CASCODE DIFFERENTIAL AMPLIFIER WITH INCREASED INPUT RESISTANCE Russian patent published in 2010 - IPC H03F3/45 H03F1/56 

FIELD: radio engineering.

SUBSTANCE: cascode differential amplifier (CDA) includes input parallel-balance cascade (PBC) (1) having the first (2) and the second (3) inputs, the first (4) and the second (5) current outputs connected to emitters of first (6) and second (7) output transistors (T) the bases of which are combined and connected to offset voltage source (OVS) (8), and collectors are connected to load circuit (9), additional current divider (CD) (10) having the main input (11), as well as first (12) and second (13) outputs connected to the appropriate first (2) and second (3) PBC (1) inputs. PBC (1) includes the first (12) additional current output cophasal with current output (4), second (13) additional current output cophasal with current output (5); at that, current outputs (12) and (13) are connected to emitter of the first additional T (14) the base of which is connected to OVS (8), and collector is connected to emitter of second (15) additional T; base of T (15) is connected to input (16) of auxiliary current mirror (17) the output of which is connected to input (11) of CD (10).

EFFECT: increasing input resistance.

5 cl, 11 dwg