Patent ID: 8867246

Claim:
A communication device, comprising: a CMOS inverter configured to transfer a signal, the signal being transferred and received between an electronic device and a control part able to communicate with the electronic device whose electric power supply is a rechargeable battery, said CMOS inverter including a P channel MOS transistor and a N channel MOS transistor, said P channel MOS transistor and said N channel MOS transistor having a common gate to which the signal from the electronic device is input, and a common drain for outputting an inverse signal of the signal from the electronic device; and a regulator configured to generate a regulated voltage, the regulated voltage being formed by decreasing an electric power supply voltage of the electronic device, wherein the regulator includes a depletion type NMOS transistor where a drain is connected to a high electric potential side of the electric power supply voltage and a gate and a source are mutually connected, and a capacitive element having an electrode connected to the source side of the depletion type NMOS transistor and another electrode connected to a low electric potential side of the electric power supply voltage, wherein a voltage of the capacitive element is supplied between sources of the P channel MOS transistor and the N channel MOS transistor of the CMOS inverter.