LX1973B Automotive Light Sensor ® TM P RODUCTION D ATA S HEET KEY FEATURES DESCRIPTION Nearly Perfect Best Eye™ Human Eye Spectral Response Dark Current < 0.0005 Lux (@ 25°C) 5 Decades Compressed Output 10% Accuracy Over Temperature Scalable Output Voltage No Optical Filters Needed APPLICATIONS WWW . Microsemi .C OM The LX1973B internal circuitry consists of a diode array with Microsemi’s Best Eye™ processing 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 LX1973B can be gain scaled using one external resistor. The LX1973B is internally trimmed to an initial accuracy of 5% at room temperature and a light level of 10 Lux. Accuracy of 10% is maintained over the full temperature range (-40 to +85ºC). The LX1973B 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 LX1973B 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. Auto Headlamp Control Auto Mirror Contrast Control IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com Protected By US Patents: 6,787,757; Patents Pending PRODUCT HIGHLIGHT LX 1973B Response 5V 4 LX1973B Part Output (volts) 3 VOUT RLOAD 2 1 0 0.001 0.01 0 .1 1 10 100 LX1973B A m b ien t L ig h t (lu x ) PACKAGE ORDER INFO TA (°C) -40 to 85 PL Plastic MSOP Domed 8-Pin PR Plastic MSOP Domed 8-Pin Reverse Form RoHS Compliant / Pb-free, NiPdAu Finish RoHS Compliant / Pb-free, NiPdAu Finish LX1973BIPL LX1973BIPR Note: Available in Tape & Reel. Append the letters “TR” to the part number. (i.e. LX1973BIPLxxxxx-TR) Copyright © 2007 Rev. 1.3, 2008-01-11 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 1 LX1973B ® TM Automotive Light Sensor P RODUCTION D ATA S HEET ABSOLUTE MAXIMUM RATINGS PACKAGE PIN OUT PL PACKAGES (Top View) 973B YWWB Notes: 1. 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. VSS NC NC NC VDD NC NC OUT VSS NC NC NC VDD NC NC OUT WWW . Microsemi .C OM VDD ................................................................................................................. -0.3 to 6 VDC SNK/SRC (Output Compliance Voltage)........................................... -0.3 to VDD + 0.3VDC SNK/SRC (Maximum Output Current)................................................... Internally Limited Operating Temperature Range ........................................................................ -40 to +85°C Storage Temperature Range.......................................................................... -40 to +100°C RoHS / Pb-free Peak Package Solder Reflow Temperature (40 seconds maximum exposure)..................................................................240°C (+0, -5) PL PACKAGE MARKING (Bottom View) THERMAL DATA Plastic MSOP Domed 8-Pin Plastic MSOP Domed 8-Pin Reverse Form THERMAL RESISTANCE-JUNCTION TO CASE, θJC THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA 973B YWWB PL PR VSS NC NC NC 39°C/W 206°C/W PR PACKAGE MARKING (Top View) Junction Temperature Calculation: TJ = TA + (PD x θJA). The θJA numbers are guidelines for the thermal performance of the device / pc-board system. All of the above assume no ambient airflow. VSS NC NC NC VDD NC NC OUT FUNCTIONAL PIN DESCRIPTION Name Pin PR PACKAGES (Bottom View) Description VDD 1 Power Supply Voltage VSS 8 Ground Reference for Power and Signal Output OUT 4 Output Current VDD NC NC OUT NC – No Connection MSL3/240°C/168 Hours SIMPLIFIED BLOCK DIAGRAM PACKAGE VDD Pre Amplifier Compression Amplifier LX1973B Photopic Sensor with Dark Current Cancellation OUT GND LX1973B Figure 1 – Simplified Block Diagram LX1973BIPL Copyright © 2007 Rev. 1.3, 