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

FIELD: electricity.

SUBSTANCE: differential amplifier includes input differential cascade (1) with the first (2) and the second (3) current outputs, the emitter circuit of which is connected to the first (4) bus of power sources, the first (5) and the second (6) transistors of active load, the emitters of which are connected to the second (7) bus of power sources; collector of the first (5) transistor of active load is connected to base of the same transistor, as well as base of the second (6) active load transistor and connected to the second (2) current output of input differential cascade (1); collector of the second (6) active load transistor is connected to the second (3) current output of input differential cascade (1) and bases of the first (8) and the second (9) output transistors the emitters of which are connected to the second (7) bus of power sources; the first current-stabilising bipole (10) connected through the first output to collector of the first (8) output transistor, and through the second output to the first (4) bus of power source; the first (11) current mirror the common emitter output of which is connected to the second (7) bus of power sources; output is connected to the input of the second (12) current mirror; at that, output of the second (12) current mirror is connected to collector of the second (9) output transistor and output of device (13), and common emitter output of this current mirror is connected to the first (4) bus of power sources. To the diagram there introduced is additional transistor (14) the collector of which is connected to input of the first (11) current mirror, emitter is connected to the first output of the first (10) current-stabilising bipole, and base is connected to setup circuit of static mode (15).

EFFECT: U_offset is decreased.

5 cl, 9 dwg