Abstract: An amplifier circuit includes a first bipolar transistor of which the emitter is connected to the ground, and a bias circuit of the first bipolar transistor. The bias circuit includes a second bipolar transistor constituting a current mirror circuit along with the first bipolar transistor, a first resistor connected to the bases of the first bipolar transistor and the second bipolar transistor, and a third bipolar transistor of which the emitter is connected to the bases of the first bipolar transistor and the second bipolar transistor through the first resistor, and of which the base is connected to the collector of the second bipolar transistor. The first bipolar transistor amplifies a signal input to the base thereof and then outputs the amplified signal from the collector of the first bipolar transistor.

Abstract: An amplifier circuit includes a first bipolar transistor of which the emitter is connected to the ground, and a bias circuit of the first bipolar transistor. The bias circuit includes a second bipolar transistor constituting a current mirror circuit along with the first bipolar transistor, a first resistor connected to the bases of the first bipolar transistor and the second bipolar transistor, and a third bipolar transistor of which the emitter is connected to the bases of the first bipolar transistor and the second bipolar transistor through the first resistor, and of which the base is connected to the collector of the second bipolar transistor. The first bipolar transistor amplifies a signal input to the base thereof and then outputs the amplified signal from the collector of the first bipolar transistor.

Abstract: A semiconductor device (1) comprises a semiconductor substrate (2) on which an integrated circuit (3, 4) is formed, a first ground terminal (7) and a second ground terminal (8) for electrically connecting the integrated circuit (3, 4) to an external ground electrode, and an electrostatic breakdown protection element (5) for electrically connecting the first ground terminal (7) with the second ground terminal (8). The first ground terminal (7) is electrically connected with the semiconductor substrate (2), while the second ground terminal (8) is not electrically connected with the semiconductor substrate (2). A semiconductor device comprises a semiconductor substrate on which an integrated circuit is formed, a first ground terminal and a second ground terminal for electrically connecting the integrated circuit to an external ground electrode, and an electrostatic breakdown protection element for electrically connecting the first ground terminal with the second ground terminal.

Abstract: The present invention relates to a satellite television broadcasting receiver which receives waves from a satellite, selects a broadcasting channel and obtains an FM demodulated video signal by passing a selected signal through the band-pass filter. In this satellite television broadcasting receiver, the video signal superposed with a large energy dispersion signal is inputted to the first clamping circuit at a low level, to eliminate the energy dispersion signal. Thus, a room is provided in the dynamic range of the amplifier at the later stage and the DG and DP of the amplifier at the later stage are maintained at a satisfactory level by the second clamping circuit.

Abstract: A frequency modulator is provided, in which, for instance, a video signal is used as a modulation signal. A differential amplifier is formed by first and second transistors. First and second load resistors are connected between respective collectors of the first and second transistors and a power supply terminal (A). A series circuit of first and second feedback capacitors is inserted between the collector of the first transistor and a base of the second transistor. A series circuit of third and fourth feedback capacitors is inserted between the collector of the second transistor and a base of the first transistor. The respective same electrodes of first and second variable capacitance diodes are connected with each other and the other electrodes thereof are connected respectively to a junction point of the first and second feedback capacitors and to a junction point of the third and fourth feedback capacitors.

Abstract: A first and a second transistors coupled in series by connecting the collector of the first one to the emitter of the second one are connected at the collector of the second transistor through a resistor to a first power source of a voltage as high as about two times the breakdown voltage of these transistors, a third transistor is coupled at the collector to the base of the second transistor and a second power source of the lower voltage than the first power source through a load resistor, and the base of the third transistor is connected to the base of the first transistor; whereby an output voltage of the second transistor is divided into the respective collector-emitter voltages of the first and second transistors, and the output voltage exceeding the breakdown voltage of the transistor is obtainable.