Agilent HEDR-8130 Reflective Optical Surface Mount Encoders Data Sheet Features • Reflective technology Description The HEDR-8130 encoder uses reflective technology to sense rotary or linear position. This sensor consists of an LED light source and a photodetector IC in a single S0-8 surface mount package. When used with a reflective codewheel or codestrip, this device can sense rotary or linear position. The reflective surface mount optical encoder provides two square wave outputs in quadrature for count and direction information. These TTL-compatible outputs correspond to the alternating reflective/non-reflective pattern of the codewheel or codestrip. The HEDR-8130 can be used with a codewheel or codestrip with 150 lines per inch (5.91 lines per mm). Applications The HEDR-8130 provides two channel motion sensing at a very low cost, making it ideal for high volume applications. Its small size and surface mount capability make it ideal for printers, copiers, card readers, and consumer product applications. • Surface mount S0-8 package Note: Agilent Technologies encoders are not recommended for use in safety critical applications. Eg. ABS braking systems, power steering, life support systems and critical care medical equipment. Please contact sales representative if more clarification is needed. Theory of Operation The HEDR-8130 combines an emitter and a detector in a single surface mount S0-8 package. When used with a codewheel or codestrip, the reflective sensors translate rotary or linear motion into a two-channel digital output. The HEDR-8130 has three key parts: a single Light Emitting Diode (LED) light source, a photodetector IC with a set of uniquely configured photodiodes, and a pair of lenses molded into the package. The lens over the LED focuses light onto the codewheel or codestrip. Light is either reflected or not reflected back to the lens over the photodetector IC. • Two channel quadrature outputs for direction sensing • 3.3 V input and output • 150 lpi (5.91 lines/mm) As the codewheel rotates, or codestrip passes by, an alternating pattern of light and dark corresponding to the pattern of the codewheel falls upon the photodiodes. This light is used to produce internal signals A and A-bar, and B and B-bar. As part of this “push-pull” detector system, these signals are fed through comparators to produce the final output for channels A and B. ESD WARNING: NORMAL HANDLING PRECAUTIONS SHOULD BE TAKEN TO AVOID STATIC DISCHARGE. Definitions (Note: Refer to the Appendix for Signals Diagram.) Count (N) = The number of bar and window pairs or Counts Per Revolution (CPR) of the codewheel, or the number of Lines Per Inch of the codestrip (LPI). 1 Shaft Rotation = 360 mechanical degrees = N cycles 1 cycles (c) = 360 electrical degrees (˚e) = 1 bar and window pair Pulse Width (P): The number of electrical degrees that an output is high during one cycle. This value is nominally 180˚e or 1/2 cycle. Pulse Width Error (∆P): The deviation, in electrical degrees, of the pulse width from its ideal value of 180˚e. State Width (S): The number of electrical degrees between a transition in the output of channel A and the neighboring transition in the output of channel B. There are 4 states per cycle, each nominally 90˚e. State Width Error (∆S): The deviation, in electrical degrees, of each state width from its ideal value of 90˚e. Phase (φ): The number of electrical degrees between the center of the high state of channel A and the center of the high state of channel B. This value is nominally 90˚e for quadrature output. Phase Error (∆φ): the deviation of the phase from its ideal value of 90˚e. Direction of Rotation: When the codewheel or codestrip moves in the direction from pin 1 to pin 4, as viewed when looking down on the lenses, channel B will lead channel A. If the codewheel or codestrip moves in the opposite direction, channel A will lead channel B. Optical Radius (Rop): For rotary motion, the distance from the codewheel’s center of rotation to the center line connecting the two lenses of the encoder. Gap (G): The distance from the top of the package to the surface of the reflective codewheel or codestrip. Specular Reflectance (Rf): A measure of a surface’s reflective finish. This is quantified by the amount of light reflected when hit with an incident beam. A device called a scatterometer is used to quantify specular reflectance on a percent scale. (Contact factory for more information.) Radial and Tangential Misalignment Error ER, ET): For rotary motion, mechanical misalignment