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 . <EOS>