AEDR-8712-102

AEDR-871x 3-Channel High Resolution Reflective Incremental Encoder (Digital Outputs) Data Sheet Description Features The AEDR-871x encoder is the smallest 3-channel optical encoder with digital outputs that employs Reflective Technology for motion control. • World's smallest 3-channel reflective technology encoder The encoder is designed to operate over the -20 °C to 85 °C temperature range and so is suitable for both commercial and industrial applications. • Digital Output option - 3 channels TTL compatible; 2 channel quadrature (AB) digital outputs for direction sensing and a third channel, Index digital output. Builtin interpolator for 4×, 8× and 16× interpolation. AEDR-871x offers high resolution (318 LPI) with built-in interpolation, enabling great flexibility and versatility in resolution range. • Surface mount leadless package 3.95 mm (L) × 3.4 mm (W) × 0.9562 mm (H) The compact dimensions of 3.95 mm (L) × 3.4 mm (W) × 0.9562 mm (H) coupled with the low operating 3.3 V option allows it to be used in a wide range of miniature commercial applications and portable devices in which space and power consumption is a primary concern. • Built-in LED current regulation, removing need for external biasing resistor AEDR-871x encoder offers two-channel (AB) quadrature digital outputs and a third channel, index digital outputs. Being TTL compatible, the outputs of the AEDR-871x encoder can be interfaced directly with most of the signal processing circuitries. Therefore, the encoder provides great design-in flexibility and easy integration into existing systems. • Operating voltage of 3.3 V or 5 V supply • -20 °C to 85 °C absolute operating temperature • Encoding resolution: 318 (lines/inch, LPI) Applications Ideal for high volume applications: • Miniature motors • Printers and copiers • Card readers • Miniature camera module • Portable measurement devices • Healthcare, lab diagnostic equipment and portable devices • Optometric equipment • Consumer and industrial product applications Output Waveform Top View P C 360 e Deg Amplitude A S1 B S2 S3 φ S4 Anti-clockwise Po Index of 90 e Deg option I I I Po Encoder CH A leads CH B Index of 180 e Deg option Po Codewheel Index of 360 e Deg option Codewheel rotation movement (Anti-clockwise) Note: Drawing not to scale QUADRATURE SIGNALS A, B and I Test Parameter Definitions Parameter Symbol Description Count N The number of bar and window pairs, or counts per revolution (CPR), of the codewheel. One Cycle C 360 electrical degrees (°e), 1 bar and window pair. One Shaft Rotation 360 mechanical degrees, N cycles. Cycle Error ΔC An indication of cycle uniformity. The difference between an observed shaft angle that gives rise to one electrical cycle, and the nominal angular increment of 1/N of a revolution. Pulse Width (Duty) P The number of electrical degrees that an output is high during 1 cycle. This value is nominally 180°e or 1/2 cycle. Pulse Width (Duty) Error ΔP The deviation, in electrical degrees, of the pulse width from its ideal value of 180°e. State 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 Error ΔS 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 Δφ The deviation of the phase from its ideal value of 90°e. Optical Radius ROP The distance from the codewheel’s center of rotation to the optical center (O.C.) of the encoder module. Index Pulse Width PO The number of electrical degrees that an index is high during one full shaft rotation. 2 Absolute Maximum Ratings Parameter Value Storage Temperature, TS -20 °C to 85 °C Operating Temperature, TA -20 °C to 85 °C Supply Voltage, VCC 7V Notes: 1. Exposure to extreme light intensity (such as from flashbulbs or spotlights) may cause permanent damage to the device. 2. CAUTION: To avoid damage or degradation induced by ESD, take normal static precautions when handling the encoder. 