Texas Instruments OPT3005 Ambient Light Sensor (ALS)

Texas Instruments OPT3005 Ambient Light Sensor (ALS) is a single-chip lux meter measuring the intensity of light as visible by the human eye. The extreme IR rejection and precision spectral response of the OPT3005 enable it to accurately meter the intensity of light as seen by the human eye regardless of the light source and any stray light from 850nm or 940nm active illumination. The extreme IR rejection helps to maintain high accuracy when industrial design calls for mounting the sensor under the dark glass, especially with active 850nm or 940nm NIR illumination. These systems typically have a lot of NIR stray reflections from the cover glass, which can affect the light sensor measurement. The precision optical filtering of OPT3005 is verified for resilience to such stray NIR reflection and truly measures the ambient light as perceived by the human eye.

The Texas Instruments OPT3005 is designed for systems that create light-based experiences for humans. It is a preferred replacement for photoresistors, photodiodes, or other ambient light sensors with less human eye matching and IR rejection. Measurements can be made from 20mlux up to 166klux without manually selecting full-scale ranges using the built-in, full-scale setting feature. This capability allows light measurement over a 23-bit effective dynamic range.


  • Precision optical filtering to match the human eye
    • Rejects 99.99+% (4+ orders) of Near Infrared (NIR) light over a large angle of incidence
  • Built-in automatic full-scale light range selection logic, which switches measurement range based on input light condition with the excellent gain matching between ranges
  • Measurements (20mlux to 167klux)
  • 12 Binary-weighted full-scale range settings
    • < 0.2% (typical) matching between ranges
  • 23-Bit Effective dynamic range with automatic gain ranging
  • 1.8µA (Typical) low operating current
  • –40°C to +85°C operating temperature range
  • 1.6V to 3.6V wide power-supply range
  • 5.5V tolerant I/O
  • Flexible interrupt system
  • Small-form factor
    • 2.1mm × 1.9mm × 0.6mm for SOT-5X3 package


  • IP network cameras
  • Security camera
  • Video doorbell
  • Applications requiring light sensing along with 850nm or 940nm active NIR illumination

Functional Block Diagram

Block Diagram - Texas Instruments OPT3005 Ambient Light Sensor (ALS)
Published: 2023-02-23 | Updated: 2023-03-03