Abstract: A programmable trigger coupling circuit and trigger circuit for selecting DC and AC coupling modes in addition to a few other coupling modes without using a DC blocking capacitor in series with the signal path. A short high frequency signal path, low pass filter network and a subtraction circuit are used for obtaining the basic trigger coupling modes. Additional circuits may be used for expanded coupling modes and functions.

Abstract: The cascomp amplifier is modified to provide a dynamic biasing circuit which varies the bias point of the cascomp amplifier in proportion to the change in the true bias point of the main channel pair to allow full thermal V.sub.be error correction for overdrive conditions and for common-mode signals. A buffer amplifier senses the average voltage of the main channel input transistor emitters and generates a voltage proportional to this average which is added to the biasing network for the cascomp amplifier common-base amplifier transistors.

Abstract: A trigger circuit including arm and trigger comparators which are responsive to the push-pull output from a differential amplifier but insensitive to its common mode component. A controllable hysteresis insertion circuit is also included in the circuit for noise rejection and sensitivity control purposes.

Abstract: A current-limiting circuit for a differential amplifier includes a voltage generator which is switched in parallel with a signal-current-generating impedance connected between the emitters of the differential amplifier transistors whenever an input signal exceeds the voltage of the voltage generator. A practical embodiment for limiting the current in either direction for opposite-polarity input signals includes a pair of voltage generators cross-coupled from a respective differential amplifier transistor base to the opposite transistor emitter via transistor switches.

Abstract: The cascode feed forward amplifier is modified to correct alpha-induced error. A pair of resistors are serially disposed between the bases of a pair of common-base amplifiers to generate an error voltage proportional to the input signal. The error voltage is applied to the correction amplifier to provide an appropriate correction current.