3. Proper operation of the encoder cannot be guaranteed if the maximum ratings are exceeded. Recommended Operating Conditions Parameter Symbol Min. Typ. Max. Units Operating Temperature TA -20 25 85 °C Supply Voltage VCC 3.0 3.3 3.6 V 4.5 5 5.5 Notes Ripple < 100 mVp-p Current ICC - 27 60 mA Output Frequency F - - 240 kHz 4× Interpolation F - - 480 kHz 8× Interpolation F - - 960 kHz 16× Interpolation Radial Misalignment ER - - ± 0.2 mm Tangential Misalignment ET - - ± 0.2 mm Codewheel Gap G 0.5 0.75 1.0 mm Parameter Symbol Min. Max. Unit Notes Window/Bar Ratio WW/WB 0.9 1.1 Window/Bar Length LW 1.80 (0.071) - Specular Reflectance Rf 60 - Reflective area [1] - 10 Non-reflective area Recommended Codewheel Characteristics Line Density Notes: 1. Measurements from TMA µScan meter 2. LPmm = CPR/[2π.Rop(mm)] 3 mm (inches) LPmm 12.52 lines/mm LPI 318 lines/inch Encoder Pinouts VDDD VDDA VDDA CH A AGND CH A AGND DGND DGND CH B SEL 1 CH I VDDD SEL 1 CH B SEL 2 SEL 2 Pin Configurations (Top View) CH I Pin Configurations (Bottom View) Digital Option - Encoder's Built-in Interpolation Pin (Interpolation) SEL 1 SEL 2 Example of CPR Interpolation Factor Max. output frequency @ ROP = 11 mm H H 4× 240 kHz 3460 L L 8× 480 kHz 6920 H L 16× 960 kHz 13840 H = HIGH Logic Level L = LOW Logic Level This interpolation factor may be used in conjunction with the following formula to cater to the need for various rotation speeds (RPM) and counts. RPM = (Count Frequency × 60 )/CPR The CPR (@1× interpolation) is based on the following formula, which is directly dependent on ROP: CPR = LPI × 2π x ROP (inch) or CPR = LPmm × 2π × ROP (mm) Note: LPmm (lines per mm) = LPI/25.4 Recommended Setup For the Power Supply Pins Connect both VDDD, VDDA and their corresponding grounds (AGND and DGND) appropriately as follows. It is recommended that you use 22 µF and 0.1 µF for bypass capacitor on VDDD and VDDA and place them in parallel as close as possible to the power and the ground pins. VCC 0.1 µF 22 µF 9 DGND 4 6 1 VDDA CH A AGND CH B SEL1X CH I 5 SEL2X 4 SEL2X CH B 7 8 VDDD CH I CH A 22 µF Notes: 1. DGND (Pin 9) is the center pad of the package. 2. For SEL1X and SEL2X configuration, see the Digital Option - Encoder's Built-in Interpolation table. 2 3 0.1 µF SEL1X Encoding Characteristics (Code wheel of ROP @ 11 mm) Dynamic Performance Parameter Symbol Interpolation Factor Typical Unit 4× 8× 16× Cycle Error ΔC ±17 ±28 ±35 °e Pulse Width (Duty) Error ΔP ±14 ±18 ±22 °e Phase Error Δ∅ ±5 ±8 ±9 °e State Error ΔS ±8 ±10 ±13 °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 360 360 360 °e Notes: 1. Typical values represent the average values of encoder performance in our factory-based setup conditions. 2. The optimal performance of encoder depends on the motor/system setup condition of the individual customer. Electrical Characteristics Characteristics over recommended operating conditions at 25 °C. Parameter Symbol Min. Typ. Max. Unit Notes High Level Output Voltage VOH 2.4 - - V IOH = -4mA Low Level Output Voltage VOL - - 0.4 V IOH = +4mA Output current per channel, lout lo - - 4 mA Rise Time tr - < 100 - ns Fall Time tf - < 100 - ns 5 CL ≤ 50 pF Codewheel Design Guideline The index bar (I-) track is opaque and the width is 3 × WB°. The Index (I) track is reflective and the width is 3 × WW°. The dimension LW should be at least 1.8 mm. (Note: If LW shorter than 1.8 mm is required, please consult factory) There are 6 pairs of incremental track (1 pair= 1 WB° and 1 WW°) between opaque and reflective index tracks. Note: Encoder is placed on top on this codewheel in this view WW° WB° Opaque Surface 6×(WW°+WB°) Reflective Surface 3×WB° (Index Bar Track) LW 3×WW° (Index Track) Codewheel design example The following demonstrates a codewheel design for Rop of 11 mm @ 865 CPR for a 2-channel and a 3-channel encoder. Reflective Surface 0.4162° 0.2081° Opaque Surface Pitch= 360/CPR=360/865=0.4162° WW° and WB° = 360/(2×CPR) = 360/(2×865)=0.2081° 865CPR Codewheel pattern for a 2-channel encoder 6 1.8 0.4162° 0.2081° 0.2081° 0.6243° Opaque Surface WW° and WB° = 360/(2×CPR) = 360/(2×865)=0.2081° Index Width = 