A near field communications integrated circuit for a mobile communications device, the integrated circuit comprising: a power supply rail for providing a regulated supply of power to components within the integrated circuit; a first transistor coupled between the power supply rail and a power supply output of the integrated circuit for selectively providing power to a universal integrated circuit card (UICC) of the mobile communications device from the power supply rail while the mobile communications device is in an off state; and a current control circuit for controlling the operation of the first transistor to prevent a drop in voltage on the power supply rail as the first transistor is switched to an on state to couple the power supply rail to the power supply output, characterised in that the current control circuit comprises: a first switch; a second switch, wherein a gate of the first transistor is coupleable to reference potential via the second switch; a second transistor having a gate coupleable to the gate of the first transistor via the first switch, and a third transistor and a fourth transistor, wherein a gate of the third transistor is coupled to a gate of the fourth transistor, wherein the second transistor and the fourth transistor are coupled in series between the power supply rail and a first current source, the second transistor being coupled to the power supply rail and the fourth transistor being coupled to the first current source, wherein the first transistor and the third transistor are coupled in series between the power supply rail and a second current source, the first transistor being coupled to the power supply rail and the third transistor being coupled to the second current source, wherein a node located between the fourth transistor and the first current source is coupled to a node located between the gate of the second transistor and the first switch, and wherein a node located between the third transistor and the second current source is coupled to the gates of the third transistor and fourth transistor. a power supply rail for providing a regulated supply of power to components within the integrated circuit; a first transistor coupled between the power supply rail and a power supply output of the integrated circuit for selectively providing power to a universal integrated circuit card (UICC) of the mobile communications device from the power supply rail while the mobile communications device is in an off state; and a current control circuit for controlling the operation of the first transistor to prevent a drop in voltage on the power supply rail as the first transistor is switched to an on state to couple the power supply rail to the power supply output, characterised in that the current control circuit comprises: a first switch; a second switch, wherein a gate of the first transistor is coupleable to reference potential via the second switch; a second transistor having a gate coupleable to the gate of the first transistor via the first switch, and a third transistor and a fourth transistor, wherein a gate of the third transistor is coupled to a gate of the fourth transistor, wherein the second transistor and the fourth transistor are coupled in series between the power supply rail and a first current source, the second transistor being coupled to the power supply rail and the fourth transistor being coupled to the first current source, wherein the first transistor and the third transistor are coupled in series between the power supply rail and a second current source, the first transistor being coupled to the power supply rail and the third transistor being coupled to the second current source, wherein a node located between the fourth transistor and the first current source is coupled to a node located between the gate of the second transistor and the first switch, and wherein a node located between the third transistor and the second current source is coupled to the gates of the third transistor and fourth transistor. a first switch; a second switch, wherein a gate of the first transistor is coupleable to reference potential via the second switch; a second transistor having a gate coupleable to the gate of the first transistor via the first switch, and a third transistor and a fourth transistor, wherein a gate of the third transistor is coupled to a gate of the fourth transistor, wherein the second transistor and the fourth transistor are coupled in series between the power supply rail and a first current source, the second transistor being coupled to the power supply rail and the fourth transistor being coupled to the first current source, wherein the first transistor and the third transistor are coupled in series between the power supply rail and a second current source, the first transistor being coupled to the power supply rail and the third transistor being coupled to the second current source, wherein a node located between the fourth transistor and the first current source is coupled to a node located between the gate of the second transistor and the first switch, and wherein a node located between the third transistor and the second current source is coupled to the gates of the third transistor and fourth transistor.