Monolithic integrated voltage regulator

A monolithic integrated voltage regulator for regulating the voltage at which current is supplied from a voltage source (U.sub.E) having positive and negative terminals comprising:

• a differential amplifier having a first input (14) for connection to a reference voltage source (U.sub.o) and having a current mirror circuit (16) coupling its outputs,
• current amplifier means (19) in the form of a current amplifier with inflowing current having its input (20) connected by a conductor (21) to the non-inverting output (27) of said differential amplifier, said current amplifier means having a voltage divider composed of ohmic resistances (24, 25) connected across its output, with the tap thereof connected to the second input (15) of said differential amplifier (11,12), said current amplifier means further comprising:
• an input stage consisting of a first Darlington circuit combination of two NPN transistors (35a,35b);
• an output stage comprising a Lin circuit combination of a PNP transistor (36) and an NPN transistor (37), and
• a second Darlington circuit combination of a first (55) and a second (56)NPN transistors with the emitter of the latter connected through a resistor to said negative terminal of said voltage source and with the common collector connection connected to a voltage that permits active operation of said second Darlington combination (55, 56),
• the emitter of the second NPN transistor (35b) of the first Darlington circuit being connected at least through a resistor (R.sub.3) to the emitter of the second transistor (56) of the second Darlington circuit, the base of the first transistor (55) of said second Darlington combination being connected to said negative terminal by a resistance divider connected between said negative terminal and the output terminal (23) of said voltage regulator, the common collector connection of said first Darlington circuit (35a, 35b) being connected with the base of said PNP transistor (36) of said output stage, the emitter of said NPN transistor (37) of said output stage being connected with said output terminal (23) of said voltage regulator and the emitter of said PNP transistor (36) as well as the collector of said NPN transistor (37) of said output stage being connected with said positive terminal (18) of the voltage source, and
• a circuit stabilizing capacitor (C.sub.1) monolithically integrated into the circuit connected between the said conductor (21) connecting the input of said current amplifier to the noninverting output of said differential amplifier and one of said terminals of said voltage source,
• the stabilized output voltage (U.sub.a) of the voltage regulator (10) being available at said output terminal (23) to which the emitter of said NPN transistor (37) of said output stage is connected.