Abstract: A switch circuit device includes a switch circuitry and a driver circuitry. The switch circuitry switches an electrical connection between first and second terminals between the on-state and the off-state in response to a set of control signals. The driver circuitry is configured to generate the control signals and includes an N-latch circuit and a leakage current suppression circuitry. The N-latch circuit selectively outputs lower one of two input voltages fed thereto as one of the control signals. The leakage current suppression circuitry suppresses the leakage current through the N-latch circuit.

Abstract: An amplifying device comprises a first amplifying unit (91-97) capable of changing its gain in a stepwise manner, a second amplifying unit 99 cascade-connected to the first amplifying unit (91-97), the second amplifying unit being capable of changing its gain in a stepwise manner, and a gain controller 100 controls the gain setting of the first amplifying 91-97 unit and the second amplifying unit 99. The first amplifying unit has a gain variable range necessary to amplifying the input signal to the prescribed desired level. The second amplifying unit has a gain variable range narrower than that of the first amplifying unit. When the gain controller changes the gain setting, the gain controller uses the second amplifying unit preferentially over the first amplifying unit.

Abstract: A switch circuit device includes a switch circuitry and a driver circuitry. The switch circuitry switches an electrical connection between first and second terminals between the on-state and the off-state in response to a set of control signals. The driver circuitry is configured to generate the control signals and includes an N-latch circuit and a leakage current suppression circuitry. The N-latch circuit selectively outputs lower one of two input voltages fed thereto as one of the control signals. The leakage current suppression circuitry suppresses the leakage current through the N-latch circuit.

Abstract: A signal processing device suppresses a DC offset without omission of a low-frequency component of a signal in a receiver in a direct conversion system. The signal processing device includes an input terminal 29, a gain amplifier 31 that amplifies an input signal to generate an output signal, comparators 32 and 33 each of which compares an output signal level with a reference value, a capacitor 37, current source circuits 34 and 35, one of which charges or discharges electric charges stored in the capacitor when the output signal level falls outside a reference range according to results of comparisons by the comparators, a variable current source 36 through which current to be flow is controlled according to a potential at the capacitor, and a load circuit 38 that is connected between the input terminal and the variable current source and supplies a bias to the input terminal, together with the variable current source.

Abstract: An amplifying device comprises a first amplifying unit (91-97) capable of changing its gain in a stepwise manner, a second amplifying unit 99 cascade-connected to the first amplifying unit (91-97), the second amplifying unit being capable of changing its gain in a stepwise manner, and a gain controller 100 controls the gain setting of the first amplifying 91-97 unit and the second amplifying unit 99. The first amplifying unit has a gain variable range necessary to amplifying the input signal to the prescribed desired level. The second amplifying unit has a gain variable range narrower than that of the first amplifying unit. When the gain controller changes the gain setting, the gain controller uses the second amplifying unit preferentially over the first amplifying unit.

Abstract: A signal processing device suppresses a DC offset without omission of a low-frequency component of a signal in a receiver in a direct conversion system. The signal processing device includes an input terminal 29, a gain amplifier 31 that amplifies an input signal to generate an output signal, comparators 32 and 33 each of which compares an output signal level with a reference value, a capacitor 37, current source circuits 34 and 35, one of which charges or discharges electric charges stored in the capacitor when the output signal level falls outside a reference range according to results of comparisons by the comparators, a variable current source 36 through which current to be flow is controlled according to a potential at the capacitor, and a load circuit 38 that is connected between the input terminal and the variable current source and supplies a bias to the input terminal, together with the variable current source.