A mobile device has a proximity sensor. A compensation value of the proximity sensor is determined. The compensation value is compared to a reference compensation value to determine validity of the compensation value. A capacitance of the proximity sensor is measured. A value of the capacitance of the proximity sensor is adjusted based on the compensation value. A coefficient defining a relationship between a capacitance of the proximity sensor and a temperature of the mobile device is calculated. A temperature sensor is coupled to the proximity sensor. The temperature of the mobile device is measured. A value of the capacitance of the proximity sensor is adjusted based on the coefficient and the temperature of the mobile device. The adjusted capacitance value is compared to a threshold capacitance value to determine proximity of an object to the mobile device. A radio frequency signal is adjusted by detecting proximity.

A method of operating a signal isolation device includes receiving an input signal at an input of a transmit die and in response, generating a corresponding time varying electrical voltage at a transmitter output of the transmit die. The time varying electrical voltage is coupled to a transmit coil disposed within a receiver die. A receive coil is induced to generate an intermediate signal in response to the coupling of the time varying electrical voltage to the transmit coil, wherein the intermediate signal corresponds to the input signal. The intermediate signal is coupled to receiver circuitry disposed within the receiver die. Electromagnetic noise generated by the receive coil is shielded from the receiver circuitry via a shield positioned between the receive coil and the receiver circuitry.

A solid-state relay device includes a transistor die, a transmitter die including a pair of input terminals coupled to a pair of transmitter output terminals and a receiver die including a pair of receiver input terminals, a pair of output terminals and a coupler region. The transmitter die is attached to a top surface of the receiver die, wherein at least one output terminal of the pair of output terminals is attached to a gate terminal of the transistor die. The coupler region includes: a transmit coil connected to the pair of receiver input terminals; a receiver coil positioned proximate the transmit coil and connected to the pair of output terminals; receiver circuitry; and a shield layer positioned between the receiver circuitry and the receiver coil.