VEasyLIT™ Ambient Light Sensor Board Assembly ® TM LXMG1800_LS P RODUCTION D ATASHEET • DESCRIPTION The board comes preprogrammed to drive the minimum inverter lamp brightness at complete darkness and full brightness when about 120 lux strikes the sensor. However the gain that determines this range is user adjustable both up or down by adding or removing solder bridge(s) to short jumpers J1 to J3 on the board. There are eight gain settings possible to tailor the sensor board to match a wide variety of lighting configurations. In addition connecting an external 500k rheostat to the inverter’s BRITE input pin will override the sensor output allowing further dimming. This rheostat (or a selected fixed resistor) could also be used to shift the sensor’s range down thus trimming the gain. The small size of the sensor board permits mounting it in the typically narrow space in the housing surrounding the LCD display. The length of the included wire harness (about 16”) allows flexible mounting of the sensor with respect to the inverter mounting location. • Save Energy By Automatically Adjusting Display Brightness to Meet Ambient Light Conditions • Uses Microsemi’s LX1974 Ambient Light Detector • Plug-in Automatic Dimming • Rated From -30°C to 80°C • Size 31mm x 9.5mm x 2.5mm • Easy Flush Mounting Against Display Bezel • Includes 16” Leads For Flexible Mounting in System • User Programmable Gain Settings • Compatible With Microsemi’s Single Lamp Inverters: LXMG1811-05-6xS LXMG1813-12-6xS WWW . Microsemi .C OM The LXMG1800_LS Ambient Light Sensor Board Assembly provides a ‘plugn-play’ automatic lamp dimming solution. It is designed particularly to mate with Microsemi’s LXMG1811-05-6xS (5V input) and LXMG1813-12-6xS (8.4V to 16V) single lamp CCFL inverters. Using the included wire harness and connector the LXMG1800_LS will plug into connector CN2 of the CCFL inverter and provide an automatic dimming solution based on ambient lighting conditions. This saves the time and effort needed to properly integrate this feature with an inverter. The board is designed to sense light through a hole in the bottom of the board assembly so it can be easily flush mounted against the back of the display housing. Ambient light can then be directed to the sensor through a small hole in the display bezel, a panel mounted light pipe, or transparent or translucent opening in the display housing. KEY FEATURES APPLICATIONS • Single Lamp CCFL LCD Displays • Portable Instrumentation Displays • Medical Instrument Displays IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com PRODUCT HIGHLIGHT 1 2 3 VEASYLIT™ LXMG1800_LS AMBIENT LIGHT SENSOR BOARD ASSEMBLY W LXMG1800_LS LXMG1811-05-6XS (5V) OR LXMG1813-12-6XS (8.4V TO 16V) ORDER INFORMATION RoHS Compliant Matching Microsemi Inverters LXMG1811-05-61S or LXMG1811-05-62S LXMG1813-12-61S or LXMG1813-12-62S LXMG1800_LS Copyright © 2008 Rev. 1.0, 2008-12-12 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 800-877-6458, 714-898-8121, Fax: 714-893-2570 Page 1 VEasyLIT™ Ambient Light Sensor Board Assembly ® TM LXMG1800_LS P RODUCTION D ATASHEET ABSOLUTE MAXIMUM RATINGS WWW . Microsemi .C OM Input Signal Voltage (ALS_VCC) ............................................................................................................................ -0.3V to 6V Output Voltage (ALS_OUT) ................................................................................................................................. -0.3V to 5.5V Ambient Operating Temperature, zero airflow ....................................................................................................-30°C to 80°C Storage Temperature Range ..............................................................................................................................-40°C to 85°C Exceeding these ratings could cause damage to the device. All voltages are with respect to Ground. Currents are positive into, negative out of specified terminal. ELECTRICAL CHARACTERISTICS Unless otherwise specified, the following specifications apply over the operating ambient temperature of 00C < Temp < 600C, and the following test conditions: ALS_VCC = 5V; J1 = Short, J2, J3 = OPEN (Factory Setting) Parameter Symbol Test Conditions / Comment LXMG1800_LS Min Typ Max Units ALS_OUT λPR Peak Spectral Response Input irradiance which produces maximum ALS_OUT voltage Input irradiance which produces maximum ALS_OUT voltage Input irradiance which produces maximum ALS_OUT voltage Input irradiance which produces maximum ALS_OUT voltage Input irradiance which produces maximum ALS_OUT voltage Maximum output voltage produced at ALS_OUT Minimum voltage produced at ALS_OUT 520 nm 2 EV0 J1, J2, J3 = OPEN 4.4 5.8 7.3 µW/cm EV1 J1 = Short, J2, J3 = OPEN (Factory Setting) 13.2 17.5 22 µW/cm 2 EV2 J2 = Short, J1, J3 = OPEN 26.3 35 43.8 µW/cm 2 EV3 J3 = Short, J1, J2 = OPEN 49.3 65.7 82 µW/cm 2 EV4 J1, J2, J3 = Short 78.8 105 131.4 µW/cm 2 2.1 2.8 V 0.6 0.8 V VBRITE_D VBRITE_D ALS_VCC = 4.5V to 5.5V Load = 499K; 120 lux ALS_VCC = 4.5V to 5.5V Load = 499K; 0 lux Note: The input irradiance (EV) is supplied from a white light-emitting diode (LED) optical source adjusted to impose the specified EV at a peak λ = 550nm. (For further details regarding irradiance vs. lux, see the LX1974 datasheet at: http://www.microsemi.com ) FUNCTIONAL PIN DESCRIPTION Name Pin # Description CN1 CN1-1 ALS_VCC Main Input Power Supply (Supplied through the inverter board ) 4.5V to 5.5V CN1-2 ALS_OUT Light sensor board output supplied to inverter for brightness control CN1-3 ALS_GND Light sensor board ground connected to inverter ground J1 J2 J3 Gain Factor OPEN OPEN OPEN 3.01 Highest Gain SHORT OPEN OPEN 1.00 Nominal Factory Setting OPEN SHORT OPEN 0.50 SHORT SHORT OPEN 0.38 OPEN OPEN SHORT 0.25 SHORT OPEN SHORT 0.21 OPEN SHORT SHORT 0.18 SHORT SHORT SHORT 0.16 Copyright © 2008 Rev. 1.0, 2008-12-12 LXMG1800_LS JUMPER GAIN SETTINGS Description Lowest Gain Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 800-877-6458, 714-898-8121, Fax: 714-893-2570 Page 2 VEasyLIT™ Ambient Light Sensor Board Assembly ® TM LXMG1800_LS P RODUCTION D ATASHEET LXMG1800_LS SCHEMATIC WWW . Microsemi .C OM VDD LX1974 VSS ALS_VCC ALS_OUT ALS_GND J1 J2 J3 MECHANICAL DRAWING 1.25mm x4 31.00mm 1.0mm hole x 4 VCC 14.25mm MICROSEMI 1.00mm ± 0.1 9.50mm 3 J1 J2 J3 Green 2 GND 4.75mm Orange 1 OUT Cable length is approximately 40cm (16") Black 1.25mm x4 CN1 Label wrapped around wire about 50mm from CN1 2.50mm MAX Light Sensor Aperture PCB Tolerances ± 0.2mm unless otherwise stated Total Assembly Weight: (2g) typ. APPLICATION INFORMATION Mounting Suggestions: The sensor module may be mounted using one of three methods: 1. Use thin double-sided sticky tape with a hole punched in the tape to allow light to enter at the location of the light sensor, and then mounting the sensor against the back surface of the front panel. 2. Two small mounting screws on either end utilizing the half moon mounting holes; these half holes have a diameter of 2.5mm. 3. The four small 1mm holes in each corner could be hot melted down to small tabs molded into a plastic housing. Light Aperture: Generally the sensor should be mounted behind the LCD bezel frame in the same plane as the display. A small hole in the bezel or translucent frosted light opening that allows light to strike the sensor will suffice. Using only a hole may not be cosmetically attractive and could become plugged with dust or other contaminates. One option is to use a panel mounted light pipe to conduct the light to the surface of the sensor PCB. Further information on optical design can be found on our brief application note AN-32 ‘Optical Design of Ambient Light Sensor’ which can be found at: http://www.microsemi.com/micnotes/1404.pdf Copyright © 2008 Rev. 1.0, 2008-12-12 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 800-877-6458, 714-898-8121, Fax: 714-893-2570 Page 3 LXMG1800_LS Adjusting the light gain, using jumpers J1 to J3: The LXMG1800_LS comes from the factory preset with a solder bridge across jumper J1, as described in Jumper Gain Setting Table on page two. Light sensitivity will be reduced further by creating a solder bridge(s) across jumpers J2 or J3 or any combination. Reducing light sensitivity means that it will take a brighter light striking the sensor to signal the inverter to drive the panel to full brightness. Likewise if greater sensitivity is required (less light striking sensor to reach maximum lamp brightness) then the solder bridge on jumper J1 can be removed, using solder wick or vacuum removal tool. Which gain setting to use depends on the desired dimming range, ambient light conditions of the application and any loss in the light pipe or panel bezel used to supply light to the sensor assembly. The gain can also be trimmed downward by adding and adjusting a 500k rheostat, or selected fixed resistor to the inverter’s BRITE input pin to ground. VEasyLIT™ TM LXMG1800_LS Ambient Light Sensor Board Assembly ® P RODUCTION D ATASHEET NOTES WWW . Microsemi .C OM LXMG1800_LS PRODUCTION DATA – Information contained in this document is proprietary to Microsemi and is current as of publication date. This document may not be modified in any way without the express written consent of Microsemi. Product processing does not necessarily include testing of all parameters. Microsemi reserves the right to change the configuration and performance of the product and to discontinue product at any time. Copyright © 2008 Rev. 1.0, 2008-12-12 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 800-877-6458, 714-898-8121, Fax: 714-893-2570 Page 4