CASCODE DIFFERENTIAL AMPLIFIER WITH INCREASED ZERO LEVEL STABILITY Russian patent published in 2011 - IPC H03F3/45 

FIELD: radio engineering.

SUBSTANCE: cascode differential amplifier includes input differential cascade (1) with the first (2) and the second (3) current outputs, current mirror (4) having the first (5) and the second (6) emitter inputs, base (7) input and current output (8), the first (5) emitter input of current mirror (4) is connected to the first (2) current output of input differential cascade (1), and the second (6) emitter input of current mirror (4) is connected to the second (3) current output of input differential cascade (1), base (7) input of current mirror (4) is connected to collector of the first (9) auxiliary transistor, current output (8) of current mirror (4) is connected to collector of the second (10) auxiliary transistor; bases of the first (9) and the second (10) auxiliary transistors are connected to each other and connected to offset voltage source (11); base of input transistor of output emitter repeater (12) is connected to collector of the second (10) auxiliary transistor, and its emitter is connected to output of device (13). At that, emitters of the first (9) and the second (10) auxiliary transistors are connected to the first (14) power supply through the first (15), the second (16) auxiliary resistors. To the circuit there introduced is additional transistor (17) the collector of which is connected to output (13) of the device; base is connected to emitter of the first (9) auxiliary transistor; emitter is connected through the first 18 additional resistor to the first (14) power supply, and collector of input transistor of output emitter repeater (12) is connected to the second (19) power supply; at that, all auxiliary (9), (10) and additional (17) transistors have one type of conductivity.

EFFECT: decreasing zero offset voltage U_offset and its drift in conditions of temperature and radiation effects.

3 cl, 5 dwg