DIFFERENTIAL AMPLIFIER WITH HIGH COMMON MODE REJECTION Russian patent published in 2008 - IPC H03F3/45 

FIELD: electricity.

SUBSTANCE: invention may be used as analogue signal amplifier within the structures of different functional analogue microchips (for example, operational amplifiers, and comparators). Differential amplifier includes input differential stage (1) with reference current source (2) within common emitting circuit having inputs (3) and (4). Reference current source output 1 (5) and 2 (6) are connected with output transistors 1 (7) and 2 (8) emitters and corresponding current-stabilising impedors 1 (9) and 2 (10). Differential amplifier also includes current mirror (11) with input coupled to output transistor collector (7) and output connected to differential amplifier output (12) and output transistor collector (8), offset voltage source (13) linked with integrated bases of output transistors (7) and (8). Circuit is supplemented with additional input differential stage (14) with additional reference current sources (15) in common emitting circuit. Current output 1 (16) of reference current source is connected to additional current mirror input (17), while its output is linked with additional input differential stage (14) current output 2 (18) and output transistor (7) emitter, additional input differential stage (14) inputs (19) and (20) being connected to corresponding inputs (3) and (4) of input differential stage (1).

EFFECT: increased common mode rejection factor.

6 dwg