Abstract: An improved voltage level shifting circuit is provided that employs a reference voltage translation circuit having its input at a fixed reference voltage, to bias the operating point of a substantially similar signal voltage circuit. The reference circuit generates a bias current in response to the reference voltage which is coupled back to buffers in the reference and signal translation circuits. The bias current maintains the operating point of the signal translation circuit close to the switching point determined by the reference voltage.

Abstract: A novel driver circuit and feedback loop is provided that improves the response time of the driver circuit and produces threshold voltages and hysteresis levels which are substantially independent of the supply voltage. The feedback circuit uses a pair of transistors connected in a cascode configuration to provide positive feedback from the output of the driver circuit and to control this feedback by means of the signal at the driver circuit input. By coupling the input voltages to the gate of a cascode transistor, the response time of the driver circuit is improved without disturbing its high input impedance. In addition, by replacing a transistor in the driver circuit input buffer with a current source, the threshold voltage of the driver circuit can be made substantially independent of the supply voltage.

Abstract: A current mirror circuit is modified to supply bias current to the input transistor that varies in accordance with variations in the base-emitter voltages of the input and output transistors, and in accordance with the variations in collector voltage of the output transistor. The bias current variations are controlled by a pair of complementary conductivity type transistors that are closely coupled in manner similar to the coupling of the input and output transistors with associated bias supplies and unity gain amplifier connected to alter bias conditions in accordance with variations in the base-emitter voltage and the collector voltage of the output transistor.

Abstract: A current feedback circuit for controlling the error current in current feedback amplifier includes transistor biasing circuitry which monitors the error current to detect high input signal slew rates and switches on a transistor controlled shunt circuit to divert drive current from the transistors forming the amplifier input, when the error current generated exceeds a threshold value.

Abstract: A current compensation circuit for a comparator includes a pair of switching transistors which supply input bias current to their corresponding comparator input transistors, a pair of current to voltage conversion means which use collector current from the comparator input transistors to turn on and off the appropriate switching transistor when its corresponding comparator input transistor is on, a transistor to generate a negative replica of the input bias current flowing in the comparator input, and a current mirror which is programmed by the replica of the uncompensated input bias current to produce a compensated input bias current to the switching transistors.

Abstract: A logic-controlled circuit superimposes a constant voltage across an actuator or motor load that is driven by a bridge-type amplifier to control the constant velocity operation of such load in response to an applied logic signal that may also disable the bridge-type amplifier.

Abstract: An improved direct-coupled transistor amplifier circuit includes a pair of complementary conductivity type output transistors that are quiescently biased to slightly conductive state to provide low distortion amplification and temperature stabilized operating conditions. A pair of complementary conductivity type input transistors receive bias current having a value that is substantially matched to the change with temperature of base-emitter voltage of an input transistor divided by the value of a resistor connecting the emitter of the input transistor to receive the bias current.

Abstract: A bridge-type linear amplifier includes separate local feedback networks on each half-side channel of the amplifier and an additional feedback network between channels of the amplifier in order to correct for differences in current gains of output transistors and requisite drive currents.

Abstract: An overload protection circuit for a disableable amplifier includes a sensing resistor connected to provide indication of the current supplied to the amplifier and includes logic circuitry for producing a disabling control signal for a selected time interval following detection of the overload condition of the amplifier.

Abstract: An improved linear amplifier circuit includes controlled current sources connected to supply additional current to the output stage during rapid change of applied signal. The current sources are responsive to current levels in the input stages and thus need only conduct low levels of current during quiescent operating conditions. Symmetrical and asymmetrical circuit configurations with respect to reference potential are disclosed.

Abstract: An improved linear amplifier circuit includes current mirror circuits that are cross connected in the collector circuits of input transistors for supplying proportional current to circuit nodes from which signal is derived for controlling the output stages. The states for supplying boost current to the circuit nodes are stabilized in quiescent condition to avoid delays commonly associated with the turning on of a non-conducting stage.

Abstract: An improved direct-coupled amplifier includes a push-pull pair of transistors in an output stage that provides high output current on low quiescent current. Each such output transistor is driven by a push-pull pair of driver transistors that receives the applied signal at proper bias levels provided by forward-biased diodes (or diodes and gain element) to provide high input impedance to low output impedance signal buffering with wide bandwidth at high power levels.

Abstract: An improved gain stage includes a pair of differentially-connected, matched, bipolar transistors and local positive feedback from the output to the collector electrode of one input transistor to provide D.C. balance and substantially enhanced voltage gain.