Capacitive and temperature-compensated proximity sensor and method

Abstract

Electronic device (115, 1800) comprising: a sensor arrangement (100) comprising: a proximity sensor having a proximity pad (102) and a second reference pad (106), a temperature sensor having a first reference pad (104) and a temperature pad (108), and a controller (120) electrically coupled to the sensor arrangement (100), wherein the proximity pad (102) is located between a user-facing surface (105) of the electronic device (115, 1800) and the second reference pad (106), the first reference pad (104) is located between the user-facing surface (105) and the temperature pad (108), and wherein the sensor arrangement (100) is contained in fewer than four circuit layers.the sensor arrangement (100) is configured to generate a proximity sensor capacity value using the proximity pad (102) and the sensor arrangement (100) is configured to generate a temperature sensor capacity value using the temperature pad (108); the controller (120) is configured to adjust a baseline proximity sensor value, which is used to determine whether a user is near the electronic device (115, 1800) or not, based on the temperature sensor capacity value; and adjusting the baseline proximity sensor value when a user is indicated as being near the electronic device (115, 1800) involves setting the baseline proximity sensor value equal to the proximity sensor capacity value minus a proximity sensor capacity threshold.