HEDR-8130 Datasheet, PDF (1/8 Pages) Agilent(Hewlett-Packard) – Reflective Optical Surface Mount Encoders

Agilent HEDR-8130
Reflective Optical Surface
Mount Encoders
Data Sheet
Description
The HEDR-8130 encoder uses
reflective technology to sense
rotary or linear position. This sen-
sor consists of an LED light source
and a photodetector IC in a single
S0-8 surface mount package. When
used with a reflective codewheel or
codestrip, this device can sense
rotary or linear position.
The reflective surface mount opti-
cal encoder provides two square
wave outputs in quadrature for
count and direction information.
These TTL-compatible outputs
correspond to the alternating re-
flective/non-reflective pattern of
the codewheel or codestrip.
The HEDR-8130 can be used with
a codewheel or codestrip with 150
lines per inch (5.91 lines per mm).
Applications
The HEDR-8130 provides two
channel motion sensing at a very
low cost, making it ideal for high
volume applications. Its small size
and surface mount capability make
it ideal for printers, copiers, card
readers, and consumer product
applications.
Note: Agilent Technologies
encoders are not recommended
for use in safety critical
applications. Eg. ABS braking
systems, power steering, life
support systems and critical care
medical equipment. Please
contact sales representative if
more clarification is needed.
Features
• Reflective technology
• Surface mount S0-8 package
• Two channel quadrature outputs
for direction sensing
• 3.3 V input and output
• 150 lpi (5.91 lines/mm)
Theory of Operation
The HEDR-8130 combines an
emitter and a detector in a single
surface mount S0-8 package.
When used with a codewheel or
codestrip, the reflective sensors
translate rotary or linear motion
into a two-channel digital output.
The HEDR-8130 has three key
parts: a single Light Emitting
Diode (LED) light source, a
photodetector IC with a set of
uniquely configured photodiodes,
and a pair of lenses molded into
the package. The lens over the
LED focuses light onto the
codewheel or codestrip. Light is
either reflected or not reflected
back to the lens over the photo-
detector IC.
As the codewheel rotates, or
codestrip passes by, an alternat-
ing pattern of light and dark cor-
responding to the pattern of the
codewheel falls upon the photo-
diodes. This light is used to pro-
duce internal signals A and A-bar,
and B and B-bar. As part of this
“push-pull” detector system,
these signals are fed through
comparators to produce the final
output for channels A and B.
ESD WARNING: NORMAL HANDLING PRECAUTIONS SHOULD BE TAKEN TO AVOID STATIC DISCHARGE.