Abstract: A charging pump circuit of discharging electric charge charged during charging period to load during boosting period, and an amplifier and a voltage control resistor element arranged in feedback loop by being configured with the feedback loop of feeding back output voltage such that the output voltage of the charging pump circuit is made to be a predetermined value during boosting period are provided, the voltage control resistor element is controlled by the amplifier, and set to a control resistance value of enabling the charging pump circuit to control during boosting period, and the amplifier controls the voltage control resistor element such that the voltage control resistor element is brought into OFF state during charging period, and a resistance value of the voltage control resistor element is lowered to a control resistance value immediately after shifting from charging period to boosting period.

Abstract: An infrared ray receiving circuit includes a band pass filter including two variable transconductance amplifiers, a detector including a differential switch, and a wave-form shaping circuit including a hysteresis comparator. In the infrared ray receiving circuit, the hysteresis width of the hysteresis comparator can be adjusted, so that generation of hair peaks in the output signal of the hysteresis comparator can be avoided. In addition, the generation of an output signal having a pulse width which is shorter than a prescribed pulse width can be avoided.