Semiconductor integrated circuit device and contactless electronic device

摘要

In a semiconductor integrated circuit device and a contactless electronic device, an AC voltage is applied to first and second input terminals. A rectification transistor having a drain (or collector) connected to a second input terminal and gate (or base) and drain (or collector) connected to each other through a first resistor supplies a rectified current between the first and second input terminals. A first voltage detector means produces a control voltage so that the rectified voltage obtained on the source (or emitter) side of the first rectification transistor is equal to a predetermined reference voltage. The first voltage controlled current source can produce current in accordance with the control voltage and supply the current to the first resistor. Such a power supply circuit is mounted in the contactless electronic device.