DIFFERENTIAL AMPLIFIER OF AB CLASS Russian patent published in 2008 - IPC H03F3/45 

FIELD: electricity.

SUBSTANCE: invention may be used for analogue signal amplification 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 (3) having current outputs 1 (4) and 2 (3), active load impedor 1 (6) and 2 (7), feedback circuit transistor 1 (8) and output transistor (9) with their bases integrated and connected to input differential stage (1) current output (4) and active load impedor 1 (6). Emitters are linked with power supply 1 bus (10). Feedback circuit transistor 2 (11) and output transistor (12) have their bases integrated and connected to input differential stage (1) current output (5) and active load impedor 2 (7). Emitters are linked with power supply 1 bus (10). Output current mirror (13) has its input connected to transistor collector (9) and output connected to transistor collector (12) and differential amplifier output (14). Also, transistor collector (8) and feedback circuit transistor (11) are joined with common emitting circuit (3) of input differential stage (1). Circuit is supplemented with auxiliary resistors 1 (15) and 2 (16) and auxiliary transistors 1 (17) and 2 (18), feedback circuit transistor collectors (8 and 11) being linked with emitting circuit (3) of input differential stage (1) resistor (15 and 16). Transistor base (17) is connected to feedback circuit transistor collector (8) and transistor emitter (18). Emitter is linked with transistor base (18) and feedback circuit transistor collector (11), transistor collectors (17 and 18) being coupled with power supply bus.

EFFECT: increase in maximum output current of differential amplifier while preserving high stability of through current within operating temperatures range and instability of voltage source.

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