AEDR-850x 3 Channel Reflective Incremental Encoders Data Sheet Description Features The AEDR-850X encoder is the smallest 3 channels optical encoder with digital outputs in the market employing reflective technology for motion control purposes. The encoder is designed to operate over -20 C to 85 C temperature range and hence suitable for both commercial and even industrial end applications. World smallest 3 channels reflective technology encoder. The encoder houses an LED light source and a photodetecting circuitry in a single package. The small size of 3.95 mm (L) x 3.4 mm (W) x 0.9562 mm (H), allows it to be even used in a wide range of miniature commercial application where size and space is a primary concern. The AEDR-850X encoder offers two-channel quadrature digital outputs and a 3rd channel, index digital outputs. Being TTL compatible, the outputs of the AEDR-850X encoder can be interfaced directly with most of the signal processing circuitries. Hence the encoder provides great design-in flexibility and easy integration into existing systems. R Surface mount leadless package 3.95 mm (L) x 3.4 mm (W) x 0.9562 mm (H) 3 channels; two channel quadrature digital outputs for direction sensing and a 3rd channel, Index digital output. Build in interpolator, factor of 1x, 2x and 4x selectable via external pinouts TTL compatible Single 5 V supply -20 C to 85 C absolute operating temperature Encoding resolution: 294 to 304 (lines/inch) Applications Ideal for high volume applications: Close Loop stepper Motors Miniature Motors VCC Printers Copiers VCC Ch A Ch B Ch I Signal Processing Circuitry SEL 4X SEL 2X Gnd Card readers Reflective Encoder Gnd Scanners Projectors Consumer and Industrial Product Applications Codewheel Note: Drawing not to scale. Note: Avago Technologies encoders are not recommended for use in safety critical applications, e.g., ABS braking systems, power steering, life support systems and critical care medical equipment. Avago's products and software are not specifically designed, manufactured or authorized for sale as parts, components or assemblies for the planning, construction, maintenance or direct operation of a nuclear facility or for use in medical devices or applications. Customers are solely responsible, and waive all rights to make claims against Avago or its suppliers, for all losses, damage, expense or liability in connection with such use. Please contact your local sales representative if more clarification is needed. Output waveform Top View P C 360 e Deg A Amplitude S1 B S2 S3 S4 Anti-clockwise Po Index of 90 e Deg option I Encoder Ch. A leads Ch. B Po Index of 180 e Deg option I Po Codewheel Index of 360 e Deg option I Note: Drawing not to scale. Codewheel rotation movement (Anti-clockwise) QUADRATURE SIGNALS A, B and I Absolute Maximum Ratings Storage Temperature, TS -20 C to 85 C Operating Temperature, TA -20 C to 85 C Supply Voltage, VCC 7V Output Voltage, VO VCC Notes: 1. Exposure to extreme light intensity (such as from flashbulbs or spotlights) may cause permanent damage to the device. 2. CAUTION: It is advised that normal static precautions should be taken when handling the encoder in order to avoid damage and/or degradation induced by ESD. 3. Proper operation of the encoder cannot be guaranteed if the maximum ratings are exceeded. Recommended Operating Conditions ( based on limited prototype samples testing @ 11.38 Rop codewheel) Parameter Sym. Min. Typ. Max. Units Temperature TA -20 25 85 C Supply Voltage VCC 4.5 5 5.5 V Ripple < 100mVp-p LED Current ILED 15mA mA See note 1 Count Frequency2 F 55 kHz 1 x Interpolation Factor Radial Misalignment ER 0.2 mm Tangential Misalignment ET 0.2 mm Codewheel Gap G 1.25 mm 0.5 1.0 Notes: 1. LED Current Limiting Resistor: Recommended series resistor = 180 (1%) 2. Count frequency = velocity (rpm) x CPR / 60. 3. Avago recommends 1.0mm gap as nominal. 