THERMAL-SHUT-DOWN CIRCUIT FOR IC PROTECTION

摘要

a voltage source and resistors (R1,R2) , which are connected in series to the voltage source, distributing the voltage; a constant-current source and a transistor (Q1) to be turned-on according to the electric potential distributed by resistors; a transistor (Q2) operating inversely to the transistor (Q1); a NPN transistor (Q3) operating inversely to the transistor (Q2); a diode and a resistor (D1,R4) for stabilizing the bias of the circuit connected to the exterial terminal; a resistor (R3) controlling the turn-off temperature point of transistor (Q1).