HOA0902DESCRIPTIONFEATURES· Dual channel IC· Direct TTL interface· Resolution to 0.018 in.(.457)· Internal temperature compensation· 0.126 in.(3.2 mm) slot width· Two mounting configurationsThe HOA0902 assembly consists of a dual channel ICdetector and an IRED encased in a black thermoplastichousing. The device is typically used with an interrupterstrip or disk (code wheel) to encode the rate anddirection of mechanical motion. Applications includelinear and rotary encoders; it is especially suited for theencoding function in an optical mouse.The detector is a monolithic IC which consists of twonarrow adjacent photodiodes, amplifiers stages andquadrature logic circuitry which provides two outputs;(1) a fixed-duration, low level active tachometer(counting) pulse which is generated whenever theillumination level passes through the sensing threshold,and (2) a direction output which is set to a logic high orlow level dependent on which of the two channels isilluminated first. The tachometer output is an NPNcollector which is internally connected to Vùù through a10 kì (nominal) resistor; the direction output is a totempoleconfiguration. Both outputs are capable of directlydriving TTL loads. The IC design incorporates circuitryto compensate the sensitivity for the output power vs.temperature characteristic of the IRED.The tachometer pulse is generated at both theincreasing and decreasing illumination thresholds of thesensing channel, resulting in two tach pulses for eachmechanical period of the interrupter. The HOA0902 isdesigned to work with a mechanical period as small as0.036 in.(.914 mm), providing resolution to 0.018in.(.457 mm). For additional component information seeSEP8506 and HLC2705.Housing material is polycarbonate. Housings aresoluble in chlorinated hydrocarbons and ketones.Recommended cleaning agents are methanol andisopropanol.OUTLINE DIMENSIONS in inches (mm)Tolerance 3 plc decimals ±0.005(0.12)2 plc decimals ±0.020(0.51).419(10.64) .020(0.51)LEADS TYP.SQ..05(1.27)3 PLCS.181(4.60).126(3.20).300(7.62).500(12.7) MIN.100(2.54)OPTICALCL.050.075(1.91)1 234 65.100(2.54)S E.315(8.0).488(12.40)LEADS1. CATHODE2. ANODE3. SPEED4. GND5. Vcc6. DIRECTION.090(2.3).083(2.1)DIM_4HOA0902-011DIM_HOA0902-012Honeywell