Renesas Electronics Corporation

Hitachi, Ltd.

Hitachi Microcomputer Engineering, Ltd.

Nobuaki Yoneya

Kazuki Watanabe

Yuichi Ohkubo

Toshihiko Watanabe

Satoru Sekiguchi

A semiconductor integrated circuit device which enables a power-supply voltage terminal and an internal circuit to be isolated from each other in a noncontact operation of a semiconductor integrated circuit device for an IC card, including a first power supply circuit for rectifying and smoothing an AC signal supplied from an antenna, a second power supply circuit which includes a voltage control circuit for controlling a gate terminal voltage of a first MOS transistor, a substrate potential control circuit for forming a source voltage of the first MOS transistor as a substrate voltage, and a second MOS transistor which causes the substrate voltage and the gate voltage of the first MOS transistor to be conductive when using the first power supply circuit, and which causes the substrate voltage and the gate voltage to be nonconductive when using power supplied from an external terminal.

Semiconductor integrated circuit device and IC card using the same

The present invention enables a power-supply voltage terminal and an internal circuit to be isolated from each other in a noncontact operation without largely increasing a chip area in a semiconductor integrated circuit device for an IC card. A semiconductor integrated circuit device comprises: a first power supply circuit for rectifying and smoothing an AC signal supplied from an antenna to an antenna terminal, thereby obtaining a DC voltage in a first power-supply line; a second power supply circuit comprising a voltage control circuit for controlling gate terminal voltage of a first MOS transistor disposed between a power supply terminal to which power is input from the outside and the first power supply line; a substrate potential control circuit for forming source voltage of the first MOS transistor as a substrate voltage; and a second MOS transistor which makes substrate voltage and gate voltage of the first MOS transistor conductive in the case of using the voltage generated by the first power supply circuit as a power supply, and which makes the substrate voltage and the gate voltage nonconductive in the case of using a power supply from an external terminal.

A monolithic semiconductor integrated circuit device includes a differentially operative circuit section, an amplifying element connected to define a current flowing in the differentially operative circuit section and a circuit for adjusting a current flowing in the amplifying element to thereby compensate for variations of electric characteristics from one semiconductor device to another. The current adjusting circuit includes at least one amplifying element and a load resistance for the amplifying element in the current adjusting circuit. The load resistance has a structure suitable for a trimming operation to adjustably determine the resistance value of the load resistance. The amplifying elements are in a current mirror circuit connection with their control electrodes being concerned with each other so that the electric current flowing in the current path between the current receiving and delivering electrodes of the amplifying element connected to define the current flowing in the differentially operative circuit section is controlled by the adjustably determined resistance of the load resistance.

Growing community of inventors

Takasaki, Japan

Nobuaki Yoneya