An apparatus for charging and controlling a wearable device comprising: a first p-type field effect transistor, PFET, having a first source connected to a device voltage terminal (SYSTEM_V), a first gate connected to a second input path (PWR_IN_2), and a drain connected to a first input path (PWR_IN_1), the first input path (PWR_IN_1) and the second input path (PWR_IN_2) being configured to connect to a power supply; a second PFET having a second source connected to the device voltage terminal (SYSTEM_V), a second gate connected to the first input path (PWR_IN_1), and a second drain connected to the second input path (PWR_IN_2); a first n-type field effect transistor, NFET, having a third source connected to a device ground, a third gate connected to the second input path (PWR_IN_2), and a third drain connected to the first input path (PWR_IN_1); and a second NFET having a further source connected to the device ground, a fourth gate connected to the first input path (PWR_IN_1), and a fourth drain connected to the second input path (PWR_IN_2), characterized in that the apparatus further comprises: a third NFET having a source connected to a first communication path coupled to control circuitry of the wearable device, a gate connected to a control input configured for selecting between a charging mode and a communication mode of the apparatus, and a drain connected to the first input path (PWR_IN_1), and a fourth NFET having a source connected to the control input, a gate connected to the device ground, and a drain connected to the second input path (PWR_IN_2). a first p-type field effect transistor, PFET, having a first source connected to a device voltage terminal (SYSTEM_V), a first gate connected to a second input path (PWR_IN_2), and a drain connected to a first input path (PWR_IN_1), the first input path (PWR_IN_1) and the second input path (PWR_IN_2) being configured to connect to a power supply; a second PFET having a second source connected to the device voltage terminal (SYSTEM_V), a second gate connected to the first input path (PWR_IN_1), and a second drain connected to the second input path (PWR_IN_2); a first n-type field effect transistor, NFET, having a third source connected to a device ground, a third gate connected to the second input path (PWR_IN_2), and a third drain connected to the first input path (PWR_IN_1); and a second NFET having a further source connected to the device ground, a fourth gate connected to the first input path (PWR_IN_1), and a fourth drain connected to the second input path (PWR_IN_2), characterized in that the apparatus further comprises: a third NFET having a source connected to a first communication path coupled to control circuitry of the wearable device, a gate connected to a control input configured for selecting between a charging mode and a communication mode of the apparatus, and a drain connected to the first input path (PWR_IN_1), and a fourth NFET having a source connected to the control input, a gate connected to the device ground, and a drain connected to the second input path (PWR_IN_2). a third NFET having a source connected to a first communication path coupled to control circuitry of the wearable device, a gate connected to a control input configured for selecting between a charging mode and a communication mode of the apparatus, and a drain connected to the first input path (PWR_IN_1), and a fourth NFET having a source connected to the control input, a gate connected to the device ground, and a drain connected to the second input path (PWR_IN_2).