2008-01-11 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 LX1973BIPR Page 2 LX1973B Automotive Light Sensor ® TM P RODUCTION D ATA S HEET ELECTRICAL CHARACTERISTICS The following specifications apply over the operating ambient temperature -40°C ≤ TA following test conditions: See Note 1, VDD =5V, ROUT = 10k. Operational Voltage Supply Current Power Supply Rejection Ratio Peak Spectral Response Infrared Response Light to Current Gain Saturation Current Dynamic Response Time (to 10% Settling Error Point) ` Dome Top Package Output Current Output Current Output Current Output Current Dark Current (Equivalent Lux) Symbol 85°C except where otherwise noted and the Test Conditions VDD IDD PSRR λPR @ 1 Lux VRIPPLE = 100mVP-P, f = 10kHz; COUT = 0.1µF IDD (λ ) IDD (λ PR ) EV(white) = 100 Lux, EV(810nm) = 14.6µWatt/ cm², Note 3 LX1973B Units Min Typ Max 4.5 GL ISAT 5.5 0.27 V mA dB nm 30 0.22 35 580 -5 1 5 % 0.63 0.2 1.25 0.5 µA sec sec 40 126 224 410 190 700 44 139 246 451 380 1400 40 124 223 405 190 700 44 137 245 445 380 1400 See application section for equation 520 1.0 Lux to 0.01 Lux 0.01 Lux to 1.0 Lux TDR IOUT(0.01) IOUT(1.0) IOUT(10) IOUT(100) IOUT (DARK) EV = 0.01 Lux @ 25°C, Note 1,2 EV = 1.0 Lux, Note 1,2 EV = 10 Lux, Note 1,2 EV = 100 Lux, Note 1,2 EV = 0 Lux, TA = 20°C, Note 4 EV = 0 Lux, TA = 50°C, Note 4 36 114 202 369 EV = 0.01 Lux @ 25°C, Note 1,2 EV = 1.0 Lux, Note 1,2 EV = 10 Lux, Note 1,2 EV = 100 Lux, Note 1,2 EV = 0 Lux, TA = 20°C, Note 4 EV = 0 Lux, TA = 50°C, Note 4 36 112 201 365 WWW . Microsemi .C OM Parameter ≤ µA µA µA µA µLux ` Dome Bottom Package IOUT(0.01) IOUT(1.0) IOUT(10) IOUT(100) Dark Current (Equivalent Lux) IOUT (DARK) µA µA µA µA µLux Notes: 1. The input irradiance is supplied from a point source which is a white light emitting diode (LED); Fairchild Semiconductor part number MV8W00. 2. See Figure 2. 3. See Figure 3. ⎡ ⎤ 4 4. Dark Current equivalent Lux at 0 Lux: EL= ⎢ IOUT ⎥ ÷ (146 × 10 −9 ) ⎣ IREF ⎦ ELECTRICALS Output Current Output Current Output Current Output Current For Dome Top Package, IREF = 6446µA. For Dome Bottom Package, IREF= 6344µA. LX1973B Copyright © 2007 Rev. 1.3, 2008-01-11 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 3 LX1973B Automotive Light Sensor ® TM P RODUCTION D ATA S HEET TEST CIRCUITS VDD VDD VDD OUT Part White LED GND VOUT OUT Part White LED RLOAD 810nm LX1973B WWW . Microsemi .C OM VDD VOUT GND RLOAD LX1973B Figure 2 – Operational Voltage Measurement Circuit Figure 3 – IR Sensitivity Measurement Circuit APPLICATION CIRCUITS 5V LX1973B Part 10K LX1800 SCL VDD SCD REF GND AIN ADR AOUT Part 1µF 5V 2.5V DAC / ADC HI BRT Headlamp Controller Lamp Copyright © 2007 Rev. 1.3, 2008-01-11 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 LX1973B Figure 4 – Typical Application Page 4 LX1973B ® TM Automotive Light Sensor P RODUCTION D ATA S HEET APPLICATIONS GENERAL DESCRIPTION WWW . Microsemi .C OM The LX1973B 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 )= Iref 0.25 × [E DARK + E AMBIENT ] 0.25 1 Lux 1 Lux 0.25 = 10.25 Iref = 126µA for the Domed Top Package Iref = 124µA for the Domed Bottom Package EDARK = dark current equivalent Lux expressed in Lux from a white LED point source. EAMBIENT = ambient illumination expressed in Lux from a white LED point source. LX1973B Copyright © 2007 Rev. 1.3, 2008-01-11 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 5 LX1973B Automotive Light Sensor ® TM P RODUCTION D ATA S HEET SENSITIVITY DARK CURRENT VS TEMP 500 100000 450 WWW . Microsemi .C OM Dark Current (µLux) Output Current (µA) 400 350 300 250 200 150 10000 1000 100 50 0 0.001 100 0.01 0.1 1 10 100 1000 20 40 60 80 100 Temperature (C) Point Source Light (lux) NORMALIZED (PRE COMPRESSION) 100 LUX OUTPUT VOLTAGE 1.2 4.5V 5.0V 5 0.8 5.5V Output Voltage Normalized Diode Response 6 LX1973B Human Eye 1.0 0.6 0.4 0.2 4 3 2 1 0.0 -0.2 400 0 600 800 Wavelength (nm) 0 1000 IOUT VS TEMPERATURE & VDD 2 4 6 8 10 Load Resistor (in kilo-ohms) 12 14 IOUT STEP RESPONSE Iout vs Temperature @ 10 lux 225 Iout (uA) 215 205 195 -40 -20 0 20 40 60 80 LX1973B Iout @ 4.5V Iout @ 5.0V Iout @ 5.5V 100 Temperature (ºC) Load =10k and 0µF; Photo Step = Direct Light Input of 1 Lux to 0.01 Lux. Copyright © 2007 Rev. 1.3, 2008-01-11 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 6 LX1973B Automotive Light Sensor ® TM P RODUCTION D ATA S HEET PACKAGE DIMENSIONS PL D Dim MILLIMETERS MIN MAX INCHES MIN MAX A A1 A2 b c D E E1 e L L1 S θ 1.60 1.85 0.05 0.15 1.10 0.26 0.41 0.13 0.23 2.90 3.10 4.75 5.05 2.90 3.10 0.65 BSC 0.41 0.71 0.95 REF 0.525 REF 3° 0.063 0.073 0.002 0.006 0.043 0.010 0.016 0.005 0.009 0.114 0.122 0.187 0.199 0.114 0.122 0.026 BSC 0.016 0.028 0.037 REF 0.021 REF 3° D/2 8 7 6 PIN # NAME 1 VDD 2 NC 3 NC 4 OUT 5 NC 6 NC 7 NC 8 VSS E/2 5 E 1 2 3 4 S E1 R 0.9mm Typ c Note: A θ A2 Seating Plane L1 e b A1 L PR WWW . Microsemi .C OM 8-Pin Miniature Shrink Outline Package (MSOP) Dome Top 1. Dimensions do not include mold flash or protrusions; these shall not exceed 0.155mm(.006”) on any side. Lead dimension shall not include solder coverage. 8-Pin Plastic MSOP Clear Package Inverted Dome MILLIMETERS MIN MAX INCHES MIN MAX e1 8 7 6 PIN # NAME 1 VDD 2 NC 3 NC 4 OUT 5 NC 6 NC 7 NC 8 VSS A A1 A2 A3 b c D E E1 e e1 L L1 θ 1.68 0.05 0.15 0.81 0.92 0.66 0.76 0.26 0.41 0.13 0.23 2.90 3.10 4.75 5.05 2.90 3.10 0.65 BSC 1.95 TYP 0.41 0.71 0.95 REF 5° 0.066 0.002 0.006 0.032 0.036 0.026 0.030 0.010 0.016 0.005 0.009 0.114 0.122 0.187 0.199 0.114 0.122 0.026 BSC 0.077 TYP 0.016 0.028 0.037 REF 5° 5 E 1 2 3 4 b A3 L1 A1 L c LX1973B Dim D A A2 θ e Copyright © 2007 Rev. 1.3, 2008-01-11 E1 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 7 LX1973B ® TM Automotive Light Sensor P RODUCTION D ATA S HEET PACKAGE DIMENSIONS (CONTINUED) Light Footprint C L Recommended light footprint pattern P2 Dim P1 P2 MILLIMETERS 1.8 2.5 WWW . Microsemi .C OM Active Area Required Minimum Light footpri Bonding / Wafer area INCHES 0.070 0.098 Note: P2 represents a possible light footprint and its dimensions are not subject to strict tolerances. Only P1 is required to be covered with light. This larger footprint is designed to ensure coverage of the device’s active area. P1 Recommended light foot print Minimum light foot print Dome Top Package Active Area Required Minimum Light footprint Bonding / Wafer area C L Recommended light footprint pattern P2 P1 Recommended light foot print Minimum light foot print Dim P1 P2 P3 MILLIMETERS 1.8 2.5 2.9 INCHES 0.070 0.098 0.114 Note: P2 represents a possible light footprint and its dimensions are not subject to strict tolerances. Only P1 is required to be covered with light. This larger footprint is designed to ensure coverage of the device’s active area. P3 represents the minimum aperture through which the dome of the device would fit in the PCB. LX1973B P3 Recommended PCB Cutout Dome Bottom Package 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 © 2007 Rev. 1.3, 2008-01-11 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 8