This video explains the amplifiers utilized in current sensors. Direct current sensors use the following differential input amplifiers to increase the minimal sense voltage.
Operational amplifiers provide the most fundamental implementation and are ideal in applications requiring less accuracy and a lower cost. Nevertheless, using high-accuracy external components to enhance precision, cancels out the costs.
Since the common-mode voltage of an operational amplifier is only as high as its supply voltage, these are most effective when used for limited quantification.
Difference amplifiers are ideal for transforming low-level differential signals into high-level single-ended signals. The layout works well for the large majority of current sensing uses.
Instrumentation amplifiers are a combo of a difference amplifier and a buffer level on each input variable. Due to the extremely high internal resistance, even they can measure shallow currents accurately. However, the design restricts its use to situations where the constant voltage output is compatible with the source voltage.
Amplifiers that sense current are specialized amplifiers with their distinct input stage, which allows the constant voltage output to be significantly higher than the voltage source of the amplifier. They also incorporate low-drift gain connectivity for maximum precision in measurements.