CASCODE DIFFERENTIAL AMPLIFIER Russian patent published in 2012 - IPC H03F3/34 

FIELD: radio engineering.

SUBSTANCE: cascode differential amplifier has an input differential stage (1) with a first (2) and a second (3) current output, a first (5) and a second (6) output transistor, whose bases are connected to an auxiliary power supply (7); the collector of the first (5) output transistor is connected to the output of the device (8) and the first lead of the first (9) load resistor; the collector of the second (6) output transistor is connected to the output of the device (10) and the first lead of the second (11) load resistor; a second (12) power supply bus. The circuit includes a first (13) and a second (14) current mirror; the common emitter output of the first (13) current mirror is connected to the emitter of the first (5) output transistor; the common emitter output of the second (14) current mirror is connected to the emitter of the second (6) output transistor; current outputs of the first (13) and second (14) current mirrors are connected to the power supply (15); the second lead of the first (9) load resistor is connected through a first (16) additional resistor to the second (12) power supply bus and through a first (17) balancing capacitor to the first (2) current output of the input differential stage (1) and the input of the first (13) current mirror; the second lead of the second (11) load resistor is connected through a second (18) additional resistor to the second (12) power supply bus and through a second (19) balancing capacitor to the second (3) current output of the input differential cascade (1) and the input of the second (14) current mirror.

EFFECT: high voltage gain.

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