AEDR-871x 3-Channel High Resolution Reflective Incremental Encoder (Digital Outputs) Data Sheet Description Features The AEDR-871x encoder is the smallest 3-channel opti- World s smallest 3-channel reflective technology cal encoder with digital outputs that employs Reflective encoder Technology for motion control. Digital Output option - 3 channels TTL compatible 2 channel quadrature (AB) digital outputs for direction The encoder is designed to operate over the -20 C to 85 sensing and a third channel, Index digital output. Built- C temperature range and so is suitable for both commer- in interpolator for 4, 8 and 16 interpolation. cial and industrial applications. Surface mount leadless package 3.95 mm (L) 3.4 mm AEDR-871x offers high resolution (318 LPI) with built-in (W) 0.9562 mm (H) interpolation, enabling great flexibility and versatility in resolution range. Operating voltage of 3.3 V or 5 V supply Built-in LED current regulation, removing need for The compact dimensions of 3.95 mm (L) 3.4 mm (W) external biasing resistor 0.9562 mm (H) coupled with the low operating 3.3 V op- tion allows it to be used in a wide range of miniature com- -20 C to 85 C absolute operating temperature mercial applications and portable devices in which space Encoding resolution: 318 (lines/inch, LPI) and power consumption is a primary concern. Applications AEDR-871x encoder offers two-channel (AB) quadrature digital outputs and a third channel, index digital outputs. Ideal for high volume applications: Being TTL compatible, the outputs of the AEDR-871x en- Miniature motors coder can be interfaced directly with most of the signal processing circuitries. Therefore, the encoder provides Printers and copiers great design-in flexibility and easy integration into exist - Card readers ing systems. Miniature camera module Portable measurement devices Healthcare, lab diagnostic equipment and portable devices Optometric equipment Consumer and industrial product applicationsOutput Waveform Top View C P 360 e Deg A S1 S2 S3 S4 B Anti-clockwise Po Index of 90 e Deg option CH A leads I Encoder 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 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 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) P The number of electrical degrees that an output is high during 1 cycle. This value is nominally 180e or 1/2 cycle. Pulse Width (Duty) Error P The deviation, in electrical degrees, of the pulse width from its ideal value of 180e. 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 90e. State Error S The deviation, in electrical degrees, of each state width from its ideal value of 90e. 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 90e for quadrature output. Phase Error The deviation of the phase from its ideal value of 90e. Optical Radius R The distance from the codewheels center of rotation to the optical center (O.C.) of the en- OP coder module. Index Pulse Width P The number of electrical degrees that an index is high during one full shaft rotation. O 2 Amplitude