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TSL2561 Ambient Light Sensor

Light-to-digital converter with I2C interface


  • Patented dual-diode architecture
  • 1M:1 dynamic range
  • Programmable interrupt function
  • I²C digital interface
  • Available in 1.25mm x 1.75mm chip-scale or 2.6mm x 3.8mm TMB or 2mm x 2mm Dual Flat no-lead (FN) packages


  • Enables operation in IR light environments
  • Enables dark room to high lux sunlight operation
  • Reduces microprocessor interrupt overhead
  • Digital interface is less susceptible to noise
  • Reduces board space requirements while simplifying designs

Product parameters

Supply Voltage [V] 2.7 - 3.6
Interface I2C - VDD
Programmable Gain, integration time, interrupt
Max. Lux 40000
Temperature Range [°C] -30 to 70
Packages (6-Pin) CL, FN, CS, T
Remark Not recommended for new designs. Please see TSL2572x device family.

General Description

The TSL2561 is a light-to-digital converter that transforms light intensity to a digital signal output capable of an I2C interface. Each device combines one broadband photodiode (visible plus infrared) and one infrared-responding photodiode on a single CMOS integrated circuit capable of providing a near photopic response over an effective 20-bit dynamic range (16-bit resolution). Two integrating ADCs convert the photodiode currents to a digital output that represents the irradiance measured on each channel. This digital output can be input to a microprocessor where illuminance (ambient light level) in lux is derived using an empirical formula to approximate the human eye response. The TSL2561 device supports a traditional level style interrupt that remains asserted until the firmware clears it. Not Recommended for New Designs! ams does not recommend using the FN PACKAGE VARIANTS of this product for new designs. Please contact your local sales representative for further information regarding available or planned replacement options.

This product suits for the following applications:

  • Display backlight control
  • Keyboard illumination control
  • Solid state and general lighting control
  • Printer paper detection


Title Category Headline Buy
TSL256xEvalKit Application Board Evaluation Kit for TSL256x

Technical Documents

Name Type Description Version Language
AmbientLightSensors_AN000530_1-00.pdf Application Note TSL258x: Accurate ADC Readings after Enable (DN42) 1-00 English
AmbientLightSensors_AN000104_1-00.pdf Application Note Optical Window Design (DN13B) 1-00 English
AmbientLightSensors_AN000173_2-00.pdf Application Note Custom Lux Equation (DN28) 2-00 English
AmbientLightSensors_AN000172_2-00.pdf Application Note Ambient Light Sensing (DN26) 2-00 English
AmbientLightSensors_AN000171_2-00.pdf Application Note Auto-gain Algorithm (DN39) 2-00 English
AmbientLightSensors_AN000170_2-00.pdf Application Note Using the Lux Equation (DN29A) 2-00 English
AmbientLightSensors_AN000169_2-00.pdf Application Note Sensitivity to Temperature (DN24) 2-00 English
AmbientLightSensors_AN000168_2-00.pdf Application Note Sensitivity to Wavelength (DN23) 2-00 English
AmbientLightSensors_AN000167_2-00.pdf Application Note Radiometric and Photometric Measurements (DN21) 2-00 English
AmbientLightSensors_AN000268_1-00.pdf Application Note Improving Color Sensor Lux Accuracy 1-00 English
LightSensors_AN000519_1-00.pdf Application Note Colorimetry Tutorial (DN 20) 1-00 English
TSL2561_BD000153_1-00.png Block Diagram TSL2561 Block Diagram 1-00 English
TSL2561_DS000110_3-00.pdf Datasheet Document version 1-01 3-00 English
TSL2561CL_EN000126_1-00.pdf EoL Notification TSL2561CL (issued 2017-Jan) 1-00 English
TSL2561_PD000348_1-00.png Other Product Document TSL256xEvalKit Image 1-00 English

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