Abstract: A front-end module includes a duplexer, a band pass filter, and a terminating circuit element. A first signal path connects an output terminal of a power amplifier and a transmit node of the duplexer. The band pass filter is disposed on a second signal path between a branch point and a ground. The second signal path branches off from the first signal path at the branch point. The band pass filter has frequency characteristics in which, among frequency components of a transmit signal output from the power amplifier, frequency components that overlap at least part of the pass band of a receive filter of the duplexer are allowed to pass through the band pass filter. The terminating circuit element is disposed on the second signal path between the band pass filter and the ground. The terminating circuit element attenuates a transmit signal passing through the band pass filter.

Abstract: A front-end module includes a duplexer, a band pass filter, and a terminating circuit element. A first signal path connects an output terminal of a power amplifier and a transmit node of the duplexer. The band pass filter is disposed on a second signal path between a branch point and a ground. The second signal path branches off from the first signal path at the branch point. The band pass filter has frequency characteristics in which, among frequency components of a transmit signal output from the power amplifier, frequency components that overlap at least part of the pass band of a receive filter of the duplexer are allowed to pass through the band pass filter. The terminating circuit element is disposed on the second signal path between the band pass filter and the ground. The terminating circuit element attenuates a transmit signal passing through the band pass filter.

Abstract: A differential amplifier receives a reference voltage and a divided voltage dividing an output voltage, and outputs a control voltage in accordance with the difference between the reference voltage and the divided voltage. The control voltage output from the differential amplifier is supplied to an output amplifier. The output amplifier generates a stabilized output voltage from a high-potential-side power supply voltage in accordance with the control voltage. A P-type MOS transistor is connected to a node of the output voltage, and the MOS transistor carries a current from the node of the output voltage. A current control circuit controls a gate of the P-type MOS transistor so that the current flowing through the P-type MOS transistor becomes a constant value.

Abstract: A resistance adjusting circuit including a semiconductor integrated circuit includes a reference voltage generating circuit which generates a reference voltage corresponding to a resistance of an external resistor element connected to the semiconductor integrated circuit, a comparison voltage generating circuit which comprises a replica resistor circuit whose resistance is adjusted according to a resistance control signal and generates a comparison voltage corresponding to a resistance of the replica resistor circuit, a main body resistor circuit which has substantially the same configuration as that of the replica resistor circuit and whose resistance is adjusted according to the resistance control signal, and a control signal generating circuit which receives the reference and comparison voltages and converts the voltages to frequency signals corresponding to the voltages, integrates the frequency signals to produce integration data of the frequency signals, and generates the resistance control signal based

Abstract: A resistance adjusting circuit including a semiconductor integrated circuit includes a reference voltage generating circuit which generates a reference voltage corresponding to a resistance of an external resistor element connected to the semiconductor integrated circuit, a comparison voltage generating circuit which comprises a replica resistor circuit whose resistance is adjusted according to a resistance control signal and generates a comparison voltage corresponding to a resistance of the replica resistor circuit, a main body resistor circuit which has substantially the same configuration as that of the replica resistor circuit and whose resistance is adjusted according to the resistance control signal, and a control signal generating circuit which receives the reference and comparison voltages and converts the voltages to frequency signals corresponding to the voltages, integrates the frequency signals to produce integration data of the frequency signals, and generates the resistance control signal based

Abstract: A differential amplifier receives a reference voltage and a divided voltage dividing an output voltage, and outputs a control voltage in accordance with the difference between the reference voltage and the divided voltage. The control voltage output from the differential amplifier is supplied to an output amplifier. The output amplifier generates a stabilized output voltage from a high-potential-side power supply voltage in accordance with the control voltage. A P-type MOS transistor is connected to a node of the output voltage, and the MOS transistor carries a current from the node of the output voltage. A current control circuit controls a gate of the P-type MOS transistor so that the current flowing through the P-type MOS transistor becomes a constant value.

Abstract: According to the present invention, there is provided a semiconductor device having: a switching element serially connected to a resistive element to be measured; a plurality of transistors respectively connected in parallel to a series circuit consisting of the resistive element to be measured and the switching element, which will respectively take desired resistance values when turned on; and a measurement section which measures a resistance value of a parasitic resistance which occurs so as to be coupled to the resistive element to be measured by turning off the switching element and then controlling switching operations of the plurality of transistors to change the resistance values of resistors formed by the plurality of transistors, and subsequently measures a resistance value of the resistive element to be measured based on a resistance value of the parasitic resistance by turning on the switching element while turning off the plurality of transistors.