplifier input bias and leakage currents. The disclosed decoupling circuit employs one of a pair of matched operational amplifiers as a compensation circuit to ...

A sample and hold circuit is disclosed which employs a matched pair of operational amplifiers as a decoupling circuit to isolate the output of the sample and hold circuit from the sampling capacitor. Prior art decoupling circuits employ a simple isolation amplifier which has a tendency to charge the sampling capacitor with the isolation amplifier input bias and leakage currents. The disclosed decoupling circuit employs one of a pair of matched operational amplifiers as a self-compensating isolat...

A pair of field effect transistors are series connected with one acting as a current source to bias the second which acts as a source follower. A photodiode, connected between the source follower gate and source, operates in response to light to change the current in the source follower. The photodiode is biased by the collector of a bipolar transistor that is connected as a negative feedback amplifier operating around the source follower stage. This configuration maintains close to zero bias on...

A differential operational amplifier comprises a differential input circuit that provides a differential output signal to a plurality of independent output circuits. The gains of the differential input circuit and one output circuit are set by a fixed bias source. A variable bias source controlled by an external signal determines the gain of each other output circuit so that various attenuation characteristics are obtained in the other output circuits without affecting the operating conditions o...