A sensor circuit for a vehicle including a regulator control circuit, a switching regulator, and at least one analogue sensor connected to an output of the switching regulator, wherein the regulator control circuit is configured to control the switching regulator and includes: a feedback comparator configured to compare a signal representative of a reference voltage with a signal representative of a voltage output of the switching regulator and to output a control signal for controlling the operation of the switching regulator dependent on the signals received by the feedback comparator, wherein the analogue sensor is provided with power at a voltage which tracks the reference voltage and wherein the analogue sensor is configured to sense a parameter associated with the operation of the vehicle; and a current feedback controller connected to the feedback comparator and configured to receive a signal representative of a current output by the switching regulator and determine whether the regulator control circuit adopts a first or second mode of operation based on the signal representative of a current output, such that: in the first mode of operation, the control signal is for controlling the switching regulator in accordance with a constant voltage control scheme, and in the second mode of operation, the control signal is for controlling the switching regulator in accordance with a constant current control scheme, characterized in that the signal representative of the reference voltage is a signal representative of a reference voltage of an analogue-to-digital converter which is configured to receive an output from the at least one analogue sensor. a feedback comparator configured to compare a signal representative of a reference voltage with a signal representative of a voltage output of the switching regulator and to output a control signal for controlling the operation of the switching regulator dependent on the signals received by the feedback comparator, wherein the analogue sensor is provided with power at a voltage which tracks the reference voltage and wherein the analogue sensor is configured to sense a parameter associated with the operation of the vehicle; and a current feedback controller connected to the feedback comparator and configured to receive a signal representative of a current output by the switching regulator and determine whether the regulator control circuit adopts a first or second mode of operation based on the signal representative of a current output, such that: in the first mode of operation, the control signal is for controlling the switching regulator in accordance with a constant voltage control scheme, and in the second mode of operation, the control signal is for controlling the switching regulator in accordance with a constant current control scheme, characterized in that the signal representative of the reference voltage is a signal representative of a reference voltage of an analogue-to-digital converter which is configured to receive an output from the at least one analogue sensor. in the first mode of operation, the control signal is for controlling the switching regulator in accordance with a constant voltage control scheme, and in the second mode of operation, the control signal is for controlling the switching regulator in accordance with a constant current control scheme, characterized in that the signal representative of the reference voltage is a signal representative of a reference voltage of an analogue-to-digital converter which is configured to receive an output from the at least one analogue sensor.