AEDR-9820A-102

Data Sheet AEDR-9820A 3 Channels Reflective Incremental Encoders Analog and Digital Output (225 LPI) Description The Broadcom® AEDR-9820A is a three-channel reflective optical encoder. It can be configured to analog or digital outputs using Reflective Technology for motion control purposes. The selectable options available are two channels differential analog with a third channel differential digital or analog index output or three-channel digital differential A, B, and I output. Features    The AEDR-9820A in analog encoder modes offers two channels differential analog outputs (Sin, /Sin, Cos, /Cos), which can be interfaced directly with external interpolators that are available. The AEDR-9820A in digital encoder mode offers two-channel (AB) quadrature digital outputs and a third channel digital index outputs. Being TTL compatible, the outputs of the AEDR-9820A encoder can be interfaced with most of the signal processing circuitries. Therefore, the encoder provides easy integration into, and flexible design for, existing systems. The AEDR-9820A encoder is designed to operate over a –40°C to 125°C temperature range and is suitable for commercial, industrial, and automotive end applications. The encoder houses an infrared LED light source and photo-detecting circuitry in a single package. The small size of 4.00 mm (L) × 4.00 mm (W) × 1.05 mm (H), allows it to be used in a wide range of miniature commercial applications where size and space are primary concerns.       Analog Output option – Two channels differential analog output and differential digital or analog index output Digital Output option – Three channels differential or TTL compatible; two channel quadrature (AB) digital outputs for direction sensing and a third channel, index digital output Built-in interpolator for 1x, 2x, 4x, 8x, and 16x interpolation Surface mount leadless package – 4.0 mm (L) × 4.0 mm (W) × 1.05 mm (H) Operating voltage of 3.3V and 5.0V supply Built-in LED current regulation Wide operating temperature range from –40°C to 125°C. High encoding resolution: 225 LPI (lines/inch) or 8.86 LPmm (lines/mm) Qualified automotive standard AEC-Q100 Grade 1 Applications          Closed-loop stepper motors Small motors, actuators Industrial printers Robotics Light detection and ranging (LiDAR) Pan-tilt-zoom camera Automated guided vehicles (AGVs) Optometric equipment Linear stages Disclaimer: Except as expressly indicated in writing, the component is not designed or warranted to be suitable for use in safely-related applications where its failure or malfunction can reasonably be expected to result in injury, death, or severe equipment damage. Broadcom AEDR-9820A-DS105 September 22, 2021 AEDR-9820A Data Sheet 3 Channels Reflective Incremental Encoders Analog and Digital Output (225 LPI) Output Waveform Analog Output Option Code Wheel Rotation Movement (Anti-clockwise) Analog Parameter Definitions Analog Peak-to-Peak Vpp The peak-to-peak signal magnitude in V of the analog signal Analog Offset VOFFSET The offset in mV from the mid-point of the analog peak-to-peak signal to the zero voltage point Analog Peak/Valley Voltage VPA, VPB The value in V of the peak/valley of the analog signal (that is, one-sided reading) VMA, VMB Analog Peak to Peak Voltage Broadcom VPPA, VPPB The absolute difference between VP and VM of channel A or B AEDR-9820A-DS105 2 AEDR-9820A Data Sheet 3 Channels Reflective Incremental Encoders Analog and Digital Output (225 LPI) Digital Output Option C 360 P eDeg A Amp l i t u d e S3 S2 S1 S4 B P0 Index of 90 eDeg KƉƟon I P0 Index of 180 eDeg OpƟon I P0 I Index of 360 eDeg OpƟon Codewheel roƚĂƟon movement (CCW) Quadrature Signals A, B, and I Digital Parameter Definitions Count N The number of bar and window pairs or counts per revolution (CPR) of the code wheel. Cycle C 360 electrical degrees (°e), 1 bar and window pair. One shaft rotation: 