DIFFERENTIAL AMPLIFIER WITH MINOR ZERO OFFSET VOLTAGE Russian patent published in 2008 - IPC H03F3/45 

FIELD: electricity.

SUBSTANCE: invention may be used within the structure of different functional analogue microchips. Differential amplifier with minor zero offset voltage includes complementary input differential stage (1) having anti-phase current outputs 1 (2) and 2 (3) matched with positive power supply bus (4), anti-phase current outputs 3 (5) and 4 (6) matched with negative power supply bus (7), output transistors 1 (8) and 2 (9), with integrated bases connected to offset voltage source (10), transistor collector (8) linked with current mirror (12) input (11). Current mirror output (13) is coupled with transistor collector (9) and differential amplifier output (14), input differential stage (1) current outputs 1 (2) and 2 (3) being linked with emitters of output transistors 1 (8) and 2 (9) and corresponding current-stabilising impedors (15) and (16). Circuit includes additional current mirror (17) with input connected to input differential stage (1) current output 3 (5), while current mirror output is connected to input differential stage (1) current output 4 (6) and current mirror 1 (12) input (1).

EFFECT: decrease in zero offset voltage within wide range of current transfer ratio for current mirrors.

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