OPERATIONAL AMPLIFIER WITH LOW VOLTAGE OF ZERO SHIFT Russian patent published in 2011 - IPC H03F3/45 

FIELD: radio engineering.

SUBSTANCE: operational amplifier with low voltage of zero shift comprises input differential cascade (1), having the first (2) and second (3) current outputs, p-n transition of active load (4), joined by the first input to bases of the first (5) and second (6) output transistors and the first (2) current output of input differential cascade (1), the third (7) output transistor, base of which is joined to the second (3) current output of input differential cascade (1) and collector of the first (5) output transistor, the first (8) source of supply joined to emitters of the first (5), second (6) and third (7) output transistors and the second output of p-n transition of active load (4), current mirror (9), matched with the second (10) source of supply, output of which is connected to input of circuit of output signal extraction (11). Collector of the second (6) output transistor is connected to emitter of the first (12) additional transistor, base of the first (12) additional transistor is connected to the base of the second (13) additional transistor and source of shift voltage (14), collector of the first (12) additional transistor is joined to input of current mirror (9), emitter of the second (13) additional transistor is connected to collector of the third (7) output transistor, and collector of the second (13) additional transistor is connected to output of current mirror (9), besides, coefficient of transfer by current of current mirror (9) is close to three units (_Ki12.9=-3).

EFFECT: reduced systematic component of zero shift voltage U_CM.

2 cl, 6 dwg