Optical sensor with logic for gesture recognition

June 28, 2016 // By Peter Clarke
Analog Devices has introduced a multifunction photometric sensor and signal conditioning IC that includes AFE, ADC, LED driver, and timing core making it suitable for optical measurement applications, including gesture control and proximity sensing.

The ADUX1020 has an integrated 14-bit analog-to-digital converter (ADC) and a 20-bit burst accumulator that works in concert with a flexible light emitting diode (LED) driver. It is designed to modulate a LED and measure the corresponding optical return signal. The digital engine includes circuitry and control for data aggregation and proximity detection.

The data output and device configuration use a 1.8V I2C interface.

The control circuitry includes flexible LED pulse width and period generation combined with synchronous detection. This circuitry is complemented by a low noise, low power, and wide dynamic range configurable analog front end (AFE), clock generation, LED driver, and digital logic for position and smart sample mode (event driven x, y coordinates, relative z data). This complete AFE features ambient light rejection, avoiding corruption due to external interference.

One standard surface mount, broad angle or narrow-angle IR LED (depending upon application) is required. This LED mounts externally to the ADUX1020.

Packaged in a 2mm by 3mm, 8-lead LFCSP, the ADUX1020 is specified over an operating temperature range of −40°C to +85°C.

The chip is priced at $3.49 per unit in 1,000 unit quantities and is available in volume.