DIFFERENTIAL AMPLIFIER Russian patent published in 2010 - IPC H03F3/45 

FIELD: radio engineering.

SUBSTANCE: invention can be used as a device for amplifying analogue signals, in analogue microcircuits for various functional purposes (e.g. in comparators and precision operational amplifiers with small zero offset emf values). The differential amplifier has a first (1) and a second (2) input transistor, between emitters of which a local negative feedback resistor (3) is connected, a first (4) current stabilising two-terminal element connected to the emitter of the first (1) input transistor, a second (5) current stabilising two-terminal element connected to the emitter of the second (2) input transistor, a third (6) current stabilising two-terminal element connected to the collector of the first (1) input transistor and the emitter of the first (7) output transistor, whose base is connected to the emitter of the first (1) input transistor, a fourth (8) current stabilising two-terminal element (8) connected to the collector of the second (2) input transistor and the emitter of the second (9) output transistor, a current mirror (10) whose input is connected to the collector of the first (7) output transistor, while the output is connected to the collector of the second (9) output transistor and the base of the input transistor (11) of the buffer amplifier (12). The base of the second (9) output transistor is connected to the base of the first (7) output transistor. Conductivity type of the input transistor (11) of the buffer amplifier (12) is the same as that of the first (7) and second (9) output transistors.

EFFECT: low absolute value zero offset emf U_off and its temperature drift.

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