HLC2705

HLC2705 Encoder Detector FEATURES Side-looking plastic package TTL/LSTTL/CMOS compatible On-chip quadrature logic which provides tach and direction outputs Linear or rotary encoder applications Resolution to 0.018 in.(.457) Sensitivity versus temperature compensation Mechanically and spectrally matched to SEP8506 and SEP8706 infrared emitting diodes INFRA-74.TIF DESCRIPTION The HLC2705 detector is designed to sense speed and direction of mechanical motion. Applications include rotary and linear encoders; the device is especially well suited for the encoding function in an optical mouse. The detector is a monolithic IC, consisting of two narrow adjacent photodiodes, amplifier stages, and quadrature logic which provides two outputs. One is a fixed duration, low level active tachometer (counting) pulse. It is generated whenever the "A" channel illumination passes through the threshold level. The second is a direction output which is set to a logic high or a logic low depending upon which channel is illuminated first. The sensor also has sensitivity compensation circuitry for the output power versus temperature characteristic of an IRED. The IC is encapsulated in a molded, unlensed black plastic package which is transmissive to IR energy, yet provides shielding from visible light. The tachometer output is an NPN collector, internally connected to VÙÙ through a 10 kì (nominal) resistor. The direction output is a totem-pole configuration. Both are capable of direct...