DIFFERENTIAL AMPLIFIER CIRCUIT, CONSTANT-CURRENT CIRCUIT AND DISPLAY DEVICE INCLUDING THE CIRCUITS

摘要

PROBLEM TO BE SOLVED: To normally operate a circuit by compensating an offset voltage, regardless of the deviation of threshold voltages of transistors in a differential amplifier circuit. SOLUTION: Vref is given simultaneously to transistors P1 and P2, and an offset voltage generated by the deviation of the threshold voltages of the transistors P3 and P4 is held by a capacity C1. Thereby, the same voltage output can be obtained, regardless of the deviation of the threshold voltages of transistors P3 and P4 at output operation.