METHOD AND APPARATUS FOR DETECTING A TOUCH ON A DEVICE

A method and circuitry for detecting a touch on a device is provided herein. Touch-sensing circuitry comprises two antennas coupled to two voltage-controlled oscillators (VCOs). A phase locked loop (PLL) is provided coupled to the VCOs. The PLL compares a VCO output with a frequency source (temperature controlled crystal oscillator (TCXO)), and outputs a tuning voltage (steering voltage) for the VCO that is based on the difference between the VCO frequency and the TCXO frequency. The steering voltages for each VCO are compared, and a decision is made as to whether or not a touch has been made to the antennas. If the antennas have been touched, a location of the touch is determined based on a difference in the steering voltages of the two VCOs.