Abstract: There is disclosed an improved differential amplifier (20) having a feedback loop that generates an amplified output signal (Vout) from an input signal (Vin) supplied by a preceding stage. It comprises an input matching circuit (11) connected to said preceding stage, a buffer (22) and an amplification section (12) connected in series in the direct amplification line, a first amplifier (16), a RC network (17?) and a second amplifier (23) connected in series in a parallel loop between the outputs and the inputs of the amplification section that generate the feedback signal. The role of said buffer and second amplifier associated in a dedicated direct and feedback signal combining block (21) is to respectively isolate the input signal and the feedback signal from the summing nodes (A?,B?) at the amplification section inputs. As a result, the summation of the input signal and the feedback signal is improved, the DC component of the output signal is filtered out in order to significantly reduce the DC offset.

Abstract: There is disclosed an improved 2-stage large bandwidth amplifier (20) comprised of two stages formed by first and second bipolar transistors (Q1,Q2) configured in common emitter that are connected in series with their emitters connected to a first supply voltage (Gnd). The input signal (Vin) is applied to the base of said first transistor via an input terminal (11), while the output signal (Vout) is available at an output terminal (12) connected to the collector of said second transistor. A parallel feedback structure (13?) is provided. It consists, in a first branch, of two diodes (D1,D2) in series connected between a second supply voltage (Vcc) and the collector of the second bipolar transistor, and in another branch of a third bipolar transistor (Q3) configured in emitter follower with a resistor (Rf) in the emitter. The base and the collector of said third bipolar transistor are respectively connected to the common node of said diodes and to said second supply voltage.

Abstract: There is disclosed an improved 2-stage large bandwidth amplifier (20) comprised of two stages formed by first and second bipolar transistors (Q1,Q2) configured in common emitter that are connected in series with their emitters connected to a first supply voltage (Gnd). The input signal (Vin) is applied to the base of said first transistor via an input terminal (11), while the output signal (Vout) is available at an output terminal (12) connected to the collector of said second transistor. A parallel feedback structure (13′) is provided. It consists, in a first branch, of two diodes (D1,D2) in series connected between a second supply voltage (Vcc) and the collector of the second bipolar transistor, and in another branch of a third bipolar transistor (Q3) configured in emitter follower with a resistor (Rf) in the emitter. The base and the collector of said third bipolar transistor are respectively connected to the common node of said diodes and to said second supply voltage.