2 Notes See note 3 Encoder Pin-Out Pin 8 Gnd Pin 1 VLED Emitter Pin 7 SEL 4X Pin 2 SEL 2X Detector Pin 6 VCC Pin 5 A Pin 3 CHI Pin 4 B Pin configuration (Top view) Encoder's Built-in Interpolation Pin (Interpolation) SEL 4X SEL 2X Interpolation Factor CPR @ ( ROP = 11.38 mm ) Count Frequency L L 1X 828 55 KHz L H 2X 1656 110 KHz H L 4X 3312 220 KHz H H Factory use H = HIGH Logic Level L = LOW Logic Level The interpolation factor above may be used in conjunction with the below formulae to cater the needs for various rotation speed (RPM) and count. RPM = (Count Frequency x 60 ) / CPR The CPR (@ 1X interpolation) is based on the following formulae which is directly dependent on ROP CPR = LPI x 2 x ROP (inch) or CPR = LPmm x 2 x ROP (mm) 3 Encoding Characteristics (Codewheel of Rop @11.38 mm) Encoding characteristics over the recommended operating condition and mounting conditions. Parameter Symbol Typical Interpolation factor Unit 1X 2X 4X Cycle Error C 18 22 36 e Pulse Width Error P 15 20 30 e Phase Error 9 15 18 e State Error S 10 15 25 e Index Pulse Width (Gated 90) PO 90 90 90 e Index Pulse Width (Gated 180) PO 180 180 180 e Index Pulse Width (Gated 360) PO Not Available 360 360 e Notes: 1. Typical values represent the encoder performance at typical mounting alignment, whereas the maximum values represent the encoder performance across the range of recommended mounting tolerance. 2. For optimal performance, please refer to alignment method as described in Application Note 5500 (document AV02-2789EN) Electrical Characteristics Characteristics over recommended operating conditions at 25 C. Parameter Symbol Min. High Level Output Voltage VOH 2.4 Low Level Output Voltage VOL Output current per channel, Iout IO Rise Time tr <100 ns Fall Time tf <100 ns - Typ. Max. - Unit Notes V IOH = -1.5 mA 0.4 V IOH = +1.5 mA 1.5 mA LED Current Limiting Resistor A resistor to limit the current to the LED is required. The recommended value is 180 (1%) and the resistor should be placed in series between the 5 V supply and pin VLED of the encoder. This will result in an LED current of approximately 15 mA for optimal encoder performance. CL = 25pF RL = 2.7k R VCC VLED Gnd Emitter SEL 4X SEL 2X Detector CHI VCC A 4 B Codewheel Characteristics Reflective (Ni) 3 x WB WB WW Opaque (Cu) The most important dimension to remember is that the index (I) channel pattern on the codewheel, the width angle is made up of 3 x WB (opaque-non reflective region). LW = 1.8 mm (minimum) Lw Index track Caution: As the Index track is generated by utilizing the 3xWB (opaque - non reflective) region, any dirt that blocked the tracks resulting in the encoder's detector sensing a 3x WB will result in another erroneous Index. Index track width angle is made up of 3 x W B Codewheel Design Example The following example demonstrates a codewheel design for a Rop of 11.38 mm @ 828 CPR for a typical 2 channels encoder. In the case for an index track design, special index tracks have to be utilized. 826 X 0.43478 0.21739 0.43478 828 CPR 828 CPR 0.652174 Special track Opaque (Cu) 0.21739 Opaque (Cu) Reflective (Ni) Reflective (Ni) Codewheel pattern for a 2 channels encoder Codewheel pattern for a 3 channels encoder Notes: a). 2 tracks from the original 828 CPR, 2 channels codewheel design have been utilized for the special track(Index), but CPR remains the same. 5 Recommended Codewheel Characteristics Parameter Symbol Min. Max. Window/bar Ratio Ww/Wb 0.9 1.1 Window/bar Length LW 1.80 (0.071) - Specular Reflectance Rf 60 - Reflective area. See note 1. - 10 Non reflective area Line Density LPmm LPI 11.575 Unit Notes mm (inches) 11.969 lines/mm 294 304 lines/inch Recommended LPI is 294 Notes: 1. Measurements from TMA Scan meter. 