DIFFERENTIAL AMPLIFIER WITH SYMMETRICAL LOAD Russian patent published in 2010 - IPC H03F3/45 H03F1/56 

FIELD: radio engineering.

SUBSTANCE: differential amplifier (DA) includes input parallel-balance cascade (PBC) (1) having the first (2) and the second (3) inputs, the first (4) and the second (5) main outputs connected to the appropriate first (6) and second (7) load circuits; first (8) and second (9) auxiliary transistors (T) the bases of which are connected to the appropriate inputs (2) and (3) of PBC (1), and emitters are connected to each other and connected to output (10) of auxiliary current mirror (CM) (11). PBC (1) includes first (12) additional current output cophasal with output (4), second (13) additional current output cophasal with current output (5); at that, current outputs (12) and (13) are connected to emitter of first (14) additional T; base of T (14) is connected to output (15) of cophasal signal extraction circuit (16); collector is connected to emitter of second 17 additional transistor; at that, base of second 17 additional T is connected to input of CM (11); collector of T (8) is connected to input (3) of PBC (1), and collector of T (9) is connected to input (2) of PBC (1).

EFFECT: increasing input resistance.

5 cl, 10 dwg