Optical sensor combines ambient light and proximity sensors

January 04, 2012 // By Julien Happich
Maxim Integrated Products' MAX44000 is a digital ambient-light and infrared proximity sensor that detects light like a human eye. Designed using the company’s proprietary BiCMOS technology, this IC integrates three optical sensors, two ADCs, and digital functionality into a single package measuring only 2x2x0.6mm.

This integration saves valuable board space while delivering optical fusion and unparalleled light-sensing performance. The MAX44000 also consumes very low power: only 5µA when the ambient sensor is enabled, and only 7µA when both the proximity sensor and ambient light sensor are activated. This low-power usage significantly extends an application’s battery life. The MAX44000 is well suited for touch-screen applications, including smartphones, portable devices, industrial sensors, and presence detection. Once a sensed signal is received, it is run through a DC ambient, infrared (IR) rejection front-end circuit and sent to an ADC.

This process allows the MAX44000 to operate in the presence of large amounts of DC IR radiation. By using a single-pulse technique for pulsing the external IR LED, the sensor is immune to fixed-frequency external IR radiation. This immunity leads to more reliable sensor operation. Maxim’s BiCMOS technology enables the integration of the two photodiodes and an optical filter to reject UV and IR light. This allows the MAX44000 to replicate the optical response of the human eye in a variety of environments. The 6-pin UTDFN-Opto-EP part operates between -40 and +105°C

Get the data sheet at www.maxim-ic.com/MAX44000

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