ams Sensor-Driven Lighting


Increase energy savings with a Cognitive Lighting System for Daylight Harvesting and Color Tuning

Features of Sensor-Driven Lighting

Increase Energy Savings

  • Digital Ambient Light Sensor or Digital Color Sensor + Precision LED Driver =  more than 50% energy savings

Autonomous Control

  • Digital ambient light sensor will automatically control the electrical lighting contribution to balance with natural light

Wired/wireless interface


Adapts lighting color temperature to human needs

  • Ideal for factories, offices, hotel rooms, residences, hospitals

Healthier natural lighting

  • Better support circadian rhythm
  • Lower blue content (460nm) for melatonin management

Low power consumption


How Does Daylight Harvesting Work?

Daylight Harvesting Sensor Fixtures

Energy Savings with Daylight Harvesting

ALS sensor detects high and low daylight contribution and signals dimming/increasing illumination to light fixture.

When lights dim using Daylight Harvesting you are saving over 30% of energy

Energy Savings with Daylight Harvesting

System Overview

ams Devices TSL4531 TCS3472 aLC AS3691-6 Benefits
Not a photo Diode RGB Sensor Lighting Controller Code Precision LED Driver System Level Solutions
Daylight Harvesting   >50% Energy Savings Auto Lumen Maintenance
Color Tunable   Adjust Color Temp in Lamp Color Maintenance

Target Applications

Outdoor/Street Lighting

  • Roads/Pathways
  • Transportation Stations
  • Parking Lots

Commercial Lighting

  • Office Buildings
  • Hotels
  • Restaurants
  • Schools

Industrial Lighting

  • Warehouses
  • Factories
  • Shipping Yards

Specialty/Retail Lighting

  • Decorative Lighting
  • Mood Lighting
  • Point-of-Sales

TSL4531 - Digital Ambient Light Sensor

A digital daylight sensor is built into the luminaire that automatically responds to its environment is a perfect solution for reducing energy consumption and costs. The TSL4531 combines photopic, human-like sensitivity with wide dynamic range which enables a new generation of lighting controls to be built directly into replacement lamps and luminaires to shift more of the interior lighting burden seamless onto available daylight.

Main Features:

  • Photopic response that mimics the human eye in color sensitivity, while excluding IR and ultraviolet energy
  • Wide dynamic range with high lux capability up to 220K – twice the brightness of sunlight
  • Digital I2C interface that readily connects to a microcontroller and additional wired or wireless networking
  • Affordable enough to be built into LED replacement lamps and lighting instruments
  • Low power, using only 110 uA in active mode and 2.2uA in power down state
  • Small size at 2mm square, its small enough to fit into almost any LED luminaire.
Product Operating Voltage Sensitivity I2C Bus Flexible timing Package
TSL4531 2.6-3.6 Direct LUX Output Vdd Automatic Gain Control CL

Supporting Tools and Information


ams Lighting Controller

The ams lighting controller (aLC) connects the digital optical sensors to the precision LED drivers to provide a complete lighting solution that can be easily commissioned and deployed.

The aLC (ams Lighting Controller) is code that runs on a Microchip PIC24F:

  • Interfaces the TSL4531 or TCS3472 on one side of the PIC24 processor
  • Connects the PIC24F to the LED drivers AS3691/6 on the other side
  • Process the information from the sensors for daylight processing or color temperature processing to generate adequate light
  • Commissions the lamp for adequate operation

Code can be run as a custom process with the ams Lighting API - please contact ams directly for licensing the source code at

Supporting Tools and Information


AS3696 - 4 Channel Precision LED Driver With external FETs

The AS3696 is a 4 channels precision LED controller with PWM inputs or internal PWM generator for driving external FETs in precise lighting applications. Build in safety features include thermal shutdown as well as open and short LED detection.


  • Current accuracy +/- 1%
  • Channel to channel matching +/- 1%
  • Open and shorts detection
  • Digital or analog PWM input
  • High output voltage compliance, limited by external FETs
  • Integrated over-temperature protection
Product Operating Voltage Sensitivity I2C Bus Flexible timing Package
AS3696 2.6-3.6 Direct LUX Output Vdd Automatic Gain Control CL

Supporting Tools and Information


AS3691 - Quad Channel Precision LED Driver With Integrated FETs

The AS3691 features four high precision current sources for driving up to four LED strings. Each of the four currents sources can be controlled independently by PWM inputs. The full scale current value is set by external resistors.


  • Current Accuracy +/- 0.5%
  • 4 High precision 400ma constant current drivers
  • integrated FETs
  • Integrated 4 channel Dimming control
  • Adaptive supply regulation for maximum efficiency
  • High output voltage compliance 0.41V to 15V
  • Integrated over-temperature protection
Product Operating Voltage Sensitivity I2C Bus Flexible timing Package
AS3691 2.6-3.6 Direct LUX Output Vdd Automatic Gain Control CL

Supporting Tools and Information


TCS3472 - Digital Color Light Sensor

Enabling Color Adaption to Daylight Changes for Indoor Lighting

The TCS3472 device provides a digital return of red, green, blue (RGB), and clear light sensing values. An IR blocking filter, integrated on-chip and localized to the color sensing photodiodes, minimizes the IR spectral component of the incoming light and allows color measurements to be made accurately. The high sensitivity, wide dynamic range, and IR blocking filter makes the TCS3472 an ideal color sensor solution for use under varying lighting conditions and through attenuating materials.


  • Cost Savings with built-in IR filter to accurately measure visible light for color measurements
  • Color temperature adjustment can be used with daylight compensation to maintain the ambient lighting closer to a target color temperature
  • Feedback color sensors control adjustments to the luminaires
  • Excellent Accurate Readings with 4 analog to digital converts that read the red, green, blue & clear

Technical Specs:

  • Programmable interrupt function with user-defined upper and lower threshold setting
  • In-package trim provides an easy and accurate means to achieve system-to-system repeatability
  • 16-bit digital output with I2C at 400kHz
  • Programmable analog gain and integration time supporting 1,000,000 - to - 1 dynamic range
  • Low Power Wait State Operation, 65 uA Typical Current, Sleep Mode — 2.5 uA Typical Current
  • Wait Timer is Programmable from 2.4 ms to > 7 Seconds
Product Operating Voltage Clear Channel Array IR Filter Alternate Address Option Ambient Light Sensing Interface Package
TCS3472 2.7-3.3 Yes 4X4 No No Yes i2C FN  

Supporting Tools and Information


Featured Products:

AS8223 - FlexRay™ Active Star - ams' AS8223 is a monolithic FlexRay™ compliant Active Star device that manages communication traffic between the communication controller interface and four FlexRay branches.

AS5140 – Automotive Rotary Encoder IC - ams' AS5140H is a contactless magnetic rotary encoder for accurate angular measurement over a full turn of 360° and over an extended ambient temperature range of -40°C to 150°C.