Abstract: An acoustic drive circuit for driving a headphone for converting variation of magnetic force, occurring to a voice coil, in sound, and outputting the sound, includes a power amplifier for amplifying a signal at a frequency within the speech band, and outputting the signal after amplification, at a voltage with a given bias voltage superposed thereon, to one end of the voice coil of the headphone, and a pulse generation circuit for generating a pulse signal at a frequency higher than those in the speech band, having an average voltage equivalent to the bias voltage, and for outputting the pulse signal to the other end of the voice coil. The pulse generation circuit generates rectangular waves at a frequency higher than those in the speech band, having a duty ratio such that the average voltage is equivalent to the bias voltage.

Abstract: A first inverter includes a plurality of first gate elements having first gate electrodes which extend in a first direction. A second inverter includes a plurality of second gate elements having second gate electrodes which extend in the first direction. A gate length of the first gate electrodes is the same as a gate length of the second gate electrodes, and a gate width of the first gate electrodes which is defined by a first active region, is the same as a gate width of the second gate electrodes which is defined by a second active region.

Abstract: This invention may provide a headphone driving circuit needless of coupling condenser even if the power supply supplies a single output voltage. The headphone driving circuit comprises (1) a first amplifier to amplify a first composite signal generated by subtracting a second channel audio signal from a first channel audio signal, then driving one end of a first voice coil of a stereo-headphone, (2) a second amplifier to amplify a second composite signal generated by subtracting the first channel audio signal from the second channel audio signal, then driving one end of a second voice coil of the stereo-headphone, (3) a third amplifier to amplify a third composite signal generated by adding the first channel audio signal and the second channel audio signal for driving the other end of the first and the second voice coil of the stereo-headphone.

Abstract: A semiconductor IC (Integrated Circuit) has blocks implemented as a standard cell each. Wirings are arranged in a wiring region for wiring the connections of circuit devices of a standard cell, which constitute utility circuit. A first and a second electrode each are formed in a particular polycrystalline silicon layer in the wiring region different from a layer assigned to the wirings. Either of the two electrodes is connected to a power supply while the other is connected to ground, forming a capacitance between the overlapping portions thereof.

Abstract: An acoustic drive circuit for driving a headphone for converting variation of magnetic force, occurring to a voice coil, in sound, and outputting the sound, comprises a power amplifier for amplifying a signal at a frequency within the speech band, and outputting the signal after amplification, at a voltage with a given bias voltage superposed thereon, to one end of the voice coil of the headphone, and a pulse generation circuit for generating a pulse signal at a frequency higher than those in the speech band, having an average voltage equivalent to the bias voltage, and for outputting the pulse signal to the other end of the voice coil. The pulse generation circuit generates rectangular waves at a frequency higher than those in the speech band, having a duty ratio such that the average voltage is equivalent to the bias voltage.

Abstract: A semiconductor IC (Integrated Circuit) has blocks implemented as a standard cell each. Wirings are arranged in a wiring region for wiring the connections of circuit devices of a standard cell, which constitute utility circuit. A first and a second electrode each are formed in a particular polycrystalline silicon layer in the wiring region different from a layer assigned to the wirings. Either of the two electrodes is connected to a power supply while the other is connected to ground, forming a capacitance between the overlapping portions thereof.

Abstract: A first inverter includes a plurality of first gate elements having first gate electrodes which extend in a first direction. A second inverter includes a plurality of second gate elements having second gate electrodes which extend in the first direction. A gate length of the first gate electrodes is the same as a gate length of the second gate electrodes, and a gate width of the first gate electrodes which is defined by a first active region, is the same as a gate width of the second gate electrodes which is defined by a second active region.