655 nm Precision Optical Reflective Sensor Technical Data HEDS-1500 Features * Focused Emitter and Detector in a Single Package * 655 nm Visible Emitter * 0.178 mm (0.007) Resolution * TO-5 Miniature Sealed Package * Photodiode Output emitter and a matched I.C. photodetector. A bifurcated aspheric lens is used to image the active areas of the emitter and the detector to a single spot 4.27 mm (0.168 in.) in front of the package. The output signal is a current generated by the photodiode. Applications Description The HEDS-1500 is a fully integrated module designed for applications requiring optical reflective sensing. The module contains a 655 nm visible LED Applications for the HEDS-1500 include bar code scanning, pattern recognition and verification, object sizing, optical limit switching, tachometry, textile thread counting and defect detection, dimensional monitoring, line locating, paper edge detection, and any application where precision optical reflective sensing is desired. Mechanical Considerations The HEDS-1500 is packaged in a high profile 8 pin TO-5 metal can with a glass window. The emitter and photodetector chips are mounted on the header at the base of the package. Positioned above these active elements is a Package Dimensions 9.40 (0.370) 8.51 (0.335) MAXIMUM SIGNAL POINT S.P. 5.08 (0.200) 0.86 (0.034) 0.73 (0.029) REFERENCE PLANE 4.27 0.25 (0.168 0.010) R.P. 8.33 (0.328) 7.79 (0.307) CL 5.08 (0.200) 12.0 (0.473) 4.11 (0.162) 1.14 (0.045) 0.73 (0.029) 15.24 (0.600) 12.70 (0.500) NOTES: 1. ALL DIMENSIONS IN MILLIMETERS AND (INCHES). 2. ALL UNTOLERANCED DIMENSIONS ARE FOR REFERENCE ONLY. 3. THE REFERENCE PLANE (R.P.) IS THE TOP SURFACE OF THE PACKAGE. 4. NICKEL CAN AND GOLD PLATED LEADS. 5. S.P. = SEATING PLANE. 6. THE LEAD DIAMETER IS 0.45 mm (0.018 IN.) TYP. 11.50 (0.453) 11.22 (0.442) 2 bifurcated aspheric acrylic lens that focuses them to the same point. The sensors can be rigidly secured by commercially available two piece TO-5 style heat sinks, such as Thermalloy 2205, Aavid Engineering 321527, or 8 pin 0.200 inch diameter pin circle sockets. These fixtures provide a stable reference platform for affixing the HEDS-1500 to a circuit board. In applications requiring contact scanning, protective focusing tips are available. Focusing tips are available in either metal or polycarbonate packages using a sapphire ball as the contact surface. The Agilent part numbers are HEDS-3001, HBCS-2999, HBCS-4999, HBCS-A998, and HBCS-A999. Applications that require modulation or switching of the LED should be designed to have the cathode connected to the electrical ground of the system. Electrical Operation The detector of the sensor is a single photodiode. Figure 7 shows photocurrent being supplied from the cathode of the photodiode to an inverting input of the operational amplifier. The cathode of the 655 nm emitter is physically and electrically connected to the case-substrate of the device. SCHEMATIC DIAGRAM Applications where ambient light is present will require a special LED drive and recovery circuit to achieve the full resolution of the sensor. Application Note 1040 provides data and schematics to support HEDS-1500 sensor operation in ambient light conditions. A reliability data sheet is available for the HEDS-1500 precision optical reflective sensor. CONNECTION DIAGRAM REFLECTOR REFERENCE PLANE Z 8 1 7 DPS RS 2 6 LED DPS 6 LED 1 3 8 2 FUNCTION 1 2 4 6 8 PHOTODIODE CATHODE HEADER GROUND ** LED ANODE PHOTODIODE ANODE **CUSTOMER SHOULD NOT CONNECT GROUND TO PIN 4. INTERNAL CONNECTION TO PIN 4 WILL BE DELETED IN THE FUTURE. 