Monolithically-integrated current-feedback instrumentation amplifier and sensing system comprising said amplifier

A monolithically-integrated current-feedback instrumentation amplifier comprising:

• a first differential pair of transistors (M1, M2) configured for receiving a differential input signal (Vin+, Vin−) on gate or base terminals of said transistors (M1, M2);
• a second differential pair of transistors (M3, M4) configured for receiving a differential feedback signal (Vfb+, Vfb−) on gate or base terminals of said transistors (M3, M4);
• wherein a drain or collector terminal of a first transistor (M1) of the first differential pair (M1, M2) is directly connected to a drain or collector terminal of a first transistor (M3) of the second differential pair (M3, M4) and to a non-inverting, high-impedance input terminal of a differential voltage amplifier, and is connected to a ground terminal by means of a first sink resistor (Rsink);
• and a drain or collector terminal of a second transistor (M2) of the first differential pair (M1, M2) is directly connected to a drain or collector terminal of a second transistor (M4) of the second differential pair (M3, M4) and to an inverting, high-impedance input terminal of the differential voltage amplifier, and is connected to a ground terminal by means of a second sink resistor (Rsink);
• and wherein an output terminal of the differential voltage amplifier, serving as an output terminal of the current-feedback instrumentation amplifier, is connected to a resistive voltage divider providing said differential feedback signal (Vfb+, Vfb−);
• wherein source or emitter terminals of the transistors of the first differential pair (M1, M2) are directly connected together and to a first bias current source without a degeneration resistor, and source or emitter terminals of the transistors of the second differential pair (M3, M4) are directly connected together and to a second bias current source also without a degeneration resistor.