Description
The Si1120 is a low-power, reflectance-based proximity and ambient light sensor with advanced analog signal processing and analog PWM output. It includes an integrated differential photodiode, signal processor, and LED driver. Proximity sensing is based on the measurement of reflected light from an external, optically-isolated, strobed LED. A separate visible light photodiode is used for ambient light sensing. The standard package for the Si1120 is an 8-pin ODFN.

FEATUREs
◾ Typically 50 cm meter proximity
   range with single pulse
◾ Seven precision optical
   measurement modes:
   • 3 proximity ranges
   • 3 dc ambient ranges
   • 1 calibration mode
◾ Low-noise ambient cancelling
   circuit allows maximum
   sensitivity with 8–12 bit resolution
◾ ALS works in direct sunlight
   (100 klux)
◾ Minimum reflectance sensitivity
   <1 µW/cm2
◾ High EMI immunity without
   shielded packaging
◾ Power supply: 2.2–3.7 V
◾ Operating temperature range:
   –40 to +85 °C
◾ Typical 10 µA current
   consumption
◾ Programmable 400/50 mA LED
   constant current driver output
◾ Allows independent LED supply
   voltage
◾ Small outline 3 x 3 mm (ODFN)

APPLICATIONs
◾ Handsets
◾ Touchless switches
◾ Occupancy sensors
◾ Consumer electronics
◾ Notebooks/PCs
◾ Industrial automation
◾ Display backlighting control
◾ Photo-interrupter