Patent ID: 8841906

Claim:
A current sensor for detecting a currentless state, the current sensor comprising: a magnetic field sensor; a variable supply connected to the magnetic field sensor; a first differential amplifier connected to the magnetic field sensor, the first differential amplifier amplifying a first sensor voltage, the first differential amplifier having an output that provides an amplified analog sensor voltage; and a second differential amplifier connected to the supply, the second differential amplifier having a first input and a second input, wherein the first input of the second differential amplifier is connected directly to the output of the first differential amplifier and the second input of the second differential amplifier is connected to a reference voltage so that the amplified analog sensor voltage is provided at the first input of the second differential amplifier, wherein the first differential amplifier, the second differential amplifier, and the magnetic field sensor with the variable supply form an analog control loop; wherein, in the case of the first sensor voltage, a first operating current or a first supply voltage is provided at the magnetic field sensor, and, in the case of a second sensor voltage, a second operating current or a second supply voltage is provided, and wherein the second sensor voltage is smaller than the first sensor voltage and the second operating current or the second supply voltage is greater than the first operating current or the first supply voltage.