Digital Ambient Light and Proximity Sensor

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APDS-9901 provides digital ambient light and proximity sensing (ALS), IR LED and a complete proximity detection system in a single 8 pin package. The proximity function offers plug and play detection to 100 mm (without front glass) thus eliminating the need for factory calibration of the end equipment or sub-assembly. The proximity detection feature operates well from bright sunlight to dark rooms. The wide dynamic range also allows for operation in short distance detection behind dark glass such as a cell phone. In addition, an internal state machine provides the ability to put the device into a low power mode in between ALS and proximity measurements providing very low average power consumption. The ALS provides a photopic response to light intensity in very low light condition or behind a dark faceplate.

APDS-9901 digital ambient light and proximity sensor is particularly useful for display management with the purpose of extending battery life and providing optimum viewing in diverse lighting conditions. Display panel and keyboard backlighting can account for up to 30 to 40 percent of total platform power. The ALS features are ideal for use in notebook PCs, LCD monitors, flat-panel televisions, and cell phones.

The proximity function is targeted specifically towards near field proximity applications. In cell phones, the proximity detection can detect when the user positions the phone close to their ear. The device is fast enough to provide proximity information at a high repetition rate needed when answering a phone call. This provides both improved “green” power saving capability and the added security to lock the computer when the user is not present. The addition of the micro-optics lenses within the module, provide highly efficient transmission and reception of infrared energy which lowers overall power dissipation.


ALS, IR LED and Proximity Detector in an Optical Module
  • Ambient Light Sensing (ALS)
– Approximates Human Eye Response
– Programmable Interrupt Function with Upper and Lower Threshold
– Up to 16-Bit Resolution
– High Sensitivity Operates Behind Darkened Glass
– Up to 1,000,000:1 Dynamic Range
  • Proximity Detection
– Fully Calibrated to 100 mm Detection
– Integrated IR LED and Synchronous LED Driver
– Eliminates “Factory Calibration” of Prox
– Covers a 2000:1 Dynamic Range
  • Programmable Wait Timer
– Wait State Power – 70 µA Typical
– Programmable from 2.72 ms to > 6 Sec
  • I2C Interface Compatible
– Up to 400 kHz (I2C Fast-Mode)
– Dedicated Interrupt Pin
– I2C VBUS = VDD Interface
  • Sleep Mode Power - 2.5 µA Typical
  • Small Package L3.94 x W2.36 x H1.35 mm


  • Cell Phone Backlight Dimming
  • Cell Phone Touch-screen Disable
  • Notebook/Monitor Security
  • Automatic Speakerphone Enable
  • Automatic Menu Pop-up
  • Digital Camera Eye Sensor

Lifecycle Status


Substance Compliance

  • RoHS6
    Fully Compliant
Specification Value
Lifecycle Active
Distrib. Inventory Yes
ALS Output Digital I2C
PS Output Digital I2C
Supply Voltage (V) 2.5 – 3.6