Semtech Corporation

Hehai Zheng

Chaouki Rouaissia

A capacitive proximity sensor for use in mobile devices such as smartphones and connected tables, in which it is used to switch off a display () when the device is brought to the ear. The capacitive sensor is arranged for rejecting spurious detection induced, for example, by condensation, ingress of water, or thermal drift, based on the time variations of a capacity seen by the readout circuit (), Additionally, the proximity sensor may integrate signals form motion sensors, temperature sensors or other sensors, to discriminate spurious proximity signals.

Intelligent proximity detector

A capacitive proximity sensor for use in mobile devices such as smartphones and connected tables, in which it is used to switch off a display () when the device is brought to the ear, and to reduce selectively the RF power when the device is in close proximity to a body part of a user, in order to fulfil regulatory SAR limits. The capacitive sensor uses two electrodes (), the first of which may also serve as RF antenna, and the other is preferably on the back of the phone and is opposite the display.

Growing community of inventors

Province, China

Hehai Zheng