in the radial and tangential directions relative to the codewheel. Angular Misalignment Error (EA): Angular misalignment of the sensor in relation to the tangential direction. This applies for both rotary and linear motion. Absolute Maximum Ratings Parameter Storage Temperature Operating Temperature Supply Voltage Output Voltage Output Current per Channel 2 Symbol TS TA VCC VO IO Min. –40 –10 –0.5 –0.5 –0.2 Max. 85 85 5 VCC 9 Units ˚C ˚C V V mA Notes Recommended Operating Conditions Parameter Temperature Supply Voltage LED Current Symbol T VCC ILED Min. –10 3 13 Load Capacitance Pull-Up Resistor CL RL Count Frequency Redial Misalignment ER Tangential Misalignment ET Angular Misalignment Codewheel or Codestrip Gap EA G 0.2 Codewheel or Codestrip Specular Reflectance Codewheel/Codestrip Tilt Codewheel/Codestrip Resolution Rf 60% Typ. 25 3.3 16 Max. 85 3.5 18 Units ˚C V mA 100 pF KΩ none CT LPmm (LPI) 0.0 1.4 0 5.91 (150) 15 ± 0.38 (± 0.015) ± 0.38 (± 0.015) ± 1.5 2.00 kHz mm (in.) mm (in.) deg. mm 1 deg. lines/mm (lines/in.) Notes Ripple < 100 mV p-p See ”Current Limiting Resistor for LED“ Recommend no pull-up. Device has integrated 2.5 KΩ on outputs. (Velocity (rpm) x N)/60 1.4 mm is the recommended gap but the unit can operate from 0.2 to 2 mm with no problem As other rose products, eg., HEDR-8100 series HEDR-8130 is 150 lpi Encoding Characteristics Encoding Characteristics over Recommended Operating Conditions and Mounting Conditions. Parameter Pulse Width Error Phase Error State Error 3 Symbol P φ S Typical 16 10 30 Max. 75 60 75 Units ˚e ˚e ˚e Notes HEDR-8130 HEDR-8130 HEDR-8130 Electrical Characteristics Electrical Characteristics over Recommended Operating Conditions. Typical Values at 25˚C. Parameter Supply Current High Level Output Voltage Low Level Output Voltage Rise Time Symbol I CC VOH VOL tr Fall Time tf Current Limiting Resistor for LED A resistor to limit current to the LED is required. The recomended value is 110 Ω (± 10%) and should be placed in series between the 3.3 V supply and pin 8 of the device (V LED). This will result in an LED current of approximately 16 mA. Min. Typ. 3 150 Max. 5 3.3 0.4 200 Units mA V V ns 50 60 ns 2.4 Notes IOH = –140 µA IOL = 8 mA CL = 25 pF RL = 2.7 KΩ Recommended Codewheel and Codestrip Characteristcs Wb Ww Lw ROP Lw Ww Wb Table 1. Parameter Window/Bar Ratio Specular Reflectance Symbol Ww/Wb Rf Line Density LPmm (LPI) Lw Window Length 4 Min. 0.9 60 – 1.80 (0.071) Max. 1.1 85 10 5.91 (150) 2.31 (0.091) Units Notes Reflective Bars Non-reflective Bars lines/mm (lines/inch) mm (inches) mm (inches) Mounting Conditions 1 2 3 4 8 7 6 5 ROP 11.00 mm (0.433 IN.) < ROP < ∞ 1. 150 ± 10˚C for 90 ± 30 seconds 2. Greater than 200˚C for 30 ± 10 seconds 3. 230 ± 5˚C for 10 ± 1 seconds 30 ± 10 S 10 ± 1 S TEMPERATURE (°C) IR Soldering Conditions The following recommended IR soldering profile meets the specifications of the Electronic Industries Association of Japan (EIAJ): 235°C MAX. 230°C ± 5°C 200°C 90 ± 30 S 150°C ± 10°C TIME (S) Ordering Information H E D R - 8 1 3 0 Opt 2 signifies 3.3 V Lines/Inch P = 150 lpi 5 Units in Shipping Tube 4 = 1500 units Outline Drawing 8 7 6 5 3.937 ± 0.076 * (0.155 ± 0.003) 1 NC VLED 8 NC 7 B 6 GND 5 2 GND 6.20 ± 0.20 (0.244 ± 0.008) 3 A REF. 1 2 3 4 VCC 4 1.270 ± 0.025 (0.050 ± 0.001) 0.381 ± 0.050 (0.016 ± 0.002) 5.080 ± 0.100 * (0.200 ± 0.004) 1.877 / 1.775 (0.0739 / 0.0699) 1.40 ± 0.20 (0.055 ± 0.001) 0.076 ± 0.025 (0.003 ± 0.001) 3.175 ± 0.076 (0.125 ± 0.003) LEAD COPLANARITY ± 0.051 (0.002) XXXX YYWW 6 0.228 ± 0.025 (0.009 ± 0.001) 0.18 ± 0.08 (0.007 ± 0.003) 0.59 MIN. (0.023) NOTES: 1. DO NOT INCLUDE FLASH IN DIMENSIONS MARKED WITH AN *. 2. DEVICE MARKING ORIENTATION IS AS SHOWN. DATE CODE IS YEAR/WORKWEEK (YYWW). PART NUMBER IS XXXX. 3. DIMENSIONS IN MILLIMETERS (INCHES). Appendix Note: For Definitions in page 2 and Electrical Characteristics in page 3. C P CHANNEL A AMPLITUDE Φ S1 S2 S3 S4 2.4 V CHANNEL B 0.4 V tf tr ROTATION 7 www.agilent.com/semiconductors For product information and a complete list of distributors, please go to our web site. For technical assistance call: Americas/Canada: +1 (800) 235-0312 or (408) 654-8675 Europe: +49 (0) 6441 92460 China: 10800 650 0017 Hong Kong: (+65) 6271 2451 India, Australia, New Zealand: (+65) 6271 2394 Japan: (+81 3) 3335-8152(Domestic/International), or 0120-61-1280(Domestic Only) Korea: (+65) 6271 2194 Malaysia, Singapore: (+65) 6271 2054 Taiwan: (+65) 6271 2654 Data subject to change. Copyright © 2002 Agilent Technologies, Inc. May 3, 2002 5988-5014EN