2. LPmm = CPR / [2.Rop(mm)] 3. The LED used in AEDR-850x has a typical peak wavelength of 630nm. Outline Drawing 0.7662 0.0500 0.19 0.03 0.956 TOP VIEW 2.15 Center of lens 8 X 0.350 2 X 0.900 0.50 3.40 2 X 0.900 2.62 NC 3.95 8 X O 0.30 FRONT VIEW 8 X 0.450 2 X 0.950 2 X 0.950 BACK VIEW * All dimensions in millimeter. Tolerance x.xx 0.15 mm 6 Encoder Placement Orientation and Positioning The AEDR-850X is designed such that both the emitter and detector IC should be placed parallel to the window/bar orientation, as shown (with the encoder mounted on top of the codewheel. See view below). Most importantly, the center of the lens of the encoder unit; needs to be in line with the operating radius of the codewheel (ROP) or rather the center point of Lw (0.5 of the Length of Window). Lw is recommended to be 1.8 mm or greater. Codewheel Emitter Placement orientation of the encoder's on the codewheel Codewheel Note: Drawing not to scale Detector Top View Direction of Movement With the detector side of the encoder placed closer to the codewheel centre, see the above top view; Channel A leads Channel B when the codewheel rotates anti-clockwise and vice versa (with the encoder mounted on top of the codewheel). The optimal gap setting recommended is between 0.5 to 1.25 mm (See side view below). Encoder height = 0.9562 mm Gap = 0.5 to 1.25 mm (1.0mm nominal) Codewheel Side View Codewheel Ch. A leads Ch. B Codewheel Ch. B leads Ch. A Top View Anti-clockwise Emitter Note: Drawing not to scale. 7 Clockwise Emitter Moisture Sensitivity Level The AEDR-850X is specified to moisture sensitive level (MSL) 3. Precaution is required to handle this moisture sensitive product to ensure the reliability of the product. Storage before use - Un-open moisture barrier bag (MBB) can be stored at <40'C/90%RH for 12 months. - It is not recommended to open the MBB prior to assembly. Control after open the MBB - Encoder that will be subjected to reflow solder must mounted within 168hrs of factory condition <30'C/60%RH Control for unfinished reel - Stored and sealed MBB with desiccant or desiccators at <5%RH. Baking is required if : - Humidity indicator card (HIC) is >10% when read at 235C - The encoder floor life exceeded 168 hours. - Recommended baking condition : 605C for 20 hours (tape and reel) 125 5C for 5 hours (loose unit) Recommended Land Pattern for AEDR-850X 3.40 1.45 0.35 3.95 Package outline 0.80 2.45 Front View 8 Recommended Lead-free Reflow Soldering Temperature Profile 250 Max 235 C Liquidus point 217 C 200 150 60 sec Max 100 Preheat Zone 50 0 0 25 50 60 75 100 Average ramp up rate 125 150 175 200 225 = 6C/sec Preheat temperature = 150 C to 200 C Preheat time = 60 to 100 sec Time maintain above 217 C = 40 to 60 sec Peak Temperature = 235 C Time within 5 C of peak temperature = 20 to 30 sec Note: 1. Reflow with peak temperature > 235 C may cause damage to the component. 2. Due to treatment of high temperature, this clear compound may turn yellow after IR reflow. 3. Profile shown here is the actual readings from the thermocouple (attached to AEDR-850x as shown to the right) on the reflow board PCB. 9 275 300 324 354 = 3C/sec Average ramp down rate Tape and reel information 250 Thermocouple Mold Compound IC Reflow PCB LED Ordering Information A ED R - 850x - x 0 x Index Gating 0 - Gated 90 e 1 - Gated 180 e 2 - Gated 360 e Packaging Shipping Units 1 - Tape and Reel 0 - 1000 pcs 2 - 100 pcs Note: Avago Technologies encoders are not recommended for use in safety critical applications, e.g., ABS braking systems, power steering, life support systems and critical care medical equipment. Avago's products and software are not specifically designed, manufactured or authorized for sale as parts, components or assemblies for the planning, construction, maintenance or direct operation of a nuclear facility or for use in medical devices or applications. Customers are solely responsible, and waive all rights to make claims against Avago or its suppliers, for all losses, damage, expense or liability in connection with such use. Please contact your local sales representative if more clarification is needed. For product information and a complete list of distributors, please go to our web site: www.avagotech.com Avago, Avago Technologies, and the A logo are trademarks of Avago Technologies in the United States and other countries. Data subject to change. Copyright (c) 2005-2012 Avago Technologies. All rights reserved. AV02-2790EN - June 27, 2012