SEMICONDUCTOR INTEGRATED CIRCUIT DEVICE, AND INPUT CIRCUIT

PROBLEM TO BE SOLVED: To provide an input circuit making common use of input terminals for an analog signal and a digital signal, and to provide a semiconductor integrated circuit device mounted with the input circuit. SOLUTION: The input circuit is provided with a reference bias producing circuit (23, 33, 42), a differential amplifier (21), a feedback circuit (32) and a switch (41). The reference bias producing circuit (23, 33, 42) produces a reference bias. The differential amplifier (21) is provided with a non-inverting input terminal (+) receiving an input signal and an inverting input terminal (-) receiving the reference bias. The feedback circuit (32) feeds back an output of the differential amplifier (21) to the inverting input terminal. The switch (41) transfers/blocks a signal fed back by the feedback circuit (32). COPYRIGHT: (C)2008,JPO&INPIT