AMPLIFIER CIRCUIT AND CRT MONITOR

摘要

PROBLEM TO BE SOLVED: To prevent a smear from being produced on a CRT display by providing a main amplifier having a feedback control section that suppresses a level fluctuation in an input signal to amplify the input signal and a level shift prevention circuit that receives at least part of a feedback current supplied to the feedback control section as a drawing current to the amplifier circuit. SOLUTION: Even when a feedback current Ib of a main amplifier 16 is increased, a level shift prevention circuit 15 provided with a negative power supply 151 and a resistor Rk receives at least part of the feedback current Ib supplied to a node Q2b by the negative power supply 151 as a drawing current Ia. The feedback control section provided with resistors R1, R2 and a capacitor C1 prevents the amplifier circuit provided with the level shift prevention circuit 15 from being stable in a level shift state to prevent a level of an input signal from being shifted due to lag of feedback control.