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Technical content

Features

  • Two-channel quadrature output with ungated index pulse (A,B,I)
  • Three-channel integrated commutation Output (UVW)
  • 360/720 Cycle Per Revolution (CPR)
  • Easy assembly with alignment jig
  • Design to fit into circular shaped housing
  • Up to 150 kHz frequency response
  • -40°C to 100°C operating temperature
  • TTL Compatible
  • Single 5V Supply
  • Integrated feedback device for Brushless DC Motor
  • RoHS Compliant

Applications

Typical applications include industrial printers, plotters, tape drives, industrial and factory automation equip - ment. Note: Avago Technologies encoders are not recommended for use in safety critical application, e.g., ABS braking systems, power steering, life sup - port systems and critical care medical equipment. Please contact sales representative if more clarification is needed. AEDS-9240 Series 360/720 CPR Commutation Encoder Module Data Sheet

The AEDS-9240 optical encoder is an emitter/detector module. Coupled with a codewheel, these modules trans- late the rotary motion of a shaft into a six-channel digital output. The modules contain a single Light Emitting Diode (LED) as its light source. The light is collimated into a parallel beam by means of a single polycarbonate lens located di- rectly over the LED. Opposite the emitter is the integrated detector circuit. This IC consists of multiple sets of photo detectors and the signal processing circuitry necessary to produce the digital waveforms. The codewheel rotates between the emitter and detector, causing the light beam to be interrupted by the pattern of spaces and bars on the codewheel. The photodiodes that detect these interruptions are ar - ranged in a pattern that corresponds to the radius and design of the code-wheel. These detectors are also delib - erately spaced such that a light period on one pair of de - tectors corresponds to a dark period on the adjacent pair of detectors. The photodiode outputs are then fed through the signal processing circuitry resulting in A, /A, B, /B, I, and /I. Com - parators receive these signals and produce the final out - puts for channels A and B. Due to this integrated phasing technique, the digital output of channel A is in quadra - ture with that of channel B (90 mechanical degrees out of phase). The commutation feedback (U, V, W) signals are generated based on the codewheel design. Definition Count (N): The number of electrical cycles per revolution (CPR). CPR refers to the raw signal from encoder that is the cycles before 4x decode. One Cycle: 360 electrical degrees (°e). One Shaft Rotation: 360 mechanical degrees. Cycle Error (ΔC): An indication of cycle uniformity. The dif - ference between an observed shaft angle which gives rise to one electrical cycle, and the nominal angular increment of 1/N of a revolution. Pulse Width (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 Error (ΔP): The deviation, in electrical degrees, of the pulse width from its ideal value of 180°e. State Width (S): The numbers of electrical degrees between transitions in the output of channel A and the neighbor - ing transition in the output of channel B. There are 4 states per cycle, each nominally 90°e. State Width Error (ΔS): The deviation, in electrical degrees, of each state width from its ideal value of 90°e. Commutation Accuracy (ΔI): The deviation, in mechanical degrees, after shaft rotates passes the reference point (In- dex channel) to the first U channel pulse. The measure - ment from middle of channel I to channel U. Phase (f): The numbers 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 (Δf): The deviation of the phase from its ideal value of 90°e. Direction of Rotation: When the codewheel rotates in the clockwise direction viewing from top of the module, chan- nel A will lead channel B. If the codewheel rotates in the opposite direction, channel B will lead channel A. Optical Radius (Rop): The distance from the codewheel’s center of rotation to the optical center (O.C) of the encod- er module. Index Pulse Width (Po): The number of electrical degrees that an index is high with reference to channel A or chan- nel B during one full shaft rotation

AEDS-9240 Technical Specifications Absolute Maximum Ratings Parameter Symbol Min. Max. Units Notes Storage Temperature TS -40 100 °C Operating Temperature TA -40 100 °C Supply Voltage VCC -0.5 7 Volts Recommended Operating Conditions Parameter Min. Typ. Max. Units Notes Temperature -40 25 100 °C Supply Voltage (Detector) 4.5 5.0 5.5 Volts Ripple < 100mVpp Operating Frequency

360 CPR

720 CPR

Velocity (rpm) x N/60 Shaft Radial Play Plus Eccentricity 0.05 mm TIR Shaft Axial Play ±0.100 mm

Electrical Characteristics

Electrical characteristics over recommend operating range, typical at 25°C Parameter Symbol Min. Typ. Max. Units Notes Supply Current ICC 30 45 60 mA High Level Output Voltage VOH 2.4 V Low Level Output Voltage VOL 0.4 V Rise Time tr 470 ns CL = 50pF Fall Time tf 30 ns Loading Capacitance CLOAD 50 pF

Encoding Characteristics (Channel A and B) AEDS-9240-G00 (360 CPR) Encoding characteristics over the recommended operating conditions and mounting tolerances. These characteristics include codewheel contribution. The typical values are average over the full rotation of the codewheel. Parameter Symbol Minimum Typical Maximum Units Pulse Width Error ΔP 7 35 °e Logic State Width Error ΔS 5 35 °e Phase Error Δf 2 15 °e Cycle Error ΔC 3 15 °e Position Error Δθ 5 20 min. of arc Index Pulse Width P0 120 180 240 °e AEDS-9240-Y00 (720 CPR) Encoding characteristics over the recommended operating conditions and mounting tolerances. These characteristics include codewheel contribution. The typical values are average over the full rotation of the codewheel. Parameter Symbol Minimum Typical Maximum Units Pulse Width Error ΔP 7 50 °e Logic State Width Error ΔS 5 50 °e Phase Error Δf 2 35 °e Cycle Error ΔC 15 45 °e Position Error Δθ 10 20 min. of arc Index Pulse Width P0 240 360 480 °e

Pin #1 start from left side. Pin Function 1 U 2 I 3 V 4 W

5 Ground

6 Vcc

Pin #1 Pin #8 Mating Connector Due to female connector availability, a 8 x 2 (1.27 mm x 1.27 mm) female IDC Connector is recommended. The cable used is 0.635 mm pitch flat ribbon cable. Commutation Characteristics (Channel U, V, W) Encoding characteristics over the recommended operating conditions and mounting tolerances. These characteristics include codewheel contribution. The typical values are average over the full rotation of the codewheel. Parameter Symbol Minimum Maximum Units Commutation Format Three Phase 4, 6, 8, 10 poles Commutation Accuracy (middle of channel I to channel U) ΔI -1 +1 °mechanical Commutation Accuracy (Channel U,V and W) ΔUVW -2 +2 °mechanical

  1. Dimensions in mm unless otherwise stated
  2. Linear tolerance: Up to 6mm is ± 0.15mm, Above 6mm is ± 0.5mm

Figure 1. Encoder module dimensions

Figure 4. Output waveform specification of 2 pole-pairs (4 poles) for counter clockwise rotation, viewed from the top Note: In the above waveform, quadrature signals A, B are not drawn to scale with respect to index pulse and commutation signals.

180 MECH-DEG

30 MECH-DEG

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, Limited in the United States and other countries. Data subject to change. Copyright © 2007 Avago Technologies Limited. All rights reserved. AV02-0994EN - February 20, 2008

Ordering Information

HEDS-8953 – Alignment tool for 360/720 CPR AEDS-9240 - - 00CPR G = 360 CPR Y = 720 CPR