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LX1973 TM (R) Automotive Light Sensor PRODUCTION DATA SHEET DESCRIPTION KEY FEATURES Human Eye Spectral Response 25C Dark Current < 0.005 lux 5 Decades Compressed Output 10% Accuracy Over Temperature Scalable Output Voltage No Optical Filters Needed The LX1973 is a wide dynamic range light sensor with a very low dark current that is optimized for sensing low level light signals that typically occur under dark or darkening outdoor ambient lighting. The LX1973 has been optimized for automotive systems such as headlamp brightness control or rear view mirror contrast control. Its radical (fractional exponent) response when interfaced with an 8 bit DAC can detect levels down to 0.001 lux or levels as high as 500 lux. The spectral response of the integrated light sensor closely emulates the human eye so it ignores light such as infrared which emits energy but doesn't aid vision. This eliminates the need for an Infrared filter required with competitor's light sensors. The LX1973 internal circuitry consists of a diode array that provides a nearly perfect photopic light wavelength response curve. The sensor output feeds into a wide dynamic range compression amplifier that provides accurate resolution over five decades of ambient light. The integrated dark current cancellation circuit facilitates accurate sensing of light below 0.01 lux. The current source output of the LX1973 can be gain scaled using one external resistor. The LX1973 is internally trimmed to an initial accuracy of 5% at room temperature and a light level of 10lux. Accuracy of 10% is maintained over the full temperature range (-40 to +85C). WWW .Microsemi .C OM APPLICATIONS Auto Headlamp Control Auto Mirror Contrast Control IMPORTANT: For the most current data, consult MICROSEMI's website: http://www.microsemi.com Protected by US Patent: 6,787,757; Patents Pending PRODUCT HIGHLIGHT LX1973 Response 5V Output (in Volts) 4.0000 3.0000 2.0000 1.0000 0.0000 0.001 NC LX1973 Part VOUT 10k 0.01 0.1 1 10 100 Ambient Light (in lux) LX1973 LX1973 PACKAGE ORDER INFO TA (C) -40 to 85 DU Plastic MSOP 8-pin RoHS Compliant / Pb-free LX1973IDU Note: Available in Tape & Reel. Append the letters "TR" to the part number. (i.e. LX1973IDU-TR) Copyright (c) 2004 Rev. 1.0 2006-01-04 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 1 LX1973 TM (R) Automotive Light Sensor PRODUCTION DATA SHEET ABSOLUTE MAXIMUM RATINGS VDD ................................................................................................................. -0.3 to 6 VDC SNK/SRC (Output Compliance Voltage)........................................... -0.3 to VDD + 0.3VDC SNK/SRC (Maximum Output Current)................................................... Internally Limited Maximum Operating Junction Temperature ..............................................................150C Operating Temperature Range ........................................................................ -40 to +85C Storage Temperature Range.............................................................................-55 to 125C Peak Package Solder Reflow Temp. (40 seconds maximum exposure) .......... 260 (+0, -5) Notes: 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. Solder reflow to follow: IPC/JEDEC J-STD-020B 7/02 Pb-SN Small Body Profile PACKAGE PIN OUT WWW .Microsemi .C OM VDD NC NC OUT 1 2 3 4 8 7 6 5 VSS NC NC NC DU PACKAGE (Top View) 8 1 1973 xxxx 7 6 2 3 4 THERMAL DATA 5 PACKAGE MARKING (Bottom View) DU Plastic MSOP 8-Pin 39C/W 206C/W xxxx - Denotes Date Code / Lot information THERMAL RESISTANCE-JUNCTION TO CASE, JC RoHS / Pb-free 100% matte Tin Lead Finish THERMAL RESISTANCE-JUNCTION TO AMBIENT, JA Junction Temperature Calculation: TJ = TA + (PD x JA). The JA numbers are guidelines for the thermal performance of the device/pc-board system. All of the above assume no ambient airflow. FUNCTIONAL PIN DESCRIPTION Name VDD VSS OUT VDD Input Supply Voltage Ground Reference for Power and Signal Output Output Current Input Supply Voltage PACKAGE PHOTO Description SIMPLIFIED BLOCK DIAGRAM VDD Photopic Sensor with Dark Current Cancellation Pre Amplifier Compression Amplifier OUT PACKAGE DATA PACKAGE DATA GND In Package Trim NC Figure 1 - Simplified Block Diagram Copyright (c) 2004 Rev. 1.0 2006-01-04 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 2 LX1973 TM (R) Automotive Light Sensor PRODUCTION DATA SHEET Unless otherwise specified, the following specifications apply over the operating ambient temperature -40C TA otherwise noted and the following test conditions: See