A switching apparatus for switching between different supply voltages of a digital structure, suitable for use in an envelop tracking system for a radio frequency power amplifier, the switching apparatus comprising: a plurality of switching load cells configured to operate either at a first voltage or at a lower second voltage, depending on a respective bit of a digital control signal, each switching load cell comprising: a charging capacitor; a first switch; a second switch and a third switch, said first switch coupled between ground and said second switch, said charging capacitor coupled between node between said first switch and said second switch and ground, said second switch coupled between said charging capacitor and said third switch, and said third switch coupled between said second switch and a supply voltage; and an output node (VOUT LS) coupled between said second and third switches (312,316) and coupled to a load capacitance; a fourth switch, coupled between said output node (VOUT LS) and a voltage regulator; wherein the control signal for each of the first, second, third and fourth switch is a function of the digital control signal; wherein said output node is configured to be charged to a first voltage in response to the third switch being closed and the second switch and the fourth switch being open; wherein the charging capacitor is configured to discharge in response to the first switch being closed and the second switch being open, and to charge in response to being connected to said output node by means of the first switch being open and the second switch being closed, where said output node has been disconnected from the supply voltage by means of the third switch switch being open; and wherein the voltage regulator is configured to connect to said output node in response to said charging capacitor being disconnected from the output node by means of the fourth switch being closed and the second switch and the third switch being open, and further configured to regulate the output node to the second voltage, wherein the ratio of the load capacitance to the charging capacitor is based on a ratio of the second voltage divided by the difference between the first voltage and the second voltage. a plurality of switching load cells configured to operate either at a first voltage or at a lower second voltage, depending on a respective bit of a digital control signal, each switching load cell comprising: a charging capacitor; a first switch; a second switch and a third switch, said first switch coupled between ground and said second switch, said charging capacitor coupled between node between said first switch and said second switch and ground, said second switch coupled between said charging capacitor and said third switch, and said third switch coupled between said second switch and a supply voltage; and an output node (VOUT LS) coupled between said second and third switches (312,316) and coupled to a load capacitance; a fourth switch, coupled between said output node (VOUT LS) and a voltage regulator; a charging capacitor; a first switch; a second switch and a third switch, said first switch coupled between ground and said second switch, said charging capacitor coupled between node between said first switch and said second switch and ground, said second switch coupled between said charging capacitor and said third switch, and said third switch coupled between said second switch and a supply voltage; and an output node (VOUT LS) coupled between said second and third switches (312,316) and coupled to a load capacitance; a fourth switch, coupled between said output node (VOUT LS) and a voltage regulator; wherein the control signal for each of the first, second, third and fourth switch is a function of the digital control signal; wherein said output node is configured to be charged to a first voltage in response to the third switch being closed and the second switch and the fourth switch being open; wherein the charging capacitor is configured to discharge in response to the first switch being closed and the second switch being open, and to charge in response to being connected to said output node by means of the first switch being open and the second switch being closed, where said output node has been disconnected from the supply voltage by means of the third switch switch being open; and wherein the voltage regulator is configured to connect to said output node in response to said charging capacitor being disconnected from the output node by means of the fourth switch being closed and the second switch and the third switch being open, and further configured to regulate the output node to the second voltage, wherein the ratio of the load capacitance to the charging capacitor is based on a ratio of the second voltage divided by the difference between the first voltage and the second voltage.