3×WW° = 0.6243° Index Bar Width = 3×WB° = 0.6243° 2.4971° Reflective Surface 0.6243° Codewheel pattern for a 3-channel encoder Note: The overall physical track count is reduced but not the counts per revolution (CPR). The CPR remains the same because the count during this index transition is generated by an intelligent signal processing circuit. Package Outline Drawing 0.9562 Note: Unless otherwise specified, 1. All dimensions in mm 2. Tolerance x.xx ± 0.15mm TOP VIEW 3.40±0.20 0.50 Center of Lens 8×0.350 3.95±0.20 2×0.90 2.15 2×0.90 2.62 8×0.450 2×0.95 FRONT VIEW 7 2×0.95 BACK VIEW Recommended Land Pattern 3.40 0.5 2×3.00 Package outline 2×1.8 2.15 8 ×0.35 3.95 8 ×0.80 2×1.9 All dimensions in mm Tolerance x.xx ± 0.05mm 2×2.45 Encoder Placement Orientation and Positioning The AEDR-871x is designed such that both the emitter and the detector ICs are placed parallel to the window/bar orientation, with the encoder mounted on top of the codewheel (see below right). When properly oriented, the detector side will be closer to the center of codewheel than the emitter. More importantly, the center of the lens of the encoder unit must be aligned with the codewheel (ROP), or more specifically tangential to the center point of LW (1/2 of the length of window). Codewheel Codewheel Codewheel Emitter (LED) Placement orientation of the encoder’s emitter and detector on the codewheel 2.62 Detector Center of Codewheel Center of the lens should be aligned with the ROP of the codewheel 8 Direction of Movement With the detector side of the encoder placed closer to the codewheel (see picture on the previous page), 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 1.0 mm (see the side view below). Encoder height = 0.9562 mm Gap = 0.5 to 1.0 mm Codewheel Side View Codewheel CH A leads CH B Codewheel CH B leads CH A Top View Emitter Anti-clockwise Emitter Clockwise Note: Drawing not to scale Moisture Sensitivity Level The AEDR-871x is specified to Moisture Sensitive Level (MSL) 3. Precaution is required to handle this moisture-sensitiveproduct to ensure the reliability of the product. Storage before use • An unopened Moisture Barrier Bag (MBB) can be stored at < 40 °C/90% RH for 12 months. • It is not recommended that the MBB is opened before assembly. Control after the MBB is opened • Encoder that will be subjected to reflow solder must be mounted within 168 hours of factory condition 10% when read at 23 ± 5 °C • The encoder floor life exceeded 168 hours. • Recommended baking condition: 60 ± 5 °C for 20 hours (tape and reel), 125 ± 5 °C for 5 hours (loose unit) 9 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 75 100 125 150 175 200 Average ramp up rate = 3 °C/sec Average ramp down rate = 6 °C/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 225 Notes: 1. Reflow with peak temperature > 235 °C may damage 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-871x as shown to the right) on the reflow board PCB. Tape and Reel Information 10 250 275 300 324 354 Thermocouple Mold Compound IC Reflow PCB LED Order Information AEDR – 87xx – x 0 x Output Signal Index Gating Packaging Resolution LPI Shipping Units 1 – Digital 2 – Analog 0 – Gated 90ºe 1 – Gated 180ºe 2 – Gated 360ºe 3* – Tag 360ºe 1 – Tape and Reel 0 – 318 0 – 1000 pcs 2 – 100 pcs Notes: Digital 3.3 V and 5 V operating mode Analog: 5 V operating mode only Index Gating: 3* applicable only for analog output DISCLAIMER: Avago’s products and software are not specifically designed, manufactured or authorized for sale as parts, components or assemblies for the planning, construction, maintenenace or direct operation of a nuclear facility or for use in medical devices or applications. Customer is solely responsible, and waives all rights to make claims against Avago or its suppliers, for all loss, damage, expense or liability in connection with such use. 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 © 2005-2014 Avago Technologies. All rights reserved. AV02-4517EN - June 6, 2014