360 mechanical degrees, N cycles. Cycle Error C 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) Error P 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 four states per cycle, each nominally 90°e. Phase  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. Optical Radius Index Pulse Width Broadcom ROP P0 The distance from the code wheel's center of rotation to the optical center (O.C.) of the encoder module. The number of electrical degrees that an index is high in one cycle. AEDR-9820A-DS105 3 AEDR-9820A Data Sheet 3 Channels Reflective Incremental Encoders Analog and Digital Output (225 LPI) Absolute Maximum Ratings Storage Temperature, TS –40°C to 150°C Operating Temperature, TA –40°C to 125°C Supply Voltage, VCC 7V ESD Human Body Model 4000V ESD Charge Device Model 1000V NOTE: 1. Proper operation of the encoder cannot be guaranteed if the maximum ratings are exceeded. 2. Caution: Take antistatic discharge precautions when handling the encoder to avoid damage, degradation, or both induced by ESD. 3. Remove Kapton tape only after SMT reflow process and just before final assembly. Take precautions to keep the encoder ASIC clean at all times. 4. Some particles may be present on the surface of the encoder ASIC surface. The presence of these particles do not degrade the performance of the encoder. Recommended Operating Condition Parameter Symbol Min. Typ. Max. Units TA –40 25 125 °C Supply Voltage VCC 2.97 3.3 3.63 V 4.5 5 5.5 Current Icc — 30 65 Pin Current (All I/O Outputs) I –20 — 20 mA Maximum Output Frequency F — — 200 kHz At 1x interpolation — — 400 kHz At 2x interpolation — — 800 kHz At 4x interpolation — — 1.6 MHz At 8x interpolation — — 2 MHz At 16x interpolation Operating Temperature mA Radial Misalignment ER — — ± 0.2 mm Tangential Misalignment ET — — ± 0.2 mm Tilt Misalignment E — — ± 2.0 deg Code Wheel Gap G 0.5 1.00 1.5 mm Notes Ripple < 100 mVp-p No load Power-Up Behavior When the AEDR-9820A is powered on, the A, B, and I digital outputs are invalid until after the initial first state of either Ch A or Ch B signal. Broadcom AEDR-9820A-DS105 4 AEDR-9820A Data Sheet 3 Channels Reflective Incremental Encoders Analog and Digital Output (225 LPI) Encoder Pinout Pin Name Function 1 CH_A / A+ Digital A+ / Analog Sin+ 2 N.C.a — 3 LED ANODE LED Anode 4 LED ANODE LED Anode 5 LED CATHODE LED Cathode 18 N.C. — 6 LED REG LED Regulation 19 INDEX_SEL — 7 VDDA / VCC Analog Supply Voltage 20 CH_BB / B- Digital B- / Analog Cos- 8 VSSA / AGND Analog Ground 21 CH_B / B+ Digital B+ / Analog Cos+ 9 SEL2 Mode Selection 2 22 VSSD / DGND Digital Ground 10 SEL1 Mode Selection 1 23 VDD Digital Supply Voltage 11 INDEX_N / I- Index Output Z- (Digital/Analog) 24 CH_AB / A- Digital A- / Analog Sin- 12 INDEX_P / I+ Index Output Z+ (Digital/Analog) 25 VSSA Analog Ground N.C. — (25) N.C. — 13 Pin Name Function 14 N.C. — 15 N.C. — 16 N.C. — 17 N.C. — a. N.C. - No connect. NOTE: 1. No connection to all corner pads indicated as (25). 2. Connect pin 8, pin 22, and pin 25 to common ground for all digital or analog mode applications. Pin 25 is the center pad of the package. 3. Both pin 7 and pin 23 need to be powered during operation. 4. Both pin 5 and pin 6 need to be connected together. Broadcom AEDR-9820A-DS105 5 AEDR-9820A Data Sheet 3 Channels Reflective Incremental Encoders Analog and Digital Output (225 LPI) Select Options – Encoder Built-in Interpolation SEL 1 SEL 2 IND SEL Interpolation Factor Index Maximum Output Frequency CPR at ROP 4.6 mm CPR at ROP 11 mm Open Open Low 1X Gated 90 deg 200 kHz 256 612 400 kHz 512 1224 800 kHz 1024 2448 1.6 MHz 2048 4896 2.0 MHz 4096 9792 200 kHz N/A N/A Open Low High Gated 180 deg Open Ungated raw Low 2X High Open High High Low Low Gated 360 deg Low 4X High Gated 180 deg Gated 360 deg Low 8X Gated 90 deg Gated 180 deg Open Low Gated 90 deg Open High High Gated 90 deg Gated 180 deg Gated 360 deg Low 