DIFFERENTIAL OPERATIONAL AMPLIFIER WITH LOW SUPPLY VOLTAGE Russian patent published in 2011 - IPC H03F3/34 H03F3/45 

FIELD: radio engineering.

SUBSTANCE: differential operational amplifier comprises the first (1) and the second (2) input transistors (T), combined emitters of which via the first (3) current-stabilising dipole are connected to the bus of the first (4) supply source (SS), a collector of the first (1) input T via the first (5) dipole of collector load (CL) is connected to the bus of the second (6) SS, the collector of the second (2) input T via the second (7) CL is connected with the bus of the second (6) SS and is connected with the input of the buffer amplifier (8). The circuit comprises the third (9) and fourth (10) input T, and also an additional T (11), the base of third (9) input T is connected with the base of the first (1) input T, emitter of the third (9) input T is connected with the emitter of the first (1) input T, the collector of the third (9) input T is connected to the base of the auxiliary T (11) and collector of the first (1) input T, the base of the fourth (10) input T is connected to the base of the second (2) input T, the emitter of the fourth (10) input T is connected to the emitter of the second (2) input T, the collector of the fourth (10) input T is connected to the bus of the second (6) SS, the collector of the additional T (11) is connected with the input of the buffer amplifier (8), and the emitter of the additional T (11) is connected to the bus of the first (4) SS via the circuit of potentials matching (12).

EFFECT: increased limit values of amplification ratio by differential amplifier voltage at low-voltage supply.

3 cl, 6 dwg