AEDB-9340 Series 1250/2500 CPR Commutation Encoder Modules with Codewheel Data Sheet Description Features The AEDB-9340 optical encoder series are six-channel Two-channel quadrature output with ungated index optical incremental encoder modules with codewheel. pulse (A, B, I) The encoder is compliant to RoHS directive and had Three-channel integrated commutation output (U, V, W) been declared as a lead free product. When used with Up to 2500 Cycles Per Revolution (CPR) codewheel, these modules detect rotary position. Each Easy assembly with alignment jig module consists of a collimated LED source and detector IC enclosed within a small plastic package. Due to Designed to fit into circular shaped housing highly collimated light source and unique photo detec- Up to 150 kHz frequency response tor array designs, these modules are extremely tolerant 10C to 85C operating temperature to mounting misalignment. TTL compatible The AEDB-9340 optical encoder has integrated commu- Single 5 V supply tation output (U, V, W), two-channel quadrature outputs plus a third channel index output (A, B, I). This ungated Integrated feedback device for Brushless DC Motor index output is a positive index pulse that is generated once for each full rotation of the codewheel. The AEDB-9340 series optical encoder is designed for Applications use with a codewheel that has an optical radius of Typical applications include industrial printers, plotters, 15 mm (0.590 inch) for 1250/2500 CPR, 12.3 mm (0.484 tape drives, and industrial and factory automation inch) for 1024/2048 CPR and 12 mm (0.472 inch) for 1000/ equipment. 2000 CPR. Note: Avago Technologies encoders are not recommended The quadrature, index, commutation signals and power for use in safety critical applications, e.g., ABS braking supplied to encoder are accessed through eight systems, power steering, life support systems and critical 0.46 mm square male connector pins located on 1.27 mm care medical equipment. Please contact sales representative if more clarification is needed. (pitch). The AEDB-9340 optical encoder provides advanced motion control detection with integrated commutation outputs (U, V, and W). It is equivalent to those produced by Hall Switches, thus making it ideal for servo motor application. With the AEDB-9340 solution, the system will be more compact, have reduced alignment time with usage of alignment jig, thus making assembly process much easier for housed encoder integration. It has superior switching accuracy due to much lower hysteresis when compared to a Hall Switches. The com- mutation signals can be generated for Brushless DC motor of different rotor pole-pairs by simply changing with matching pole-pair codewheel.Theory of Operation Cycle Error (DC): An indication of cycle uniformity. The difference between an observed shaft angle which gives The AEDB-9340 optical encoder is a emitter-detector rise to one electrical cycle, and the nominal angular module. Coupled with codewheel, these modules trans- increment of 1/N of a revolution. late the rotary motion of a shaft into six-channel digital output. Pulse Width (P): The number of electrical degrees that an output is high during 1 cycle. This value is nominally The modules contain a single Light Emitting Diode 180e or 1/2 cycle. (LED) as light source. The light is collimated into a parallel beam by means polycarbonate lens located Pulse Width Error (D P): The deviation, in electrical directly over the LED. Opposite the emitter is a detector degrees, of the pulse width from its ideal value of 180e. IC. This IC consists of multiple sets of photo detectors and signal processing circuitry necessary to produce State Width (S): The numbers of electrical degrees digital waveforms output. between transitions in the output of channel A and the neighboring transition in the output of channel B. There The codewheel rotates between the emitter and detec- are 4 states per cycle, each nominally 90e. tor, causing the light beam to be interrupted by pattern of spaces and bars on the codewheel. State Width Error (D S): The deviation, in electrical degrees, of each state width from its ideal value of 90e. The Photodiodes that detect these interruptions are arranged in a pattern that corresponds to the radius Commutation Accuracy (D I): The deviation, in and design of the codewheel. These detectors are also mechanical degrees, after shaft rotates passing the spaced in such away that light period on one pair of reference point (Index channel) to the first Channel-U detectors corresponds to dark period on adjacent pair pulse. The measurement from middle of Channel-I to of detectors. rising edge of Channel-U. The photodiode outputs are then fed through the signal Phase (f): The numbers of electrical degrees between processing circuitry resulting in A, A, B, B, I, and I. the center of the high state of channel A and the center Comparators receive these signals and produce the final of the high state of channel B. This value is nominally outputs for channels A and B. Due to this integrated 90e for quadrature output. phasing technique, the digital output of channel A is This value is nominally 90e for quadrature output. in quadrature with that of channel B (90 degrees out of phase). The commutation feedback (U, V, W) signals Phase Error (Df ): The deviation of the phase from its are generated based on the codewheel design. ideal value of 90e. Direction of Rotation: When the codewheel rotates in Definitions the clockwise direction viewing from top of the Cycles (N): The number of electrical cycles per module (direction from pin U to B), channel A will lead revolution (CPR). Note: CPR refers to the raw signal from channel B. If the codewheel rotates in the opposite encoder, that is the cycles before 4x decode. direction (direction from pin B to U), channel B will lead channel A. One Cycle: 360 electrical degrees (e). Optical Radius (Rop): The distance from the One Shaft Rotation: 360 mechanical degrees. codewheels 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 with reference to channel A or channel B during one full shaft rotation. 2