Abstract: Disclosed is a laser light transceiver which is configured so as to include a polarization changing unit 2 for outputting a laser light beam outputted from a transmission light source 1 toward a direction corresponding to the polarization of the laser light beam while changing the polarization of the laser light beam with respect to time. As a result, the laser light transceiver can transmit a laser light beam, whose power is not decreased, in two eye directions without mechanically scanning with the laser light beam.

Abstract: Disclosed is a laser light transceiver which is configured so as to include a polarization changing unit 2 for outputting a laser light beam outputted from a transmission light source 1 toward a direction corresponding to the polarization of the laser light beam while changing the polarization of the laser light beam with respect to time. As a result, the laser light transceiver can transmit a laser light beam, whose power is not decreased, in two eye directions without mechanically scanning with the laser light beam.

Abstract: A semiconductor integrated circuit that is efficiently reduced in a noise level is offered. P-channel type MOS transistors M1 and M2 serving as differential input transistors have a thin gate oxide film in order to reduce the noise level. A protection circuit to protect the P-channel type MOS transistors M1 and M2 from overvoltage is formed including P-channel type MOS transistors M3 and M4. The P-channel type MOS transistor M3 is a first protection transistor to protect the P-channel type MOS transistor M1 from overvoltage, and is connected to a drain of the P-channel type MOS transistor M1. The P-channel type MOS transistor M4 is a second protection transistor to protect the P-channel type MOS transistor M2 from overvoltage, and is connected to a drain of the P-channel type MOS transistor M2.

Abstract: A semiconductor integrated circuit that is efficiently reduced in a noise level is offered. P-channel type MOS transistors M1 and M2 serving as differential input transistors have a thin gate oxide film in order to reduce the noise level. A protection circuit to protect the P-channel type MOS transistors M1 and M2 from overvoltage is formed including P-channel type MOS transistors M3 and M4. The P-channel type MOS transistor M3 is a first protection transistor to protect the P-channel type MOS transistor M1 from overvoltage, and is connected to a drain of the P-channel type MOS transistor M1. The P-channel type MOS transistor M4 is a second protection transistor to protect the P-channel type MOS transistor M2 from overvoltage, and is connected to a drain of the P-channel type MOS transistor M2.

Abstract: Deterioration in characteristics of a MOS transistor due to bias instability caused in a stand-by mode is suppressed to prevent deterioration in circuit characteristics. An operational amplifier circuit according to this invention includes MOS transistors for connection that are connected between back gates of differential MOS transistors and their sources and a MOS transistor for biasing that is connected between a power supply potential and the back gates. One of the MOS transistors for connection is a P-channel type MOS transistor having a gate to which a stand-by signal STB is applied. Another of the MOS transistors for connection is an N-channel type MOS transistor having a gate to which the reverse stand-by signal STBB is applied. And the MOS transistor for biasing is a P-channel type MOS transistor having a gate to which the reverse stand-by signal STBB is applied.

Abstract: Deterioration in characteristics of a MOS transistor due to bias instability caused in a stand-by mode is suppressed to prevent deterioration in circuit characteristics. An operational amplifier circuit according to this invention includes MOS transistors for connection that are connected between back gates of differential MOS transistors and their sources and a MOS transistor for biasing that is connected between a power supply potential and the back gates. One of the MOS transistors for connection is a P-channel type MOS transistor having a gate to which a stand-by signal STB is applied. Another of the MOS transistors for connection is an N-channel type MOS transistor having a gate to which the reverse stand-by signal STBB is applied. And the MOS transistor for biasing is a P-channel type MOS transistor having a gate to which the reverse stand-by signal STBB is applied.