Note 1, VDD =5V, ROUT = 10k. Parameter Operational Voltage Supply Current Power Supply Rejection Ratio Peak Spectral Response Infrared Response Light to Current Gain Output Current Output Current Output Current Saturation Current Dark Current (Equivalent lux) Dynamic Response Time Radiant Sensitive Area Symbol VDD IDD PSRR PR Test Conditions EV = 1 lux VRIPPLE = 100mVP-P, f = 10kHz; COUT = 0.1F EV(550nm) = EV(800nm) = 146nW/cm, Note 3 See application section for equation EV = 0.01 lux @ 25C EV = 1 lux, Note 2 EV = 100 lux, Note 2 EV = 0 lux, TA = 20C, Note 4 EV = 0 lux, TA = 50C, Note 4 10% settling error (146 nW/cm to 1.46 nW/cm step response) ELECTRICAL CHARACTERISTICS 85C except where WWW .Microsemi .C OM Min 4.5 30 -5 34 108 342 650 LX1973 Typ 0.2 35 550 1 38 120 380 450 2100 1.5 0.20 Max 5.5 0.25 Units V mA dB nm % A A A A Lux sec mm 2 IDD ( ) IDD ( PR ) GL IOUT(0.01) IOUT(1.0) IOUT(100) ISAT IOUT (DARK) TDR 5 42 132 418 900 10000 3 Notes: 1. The input irradiance (EV) is supplied from a white light-emitting diode (LED) optical source adjusted to impose the specified EV at = 550nm. 2. See Figure 1. 3. See Figure 2. 4. Dark Current equivalent lux at 0 lux: I EL = OUT / 146 x10 -9 6163A TEST CIRCUITS 4 VDD LX1973 VDD VDD LX1973 VDD White LED NC OUT Part GND VOUT 10k White LED NC OUT Part GND VOUT 800nm ELECTRICALS ELECTRICALS 10k Figure 3 - IR Sensitivity Measurement Circuit Figure 2 - Operational Voltage Measurement Circuit Copyright (c) 2004 Rev. 1.0 2006-01-04 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 3 LX1973 TM (R) Automotive Light Sensor PRODUCTION DATA SHEET APPLICATION CIRCUITS WWW .Microsemi .C OM 5V 5V Part LX1973 10K 1F LX1800 To P SCL SCD GND ADR VDD REF AIN Part 2.5V AOUT DAC/ADC BRT HEADLAMP CONTROLLER LAMP Figure 4 - Typical Application APPLICATION CIRCUITS GENERAL DESCRIPTION The LX1973 produces an output current that is sensitive to the level of ambient light that falls onto the photosensitive area of the IC package. The sensitivity is amplified and compressed to provide ratio metric accuracy across several decades. The sensitivity function is: I OUT P = () ( 6163A x PDARK + PAMBIENT 0.25 W 2 cm ) [ ]0.25 APPLICATIONS APPLICATIONS where PDARK is the dark current equivalent power and PAMBIENT is the ambient illumination both expressed in W/cm at a 555nm wavelength. PDARK is approximately 7pW/cm at 25C. Copyright (c) 2004 Rev. 1.0 2006-01-04 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 4 LX1973 TM (R) Automotive Light Sensor PRODUCTION DATA SHEET SENSITIVITY DARK CURRENT VS TEMP WWW .Microsemi .C OM Output Current (uA) 500 400 300 200 100 0 0.001 0.01 0.1 1 10 100 1000 Ambient Light (lux) Dark Equiv Lux (uLux) 600 10000 1000 100 10 1 0 10 20 30 40 50 60 70 80 85 Temperature (C) Limit Typical RESPONSE VS WAVELENGTH 16 14 12 10 8 6 4 2 0 0 IOUT STEP RESPONSE LX1973 Range Amplitude (W/cm ) 2 0.5 Time (Seconds) 1 Load = 3.8k and 1F Photo Step = Direct Light Input of 14.6W/cm2 MAXIMUM OUTPUT VOLTAGE Maximum Output Votage (V) 6 5 4 3 2 1 0 1 10 100 1000 Output Current (uA) VDD = 5.5V VDD = 5V CHARTS CHARTS Copyright (c) 2004 Rev. 1.0 2006-01-04 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 5 LX1973 TM (R) Automotive Light Sensor PRODUCTION DATA SHEET PACKAGE DIMENSIONS WWW .Microsemi .C OM DU 8-Pin Miniature Shrink Outline Package (MSOP) D Top View E1 S e E A A1 b L Side Views c L1 Dim A A1 b c D e E E1 L L1 S MILLIMETERS MIN MAX - 1.10 0.05 0.15 0.26 0.41 0.13 0.23 2.90 3.10 0.65 BSC 4.75 5.05 2.90 3.10 0.41 0.71 0.95 BSC 0.525 BSC 3 INCHES MIN MAX - 0.043 0.002 0.006 0.010 0.016 0.005 0.009 0.114 0.122 0.025 BSC 0.187 0.198 0.114 0.122 0.016 0.028 0.037 BSC 0.021 BSC 3 Active Area Required Minimum Light footprint Bonding / Wafer area Active Area MILLIMETERS Dim A a B C P1 1.22 0.85 0.60 0.60 2.5 INCHES 0.048 0.033 0.024 0.024 0.98 C B C L Examination of Active Area Recommended light footprint pattern P1 (recommended) Note: P1 represents a possible light footprint and its dimensions are not subject to strict tolerances. Only the active area of the device is required to be covered with light. This larger footprint is designed to ensure coverage of the device's active area. MECHANICALS MECHANICALS Copyright (c) 2004 Rev. 1.0 2006-01-04 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 6 LX1973 TM (R) Automotive Light Sensor PRODUCTION DATA SHEET NOTES WWW .Microsemi .C OM NOTES NOTES 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 (c) 2004 Rev. 1.0 2006-01-04 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 7 |
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