BUFFER AMPLIFIER WITH LOW ZERO-SHIFT VOLTAGE Russian patent published in 2010 - IPC H03F3/45 

FIELD: radio engineering.

SUBSTANCE: invention can be used as a wideband signal amplifier in various-purpose analog microcircuits (for example, comparators and precision operating amplifiers with low zero-shift e.m.f). Proposed differential amplifier (DA) comprises input differential stage (DS) (1) with its first (2) current mirror (CM) input (3). Second current output (4) is connected with CM output and input (5) of buffer amplifier (BA) (6). It comprises also output transistor (7) of reference current source with its collector connected with common emitter circuit (8) of DS (1), while emitter is connected via first (9) current-stabilising bipolar transistor with power supply bus (10).Note here that conductance type of BA input resistor (11) complies with that of reference current source of transistor (7). Reference current source transistor (7) base is connected with the input of additional non-inverting current follower (12) with its AC output is connected with first (2) DS current output.

EFFECT: decreased zero-shift voltage.

6 cl, 7 dwg