A mobile device comprising: a plurality of power amplifiers (32a-c, 92a-b, 102a-e, 103a-e) including first and second power amplifiers (32a, 32b, 92a, 92b, 102a, 102b, 103a, 103b) configured to amplify respective first and second radio frequency, RF, signals that have time-varying envelopes, the first and second power amplifiers each having an enabled state and a disabled state; an envelope tracking module configured to generate a supply voltage (V CC_PA) for a first supply node used to electrically power the plurality of power amplifiers (32a-c, 92a-b, 102a-e, 103a-e), the envelope tracking module being configured to vary the supply voltage (V CC_PA) based on the envelope of the first RF signal if the first power amplifier (32a, 92a, 102a, 103a) is enabled or based on the envelope of the second RF signal if the second power amplifier (32b, 92b, 102b, 103b) is enabled; first and second capacitors (74a, 74b, 85a, 85b, 104a, 104b, 124a, 124b), each capacitor having a first end and a second end, the first end of each capacitor being electrically connected to the first supply node; a first switch (71a, 94a, 101a, 121a) connected between the second end of the first capacitor (74a, 85a, 104a, 124a) and a second supply node (Vi), the first switch (71a, 94a, 101a, 121a) configured to open in response to the first power amplifier (32a, 92a, 102a, 103a) being disabled and to close in response to the first power amplifier (32a, 92a, 102a, 103a) being enabled; and a second switch (71b, 94b, 101b, 121b) connected between the second end of the second capacitor (74b, 85b, 104b, 124b) and the second supply node (Vi), the second switch (71b, 94b, 101b, 121b) configured to open in response to the second power amplifier (32b, 92b, 102b, 103b) being disabled and to close in response to the second power amplifier (32b, 92b, 102b, 103b) being enabled. a plurality of power amplifiers (32a-c, 92a-b, 102a-e, 103a-e) including first and second power amplifiers (32a, 32b, 92a, 92b, 102a, 102b, 103a, 103b) configured to amplify respective first and second radio frequency, RF, signals that have time-varying envelopes, the first and second power amplifiers each having an enabled state and a disabled state; an envelope tracking module configured to generate a supply voltage (V CC_PA) for a first supply node used to electrically power the plurality of power amplifiers (32a-c, 92a-b, 102a-e, 103a-e), the envelope tracking module being configured to vary the supply voltage (V CC_PA) based on the envelope of the first RF signal if the first power amplifier (32a, 92a, 102a, 103a) is enabled or based on the envelope of the second RF signal if the second power amplifier (32b, 92b, 102b, 103b) is enabled; first and second capacitors (74a, 74b, 85a, 85b, 104a, 104b, 124a, 124b), each capacitor having a first end and a second end, the first end of each capacitor being electrically connected to the first supply node; a first switch (71a, 94a, 101a, 121a) connected between the second end of the first capacitor (74a, 85a, 104a, 124a) and a second supply node (Vi), the first switch (71a, 94a, 101a, 121a) configured to open in response to the first power amplifier (32a, 92a, 102a, 103a) being disabled and to close in response to the first power amplifier (32a, 92a, 102a, 103a) being enabled; and a second switch (71b, 94b, 101b, 121b) connected between the second end of the second capacitor (74b, 85b, 104b, 124b) and the second supply node (Vi), the second switch (71b, 94b, 101b, 121b) configured to open in response to the second power amplifier (32b, 92b, 102b, 103b) being disabled and to close in response to the second power amplifier (32b, 92b, 102b, 103b) being enabled.