16X Gated 90 deg High Gated 180 deg Open Gated 360 deg Open High N/A Analog (500 mVpp) Analog Low High N/A Analog 1 Vpp Ungated Digital High / Low Open N/A Analog 1 Vpp Analog NOTE: Open selection must be connected to middle of a voltage divider circuit. Vcc 4.7kɏ SEL 4 4.7kɏ NOTE: Recommended to use 2 × 4.7-kΩ resistors (Vcc-GND). The digital interpolation factor above may be used with the following equations to cater to various rotational speed (RPM) and count per revolution (CPR). RPM = (Count Frequency × 60) / CPR The CPR (at 1X interpolation) is based on the following equation, which is dependent on radius of operation (ROP). CPR = LPI × 2 × ROP (inch) or CPR = LP mm × 2 × ROP (mm) NOTE: Broadcom LPmm (lines per mm) = LPI / 25.4. AEDR-9820A-DS105 6 AEDR-9820A Data Sheet 3 Channels Reflective Incremental Encoders Analog and Digital Output (225 LPI) Recommended Setup for the Power Supply Pins and General Routing VDDA, VDD, and the respective grounds (VSSA and VSSD) are to be connected as shown in the following figure. The following are the recommended schematic design rules to follow:      Use a pair of 22-µF and 0.1-µF capacitors as bypass on VDD and VDDA. Place them in parallel as close as possible to the encoder ASIC package, in between the power and ground pins. Avoid routing the INDEX trace in parallel and close to the analog signals to reduce the INDEX signal switching noise from coupling into the analog signal. Design separate VDD and VDDA traces. Minimize trace or cable length where possible. For a single-ended application, do not ground the Output- from the encoder. Allow the output to float. μ μ μ μ AEDR-9820A NOTE: 1. Pin 25 is the center pad of the package and is designated as AGND. 2. Refer to the preceding table for SEL1X, SEL2X, and IND SEL configurations. Broadcom AEDR-9820A-DS105 7 AEDR-9820A Data Sheet 3 Channels Reflective Incremental Encoders Analog and Digital Output (225 LPI) Analog Encoder Characteristics Parameter Peak to Peak Voltage (Average) Analog Offset Voltage Symbol Min. Typical Max. Units VPPA, VPPB 0.9 1 1.1 V V 0.45 0.50 0.55 VOFFSETA, VOFFSETB 0.45 Vcc 0.5 Vcc 0.55 Vcc V Vref — Vcc / 2 — V Voltage Reference (Midpoint of signal Vpp) NOTE: 1. Typical values represent the average value of encoder performance in our factory-based setup conditions. 2. The optimal performance of the encoder depending on the motor/system setup condition of the individual customer. Digital Signals Characteristics (Code Wheel of Rop at 4.6 mm) Dynamic Performance Parameter Symbol Typical Interpolation Factor Units 1X 2X 4X 8X 16X ±7 ± 12 ± 21 ± 28 ± 35 °e Cycle Error C Pulse Width (Duty) Error P ±6 ± 13 ± 14 ± 18 ± 25 °e Phase Error  ±3 ±7 ±7 ±9 ±9 °e State Error S ±6 ±8 ± 11 ± 12 ± 14 °e Index Pulse Width (Gated 90°) Po 90 90 90 90 90 °e Index Pulse Width (Gated 180°) Po 180 180 180 180 180 °e Index Pulse Width (Gated 360°) Po N/A 360 360 360 360 °e Index Pulse Width (Raw Ungated) Po 330 N/A N/A N/A N/A °e NOTE: 1. Typical values represent the average value of encoder performance based on factory setup conditions at 12k RPM with the metal code wheel. 2. The optimal performance of the encoder depending on the motor/system setup and code wheel type and condition. Electrical Characteristics Characteristics over recommended operating conditions at 25°C. Parameter Symbol Min. Typ. Max. Units High Level Output Voltage VOH 2.4 — — V IOH = –20 mA Low Level Output Voltage IOH = +20 mA VOL — — 0.4 V Output current per channel, lout lo — — 20 mA Rise Timea tr — < 50 — ns Fall Timea tf — < 50 — ns Notes CL ≤ 50 pF a. Applicable for all digital modes except Index in Analog mode Broadcom AEDR-9820A-DS105 8 AEDR-9820A Data Sheet 3 Channels Reflective Incremental Encoders Analog and Digital Output (225 LPI) Code Wheel Design Guideline The window tracks are reflective surfaces, and the bar tracks are opaque surfaces; all window and bar