CONSTANT CURRENT CIRCUIT, CONSTANT VOLTAGE CIRCUIT, AND DIFFERENTIAL AMPLIFICATION CIRCUIT

摘要

PROBLEM TO BE SOLVED: To provide a constant current circuit capable of stably supplying a constant current even in an environmental fluctuation or a dispersion of production, and a constant voltage circuit and differential amplification circuit using it. SOLUTION: This constant current circuit comprises a first field effect transistor Tr1having a source and gate connected to a first reference potential terminal 121; first and second resistors R1and R2having one-side ends connected to the first reference potential terminal 121; second and fourth field effect transistors Tr2and Tr4having sources connected to the first and second resistors R1and R2and gates connected to the drain of the first field effect transistor Tr1; a third resistor R3; and a third field effect transistor Tr3having a drain connected to a second reference potential terminal 120 and a gate connected between the third resistor R3and the second field effect transistor Tr2. COPYRIGHT: (C)2004,JPO