CASCODE DIFFERENTIAL AMPLIFIER Russian patent published in 2011 - IPC H03F3/45 

FIELD: electricity.

SUBSTANCE: cascode differential amplifier includes input differential cascade (DC) (1) with the first (2) and the second (3) current outputs, the first (4) and the second (5) output transistors (T) the bases of which are connected to offset voltage source (6); emitter of the first (4) output T is connected to the first (2) current output of DC (1); emitter of the second (5) output T is connected to the second (3) current output of DC (1); the first (7) resistor of collector load connected through the first output to the first (8) output of device and collector of the first (4) output T; the second (9) resistor of collector load connected through the first output to the second (10) output of device and collector of the second (5) output T; the first (11) and the second (12) power sources (PS); at that, emitter power supply circuit of DC (1) is connected to the second (12) PS. To the diagram there introduced is the first (13) and the second (14) current mirrors the common emitter outputs of which are connected to the first (11) PS; input of the first (13) current mirror is connected to the second output of the first (7) resistor of collector load; input of the second (14) current mirror is connected to the second output of the second (9) resistor of collector load; output of the first (13) current mirror is connected to the second (3) current output of DC (1), and output of the second (14) current mirror is connected to the first (2) current output of DC (1).

EFFECT: increasing amplification coefficient as to voltage when using relatively low-ohmic resistors of collector load in conditions of SiGe-technology limits for power supply voltages.

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