tracks are trapezoid. The number of Incremental window/bar tracks depend on the CPR; and the Incremental windows/bars have the same width value. There is an offset between the Incremental window tracks and the Index window track. There is only one Index window track, and its width is constant. The center point to form the Incremental Optical Radius (Rop) and the Index Rop are two different points, except for 256 CPR. Figure 1: Code Wheel Design (A) Point B a Point A Broadcom AEDR-9820A-DS105 9 AEDR-9820A Data Sheet 3 Channels Reflective Incremental Encoders Analog and Digital Output (225 LPI) Figure 2: Code Wheel Design (B) d = WIncremental_window Incremental Track Index Track e = OffsetIncremental_window_left_edge-Center_Line d = WIncremental_bar Ro_Incremental c Rop_Incremental b Ri_Incremental Ro_Index b Rop_Index c f = WIndex_window Ri_Index g = OffsetIndex_window_left_edge-Center_Line NOTE: Code wheel facing up. Encoder placed on top of Code Wheel in this view. Broadcom Dimension Formula Constant for AEDR-9820A Rop_Incremental (mm) (25.4 / 225) × (CPR / 2) — Rop_Index (mm) — R4.0485 from Point B Ro_Incremental Rop_Incremental + c — Ri_Incremental Rop_Incremental – b — Ro_Index Rop_Index + b — Ri_Index Rop_Index – c — a (mm) Rop_Incremental – 4.5995 — b (mm) (0.551 – h) / 2 — c (mm) Ro_Incremental – Rop_Incremental or Rop_Index – Ri_Index ≥ 0.35 d (°) (Pitch / 2) or ((360 / CPR) / 2) — e (°) 1.25d — f (°) — 0.7031 g(°) f/2 0.3516 h (mm) Ro_Index – Ri_Incremental at Y-axis 0 ≥ h ≥ 0.05 AEDR-9820A-DS105 10 AEDR-9820A Data Sheet 3 Channels Reflective Incremental Encoders Analog and Digital Output (225 LPI) Code Wheel Design Example The following demonstrates a code wheel design for the AEDR-9820A at 256 CPR. Determine Rop_Incremental (25.4 / 225) × (256 / 2) Determine Ro_Incremental 4.5995 + 0.35 Determine Ri_Incremental 4.5995 – (0.551 / 2)  4.5995 mm  4.9495 mm  4.3240 mm Determine Pitch 360 / 256 = 1.4062° Determine d 1.406 / 2 = 0.7031° Determine e 1.25 × 0.703 = 0.8789° With the preceding information, draw a trapezoid based on Point A (0, 0), populate 256x at pitch = 1.4062° Determine a 4.5995 – 4.5995 Rop_Index = 0 mm = 4.0485 mm Ro_Index 4.0485 + (0.551 / 2) = 4.3240 mm Ri_Index 4.0485 – 0.35 = 3.6985 mm f g = 0.7031° f/2 = 0.3516° With the preceding information, draw a trapezoid based on Point B (0, 0) The following demonstrates a code wheel design for the AEDR-9820A at 1024 CPR. Determine Rop_Incremental (25.4 / 225) × (1024 / 2) Determine Ro_Incremental 18.3980 + 0.35 Determine Ri_Incremental 18.3980 – (0.551 / 2)  18.3980 mm  18.7480 mm  18.1225 mm Determine Pitch 360 / 1024 = 0.3516° Determine d 0.3516 / 2 = 0.1758° Determine e 1.25 × 0.1758 = 0.2197° With the preceding information, draw a trapezoid based on Point A (0, 0), populate 1024x at pitch = 0.3516° Determine a 18.3980 – 4.5995 Rop_Index = 13.7985 mm = 4.0485 mm Ro_Index 4.0485 + (0.551 / 2) = 4.3240 mm Ri_Index 4.0485 – 0.35 = 3.6985 mm f g = 0.7031° f/2 = 0.3515° With the preceding information, draw a trapezoid based on Point B (0, 13.7985) Broadcom AEDR-9820A-DS105 11 AEDR-9820A Data Sheet 3 Channels Reflective Incremental Encoders Analog and Digital Output (225 LPI) Code Strip Design Guideline The Incremental/Index window track is a reflective surface and the Incremental bar track is opaque. The window width is denoted by Wwindow and the bar width is denoted by Wbar. All windows and bars has the same width value, d. There is an offset between Incremental window track and Index window track, denoted by e. NOTE: Code wheel facing up. Encoder placed on top of Code Wheel in this view. Dimension Pitch (mm) Broadcom Formula 225 LPI 25.4 / LPI 0.113 a (mm) ROP_INC – ROP_INDEX 0.551 b (mm) ROP_INC – RI_INC OR RO_INDEX – ROP_INDEX a/2 c (mm) RO_INC – ROP_INC OR ROP_INDEX – RI_INDEX 0.35 d (mm) Pitch / 2 0.057 e (mm) (3 / 4) × d 0.042 AEDR-9820A-DS105 12 AEDR-9820A