HEDS-9202 Datasheet, PDF (1/7 Pages) AVAGO TECHNOLOGIES LIMITED – Two Channel Optical Incremental Encoder Modules 200 LPI Analog Output

HEDS-9202
Two Channel Optical Incremental Encoder
Modules 200 LPI Analog Output
Data Sheet
Description
The HEDS-9202 is a high-performance, low-cost, op-
tical incremental encoder module. When operated in
conjunction with either a codewheel or codestrip, this
module detects rotary or linear position. The encoder
module consists of a lensed LED source and a detector
IC enclosed in a small C-shaped plastic package. Due
to a highly collimated light source and a unique photo-
detector array, the module is extremely tolerant to
mounting misalignment.
The two channel analog outputs and 5 V supply input
are accessed through five 0.025 inch square pins
located on 0.1 inch centers. The standard HEDS-9202
is designed for use with an appropriate optical
radius codewheel, or linear codestrip.
Features
• Low cost
• Multiple mounting options
• 200 lpi resolution
• Linear and rotary options available
• No signal adjustment required
• Insensitive to radial and axial play
• –10°C to 100°C operating temperature
• Two channel analog output
• Single 5 V supply
• Wave solderable
Applications
The HEDS-9202 provides sophisticated motion detec-
tion at a low cost, making closed-loop control very
cost-effective. Typical applications include printers,
plotters, copiers, and office automation equipment.
Note: Avago Technologies’ encoders are not recom-
mended for use in safety critical applications, e.g., ABS
braking systems, power steering, life support systems,
and critical care medical equipment. Please contact
sales representatives if more clarification is needed.
Theory of Operation
The HEDS-9202 is a C-shaped emitter/detector mod-
ule. Coupled with a codewheel, it translates rotary
motion into a two-channel analog output. Coupled
with a codestrip, it translates linear motion into analog
outputs. The module contains a single Light Emitting
Diode (LED) as its light source. The light is collimated
into a parallel beam by means of a single lens located
directly over the LED. Opposite the emitter is the
integrated detector circuit. This IC consists of multiple
sets of photodetectors and the signal processing cir-
cuitry necessary to produce the analog waveforms.
The codewheel/codestrip moves between the emitter
and detector, causing the light beam to be interrupted
by the pattern of spaces and bars on the codewheel/
codestrip. The photodiodes which detect these inter-
ruptions are arranged in a pattern that corresponds to
the radius and count density of the codewheel/codestrip.
These detectors are also spaced such that a light p e -
riod on one pair of detectors corresponds to a dark
period on the adjacent pair of detectors. The photo-
diode outputs are fed through the signal processing