Differential amplifier comprising an unlocking device

A differential amplifier having two input electrodes (E1, E2), two output electrodes (O1, O2) and comprising:

• a first stage comprised of first and second transistors (10, 20) of identical polarity and assembled so as to constitute a differential amplifier, said first and second transistors being fed by first and second mirror current sources (11, 21) respectively, the current of which is controlled by a control circuit supporting common mode (2, 3, 4, 5) and having two inputs receiving a reference value VCM and an electrode's voltage representative of the common mode voltage of said outputs (O1, O2);
• a second Miller stage, the inputs of which are connected to said output electrodes (O1, O2), said second stage comprising third and fourth transistors (12, 22) both of opposite-type from the former, the inputs of which receive output signals from said first stage, characterised in that the circuit comprises:
• an unlocking circuit (18, 28) which is inserted between said voltage representative of the common mode voltage and said Miller stage inputs, in order to cause a resistive short-circuit and ensure conduction of said third and fourth transistors so as to initiate startup of the differential amplifier circuit.