Data Sheet 3 Channels Reflective Incremental Encoders Analog and Digital Output (225 LPI) Multiple Index Pulse Code Wheel or Strip Design Guideline For pseudo absolute encoder applications, the multiple Index pulse can be designed into the code wheel or strip. The minimum Index bar width is 3x the incremental pitch. The recommended multiple Index pulse design guideline is shown in the following figure. Package Outline Drawing NOTE: 1. All dimensions are in mm. 2. Tolerance is x.xx ± 0.15 mm. Broadcom AEDR-9820A-DS105 13 AEDR-9820A Data Sheet 3 Channels Reflective Incremental Encoders Analog and Digital Output (225 LPI) Recommended Land Pattern NOTE: 1. All dimensions are in mm. 2. Tolerance is x.xx ± 0.05 mm. Broadcom AEDR-9820A-DS105 14 AEDR-9820A Data Sheet 3 Channels Reflective Incremental Encoders Analog and Digital Output (225 LPI) Encoder Placement Orientation, Position, and Direction of Movement The AEDR-9820A is designed with both the emitter and detector dice placed in parallel to the code wheel window/bar orientation. The encoder package is mounted on top facing down onto the code wheel. When properly aligned, the detector side will be closer to the center of the code wheel than the emitter. The optical center of the encoder package must be aligned tangential to the code wheel’s Rop. The optimal gap setting recommended is 1.00 mm, with the range of 0.50 mm to 1.50 mm. Channel A leads Channel B when the code wheel rotates anticlockwise and vice versa. Broadcom AEDR-9820A-DS105 15 AEDR-9820A Data Sheet 3 Channels Reflective Incremental Encoders Analog and Digital Output (225 LPI) Moisture Sensitivity Level The AEDR-9820A package is specified to moisture sensitive level 3 (MSL 3). Take precautions when handling this moisture-sensitive product 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. Open the MBB just prior to assembly. Control after opening the MBB Mount the encoder that will be subjected to reflow soldering within 168 hours of factory condition < 30°C/60% RH. Control for unfinished reel Store a sealed MBB with desiccant or desiccators at a < 5% RH condition. Baking is required if the following conditions exist    The humidity indicator card (HIC) is > 10% when read at 23°C ± 5°C. The encoder floor life exceeded 168 hours. The recommended baking condition is 40°C ± 5°C for 22 hours (tape and reel) or 125°C ± 10°C for 1 hour (loose units). Broadcom AEDR-9820A-DS105 16 AEDR-9820A Data Sheet 3 Channels Reflective Incremental Encoders Analog and Digital Output (225 LPI) Recommended Lead Free Solder Reflow Soldering Temperature Profile CAUTION! Exercise care when handling the encoder ASIC because it is a sensitive optical device. Remove the protective Kapton tape only after the reflow process and just before final assembly. Tape and Reel Information Broadcom AEDR-9820A-DS105 17 AEDR-9820A Data Sheet 3 Channels Reflective Incremental Encoders Analog and Digital Output (225 LPI) Reel Dimensions Ordering Information Accessories Ordering Information Part Number Description HEDS-9820EVB AEDR-9820 Evaluation Board 225 LPI Evaluation Board and Code Wheel Broadcom AEDR-9820A-DS105 18 Copyright © 2020–2021 Broadcom. All Rights Reserved. The term “Broadcom” refers to Broadcom Inc. and/or its subsidiaries. For more information, go to www.broadcom.com. All trademarks, trade names, service marks, and logos referenced herein belong to their respective companies. Broadcom reserves the right to make changes without further notice to any products or data herein to improve reliability, function, or design. Information furnished by Broadcom is believed to be accurate and reliable. However, Broadcom does not assume any liability arising out of the application or use of this information, nor the application or use of any product or circuit described herein, neither does it convey any license under its patent rights nor the rights of others.