4 RS 4 5 PIN # TOP VIEW CASE, SUBSTRATE RS - CHARACTERISTIC NOT DEFINED Absolute Maximum Ratings @ TA = 25C Parameter Symbol Min. Max. Units Operating Temperature TA -20 70 C Storage Temperature TS -40 75 C 260 for 10 sec. C mA Lead Soldering Temperature Average LED Forward Current If 50 Peak LED Forward Current Ifp (data pending) Reverse LED Input Voltage Vr 5 V Photodiode Bias (-V = forward bias) Vd 7 V (See next page for Notes.) -0.3 Note 1 2 3 3 Electrical/Optical Characteristics at TA = 25C Parameter Reflected Photocurrent Quality Factor Symbol Min. Typ. Max. Units Conditions Note Figure Ipr 80 125 - nA If = 35 mA 4, 5, 11 1, 2, 4, 7 <Q> 0.82 0.95 1.0 - If = 35 mA 4, 6 Maximum Signal Point (MSP) Z LED Forward Voltage Vf - 1.72 1.86 V If = 35 mA BVR 5.0 - - V Ir = 100 A Id - 50 1000 pA V d = 5 V, If = 0 lambda 655 670 nm If = 35 mA Ipr Temperature Coefficient Ke -0.006 1/C System Optical Step Response Size (OSR) d 0.154 (0.006) mm (inch) LED Reverse Breakdown Voltage Photodiode Dark Current LED Peak Wavelength 4.01 4.27 4.52 mm (0.158) (0.168) (0.178) (inch) 4, 7 4 3 8 5 9 - 10 8 Notes: 1. CAUTION: The thermal constraints of the acrylic lens will not permit conventional wave soldering procedures. The typical preheat and post-soldering cleaning procedures and dwell times can subject the lens to thermal stresses beyond the absolute maximum ratings and can cause it to defocus. 2. (Reliability tests are proceeding--data not yet available.) 3. Id (max) = 100 A. Recommended operation: Vd (min) = 0 V Vd (max) = 5 V Exceeding maximum conditions may cause permanent damage to photodiode or to chip metallization. 4. Measured from a reflector coated with 99% diffuse reflective white paint (Kodak 6080) positioned 4.27 mm (0.168 in.) from the reference plane. (See "Photocurrent Test Circuit" for test connection.) Measured physically is the total photocurrent, Ipt, which consists of a signal (reflected from target) component, Ipr, and a component induced by reflection internal to the sensor (stray), Ips . Ipt = Ipr + Ips Specified is the reflected signal component, Ipr. 5. See Bin Table. 6. <Q> = Ipr/Ipt. 7. Measured from the reference plane (R.P.) of the sensor. 8. Leakage current of photodiode measured in the dark. 9. Photocurrent variation with temperature varies with LED output which follows a natural exponential law: Ip(T) = Ip(To)*exp[Ke(T-To)]. 10. OSR size is defined as the distance for a 10%-90% "step" response of Ipr as the sensor moves over an abrupt step from opaque white to black, or from opaque white to free space (no reflection). 11. Sensor contains no ambient light filtering--see Figure 6 for relative response of detector. In bright ambient light conditions, LED signal may be a small portion of total signal. AC coupling and additional signal processing may be necessary. Reference Application Note 1040. 