Abstract: A method of inspecting an integrated circuit comprises the steps of supplying an alternating signal to a plurality of different circuits in the integrated circuit, and measuring a signal corresponding to the alternating signal, which is output from each of the circuits.

Abstract: There is provided a double balance type switching circuit including a switching control signal generator; a first differential amplifier formed of first and second transistors; a second differential amplifier connected between the collector of the first transistor and a power supply terminal and formed of third and fourth transistors whose bases are respectively connected to the first and second output terminals of the switching control signal generator; and a third differential amplifier connected between the collector of the second transistor and the power supply terminal and formed of fifth and sixth transistors whose bases are respectively connected to the first and second output terminals of the switching control signal generator.

Abstract: A DC level clamping circuit comprising a differential amplifier circuit constituted by a pair of transistors, a signal source, a first capacitor connected between the signal source and a first input terminal of the amplifier circuit, a second capacitor connected between the ground and a second input terminal of the amplifier circuit and having substantially the same capacity as the first capacitor, a pulse generator, a DC power source and first and second switching elements. The first switching element is connected between the DC power source and the first input terminal of the amplifier circuit, and the second switching element between the DC power source and the second input terminal of the amplifier circuit. These switching elements are controlled by the pulses from the pulse generator in a similar manner.

Abstract: An oscillator comprising an oscillation circuit including an oscillation transistor whose emitter is connected to the ground with respect to a D.C. signal; a detection circuit for detecting D.C. power source current supplied to said oscillation transistor; and a control circuit for controlling a D.C. bias voltage impressed on said oscillation transistor according to an output signal from the detection circuit, wherein the oscillation circuit, detection circuit and control circuit jointly constitute a negative feedback loop for sending direct current back to the source.

Abstract: A Hartley oscillator includes a basic Hartley oscillation circuit having a semiconductor active element, a tank circuit coupled to the active element and having a grounded end, a coupling capacitor connected between the other end of the tank circuit and a control electrode of the active element. A constant direct current source for supplying a constant direct current to an electric current supply terminal of the active element is further provided. A feedback circuit is coupled to the active element and the output of the constant direct current source and adapted to cause a variation of a direct current potential on the current supply terminal of the active element to be fed back to the control electrode of the active element, and a capacitor having a grounded end and the other end connected to the output of the constant current source is further provided in the Hartley oscillator.