Low voltage differential amplifier with limited output voltage - has reference voltage comparator for regulation of currents drawn by current mirror transistors in collector circuits

摘要

Emitter-coupled transistors (T1,T2) driven from input terminals (E1,E2) draw upon a current-mirror combination (T6,T7) whose bases are linked to that of a current source (T8) setting the max. current (IM) of a regulator (R) driven from the output terminals (A1,A2). A comparator (T3-T5) sets the equal currents (IR) of a controllable current mirror (T10,T11) by means of a regulation current (IS) through a diode-connected transistor (T9) in cascode with the reference transistor (T5). USE/ADVANTAGE - Esp. as integrator or preamplifier, circuit requires only 1 to 1.2 V supply and is usable in appts. powered from single Ni-Cd battery.