An MOS differential amplifier includes a pair of substantially identical branches, each branch having a signal input MOS transistor feeding a separate MOS load transistor. Both branches are supplied current by a single current-source MOS transistor. In order to stabilize the (source-to-drain) bias voltages of the signal input and load transistors against fluctuations caused by semiconductor wafer-to-wafer processing variations, an auxiliary amplifier branch is added (for sensing the bias voltage...

A voltage current transactor including a pair of cross-coupled current generators fed with equal currents from a constant current source. The current generators comprise cascaded bipolar transistor current mirrors in which current magnification is achieved by use of emitter multiplication. The output current is controlled only by the input voltage. Both the input port and output port are isolated in terms of identification (return paths) and while the input port can act on the output port, the r...

A protective circuit for a push-pull power amplifier comprises a load current-detecting resistor connected between the emitters of two transistors jointly constituting the power amplifier, a switch connected between an intermediate point on the load current-detecting resistor and the ground to shut off load current, a load resistance-detecting circuit for detecting the resistance of the load, and a driving circuit for causing the switch to be opened by an output from the load resistance-detectin...

An integrated circuit gain block is obtained by cascading a common collector stage with a complementary common emitter stage. The current density of the common emitter transistor is made sufficiently greater than that of the common collector transistor so that the common emitter V.sub.BE lowest worst case value is higher than the common collector V.sub.BE highest worst case value. This makes the circuit manufacturable in integrated circuit form and permits the circuit to operate from a single po...

The disclosed amplifier includes first and second transistors each having an emitter coupled to a bias source, a base, a first collector and a second collector. A third transistor has a collector connected to another bias source, an emitter connected to the base of the first transistor and to the first collector of the second transistor, and a base for receiving input signals. A fourth transistor has a collector connected to another bias source, an emitter connected to the base of the second tra...

A unity gain amplifier circuit is disclosed which is responsive to an input signal being applied thereto for sourcing current to an output terminal for driving a load. The unity gain amplifier comprises a differential amplifier having first and second differential inputs at which one input thereof the input signal is applied. A current mirroring circuit is provided for producing balance current drive to the differential amplifier and which is coupled to the output thereof. The output of the diff...

In an instrumentation amplifier a differential input is provided, one side of which is connected to an instrument ground that is remote from the amplifier power supply ground. The remote ground can, under some conditions, operate at a potential that is outside the potential span of the amplifier power supply. Such common mode potentials are difficult to cope with when the difference exceeds about 0.6 volt. The circuit employs a pair of transistors biased to equal current densities. The emitters ...

A method and circuit for protecting the output stage of an amplifier from thermal overload. A normally-open, temperature sensitive switch is thermally coupled to the transistors in the output stage and electrically connected across a portion of the feedback resistance element of the amplifier, in one circuit embodiment. Whenever the temperature of the transistors reaches a predetermined threshold level, the switch closes and acts as a low resistance path across that portion of the feedback resis...

A high voltage/high current circuitry includes a push-pull voltage amplification stage connected in tandem with a parallel connected push-pull current amplification stage. For the voltage amplification stage a pair of bipolar operational amplifiers are connected in parallel and operate in a push-pull manner. A pair of switching means are positioned at the output of each of the bipolar operational amplifiers while the outputs of the amplifiers are connected to the inputs through a current gain re...

A power amplifier that divides input power among a plurality of parallel channels through a radial line divider, amplifies the power in each channel with three terminal devices, and combines the amplified power in a radial line combiner to produce an output signal. The radial line divider/combiner includes a radial transmission line having a plurality of sectors symmetrically disposed around the inner radius of a supporting annular substrate. The sectors are connected to respective three termina...