TSL2550 Ambient Light Sensor with SMBus Interface The TSL2550 is a digital-output light sensor with a two-wire, General Description SMBus serial interface. It combines two photodiodes and a companding analog-to-digital converter (ADC) on a single CMOS integrated circuit to provide light measurements over an effective 12-bit dynamic range with a response similar to that of the human eye. The TSL2550 is designed for use with broad wavelength light sources. One of the photodiodes (channel 0) is sensitive to visible and infrared light, while the second photodiode (channel 1) is sensitive primarily to infrared light. An integrating ADC converts the photodiode currents to channel 0 and channel 1 digital outputs. Channel 1 digital output is used to compensate for the effect of the infrared component of ambient light on channel 0 digital output. The ADC digital outputs of the two channels are used to obtain a value that approximates the human eye response in the commonly used unit of Lux. This device is intended primarily for use in applications in which measurement of ambient light is used to control display backlighting such as laptop computers, PDAs, camcorders, and GPS systems. Other applications include contrast control in LED signs and displays, camera exposure control, lighting controls, etc. The integrating conversion technique used by the TSL2550 effectively eliminates the effect of flicker from AC-powered lamps, increasing the stability of the measurement. Ordering Information and Content Guide appear at end of datasheet. Key Benefits & Features The benefits and features of TSL2550, Ambient Light Sensor with SMBus Interface are listed below: Figure 1: Added Value of Using TSL2550 Benefits Features Enables Operation in IR Light Environments Patented Dual-Diode Architecture Digital Interface Is Less Susceptible to Noise Two-Wire SMBus Digital Interface Enabling Low Active and Power-Down Modes 1mW (typ) Active Power Mode Reduces Average Power Consumption Reduces Board Space Requirements while Available in 2.6mm x 3.8mm TMB or 5mm x 6.2mm Simplifying Designs SOIC (D) Packages ams Datasheet Page 1 v1-00 2016-May-20 Document FeedbackT S L2 550 G e ne ral D e sc r i ption Converts Light Intensity to Digital Signal Infrared Compensation to Approximate Human Eye Response Companding A/D for Wide Dynamic Range Rejects 50 Hz/60 Hz Lighting Ripple Single Supply Operation (2.7 V to 5.5 V) Power Down Mode Low-Profile Surface-Mount Packages Functional Block Diagram The functional blocks of this device are shown below: Figure 2: TSL2550 Block Diagram Integrating Channel 0 A/D Converter Photodiode Channel 1 Photodiode V = 2.7 V to 5.5 V DD Control Logic Output Registers SMBCLK Two-Wire Serial Interface SMBData Page 2 ams Datasheet Document Feedback v1-00 2016-May-20