ams’ digital ambient light sensor features an integrated on-chip photopic filter

The TSL2540 from ams was developed as the 4th generation ambient light sensor (ALS) and includes an integrated on-chip photopic filter which provides near photopic responsiveness for operation behind the inked glass of a touch panel display. The TSL2540 is a highly sensitive light-to-digital converter that transforms light intensity into a digital signal output through a fast-mode direct I²C digital interface. This digital output can be input to a microprocessor where illuminance (ambient light level) in lux is derived using an empirical formula to provide accurate metering of light intensity that approximate the sensitivity of the human-eyes response, regardless of the light source (sunlight, incandescent, halogen, fluorescent, CFL, LED, etc.). The 1M-to-1 dynamic range of the device, coupled with the integrated silicon photopic filter, makes this ALS suitable for industrial designs that hide behind dark inked glass for aesthetic purposes.

The TSL2540 is part of the ALS product offering and features very high sensitivity with low power consumption in a small 2 mm x 2 mm x 0.5 mm optical QFN package making it ideal for space-constrained designs. The TSL2540 is capable of operation from mLux to 50k lux environments, allowing it to operate in small and deeply buried sub-system applications.


  • Integrated on-chip photopic filter
  • High sensitivity down to mLux levels
  • 0.18 µm process technology with 1.8 V I²C
  • 1M:1 dynamic range
  • Automatic AUTO zero/dark count control
  • Area efficient 2.0 mm x 2.0 mm x 0.5 mm QFN package
  • Ambient light sensing
  • Display backlight control


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I am a highly skilled and motivated individual with a Master's degree in Computer Science. I have extensive experience in technical writing and a deep understanding of SEO practices.

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