3-SERIES SWITCH CIRCUIT

摘要

PROBLEM TO BE SOLVED: To provide a 3-series switch circuit which convert a plurality of functions of a semiconductor integrated circuit with 3-series signal fed to one external terminal and can reduce the number of the external terminal of the semiconductor integrated circuit. ;SOLUTION: A working electric current is fed from electric current sources (Q1-Q9, R1-R3) and electric current sources (Q1-Q9, R1-R3) in a semiconductor integrated circuit (Q1-Q2, R1-R3) in which the working of an external terminal (22) is stopped when first voltage is applied and the working of the external terminal (22) is carried out when second voltage and third voltage is applied, comparative circuit parts (Q1-Q13, R4-R6) in the semiconductor integrated circuit is provided in which first control signal is generated when a voltage of the external terminal (22) is higher than a reference voltage and second control signal is generated when a voltage of the external terminal (22) is lower. In this reason, on/off conversion function of the electric current (Q1-Q9, R1-R3) and first/second control signal conversion signal are carried out with 3-series signal.;COPYRIGHT: (C)2001,JPO