4 Product Marking BIN TABLE The photocurrent binning of the sensor is incorporated as part of the date code format, assigned at time of test--"CTYYWWan", where: Ipr LIMITS BIN # MIN. MAX. 1 2 3 4 5 6 7 80 105 125 150 180 215 270 110 nA 135 155 190 220 275 320 C = letter identifying country of assembly--S = Singapore If blank = USA T = tester code designation letter (single letter) YY = last two digits of year WW = week number in year OPTICAL SYSTEM EMITTER 0.185 mm DIA. JUNCTION BAFFLE ACRYLIC SEAL a = single lot code letter (A - Z), sequential assignment during week n = bin number SENSING AREA GLASS DETECTOR 0.406 mm SQUARE LENS REFLECTOR REFERENCE PLANE +Vf 6 LED If 1 DPS 8 2 RS 4 CASE, SUBSTRATE Figure 1. Photocurrent Test Circuit. See Figure 7 for suggestion in the application of photocurrent bins. Test algorithm bins units to the lowest bin number if a unit is in the overlap region. Such units can cross bin boundaries as temperature changes. (Ambient temperature affects LED efficiency slightly and may cause several percent change in Ipr). Bin numbers are for "reference only" and do not constitute an absolute guarantee. Z The output of all LEDs degrade with time, depending on drive conditions and temperature. IPT The entire available distribution of parts, appropriately marked, will be shipped. Single bin orders cannot be supplied. nA-METER 5 2.0 VF - FORWARD VOLTAGE - V PHOTOCURRENT NORMALIZED AT IF = 35 mA, 25 C 3.0 2.5 2.0 1.5 1.0 0.5 0 1.9 1.8 1.7 1.6 1.5 1.4 1.3 1.2 1.1 1.0 1 A 0 10 20 30 40 50 60 70 80 90 100 IF - FORWARD CURRENT - mA IF - FORWARD CURRENT Figure 2. Relative Reflected Photocurrent. Figure 3. LED Forward Voltage vs. Forward Current. SENSOR MSP RANGE 1.75 LED LIGHT OUTPUT (NORMALIZED TO 25 C VALUE) PHOTOCURRENT NORMALIZED TO PEAK @ MSP 1.0 MSP = 4.01 mm 0.8 0.6 0.4 0.2 MSP = 4.52 mm 0 3.0 3.5 4.0 4.5 5.0 1.50 -20 C NORMALIZED 1.25 0 C NORMALIZED 1.00 25 C NORMALIZED 0.75 70 C NORMALIZED 0.50 0.25 0 595 5.5 10 A 100 A 1 mA 10 mA 100 mA 615 6.0 635 655 675 695 715 WAVELENGTH - nm DISTANCE FROM REFERENCE PLANE OF SENSOR - mm RESPONSE NORMALIZED TO PEAK Figure 4. Photocurrent Variation with Distance. Figure 5. 655 nm Emitter Typical Spectral Distribution. 1.0 0.8 0.6 0.4 0.2 0 550 600 650 700 750 800 850 900 WAVELENGTH - nm Figure 6. Relative Spectral Response of Sensor. REFLECTOR C1 REFERENCE PLANE Z Rf VO = [(R1 + R2)/R2] x Rf x IPT +5 V IPT If 6 VO 1 DPS LED - 8 + 4 C2 R1 RS 2 R2 CASE, SUBSTRATE C1 - LIMITS BANDWIDTH OF PRE-AMP. C2 - AC-COUPLING MAY BE NECESSARY IN HIGH LIGHT AMBIENT CONDITIONS. Rf - FOR OPTIMUM PERFORMANCE, Rf SHOULD BE SELECTED TO MATCH BIN NUMBER OF SENSORS SO AS TO MAINTAIN VO IN DESIRED RANGE. d - SYSTEM RESPONSE - mm 1.0 0.8 CUSP PERPENDICULAR TO EDGE OF STEP 0.6 NORMALIZED SIGNAL Figure 7. Sensor with Transimpedance Amplifier. 100 % WHITE 90 % d 10 % 0 BLACK 0.4 0.2 0 2.7 LENS CUSP PARALLEL TO EDGE OF STEP 3.1 3.5 3.9 4.3 4.7 5.1 5.5 5.9 DISTANCE FROM REFERENCE PLANE OF SENSOR - mm Figure 8. System Optical Step Response Variation with Distance. Warranty and Service Agilent Optical Reflective Sensor is warranted for a period of one year after purchase covering defects in material and workmanship. Agilent will repair or, at its option, replace products that prove to be defective in material or workmanship under proper use during the warranty period. NO OTHER WARRANTIES ARE EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. AGILENT IS NOT LIABLE FOR CONSEQUENTIAL DAMAGES. For additional warranty or service information please contact your local Agilent sales representative or authorized distributor. www.semiconductor.agilent.com Data subject to change. Copyright (c) 1999 Agilent Technologies Obsoletes 5952-2227E 5091-7285E (11/99)