HDSP-2301 HP [Agilent(Hewlett-Packard)], HDSP-2301 Datasheet - Page 9

• Manufacturer Part Number: HDSP-2301
• Description: Four Character 5.0 mm (0.20 inch) 5 x 7 Alphanumeric Displays
• Manufacturer: HP [Agilent(Hewlett-Packard)]

Using the HDSP-2000
Alphanumeric Display Family
Application Note 1016
Introduction
First introduced in 1975, the
HDSP-2000 alphanumeric display
has been designed into a variety
of applications. The HDSP-2000
display was originally designed
for commercial, industrial, instru-
mentation, and business
equipment applications. However,
the introduction of high efficiency
red, yellow, and high performance
green devices as well as several
display sizes has opened up a mul-
titude of new applications for the
HDSP-2000 alphanumeric display
family. The high efficiency red,
yellow, and high performance
green devices use gallium phos-
phide (GaP) LEDs. The GaP
displays are readable in direct
sunlight with proper contrast en-
hancement techniques. For this
reason, the HDSP-2000 family dis-
plays have been designed into a
variety of avionic and process
control applications. The
HDSP-2000 family displays are
available in three character sizes
of 3.8 mm (0.15"), 4.9 mm (0.19"),
and 6.9 mm (0.27") to allow the
designer to optimize display com-
pactness versus long distance
readability. Versions of the
HDSP-2000 family alphanumeric
displays are available with a true
hermetic package and an operat-
ing temperature range of –55 C to
+85 C to allow designers to utilize
the proven reliability of LED dis-
play technology in military and
aerospace applications.
This note is intended to serve as a
design and application guide for
users of the HDSP-2000 family of
alphanumeric display devices.
The information presented will
cover: the theory of the device
design and operation; consider-
ations for specific circuit designs;
thermal management, power de-
rating and heat sinking; intensity
modulation techniques.
The HDSP-2000 family has been
designed to provide a high resolu-
tion information display
subsystem. Each character of the
4 character package consists of a
5 x 7 array of LEDs which can dis-
play a full range of alphabetic and
numeric characters plus punctua-
tion, mathematical and other
special symbols. The HDSP-2000
family is available in four colors:
red, high efficiency red, yellow,
and high performance green.
The character height, character
spacing, color and part number of
each member of the HDSP-2000
family of displays is shown in
Table 1. The overall package size
is designed to allow end stacking
of multiple clusters to form char-
acter strings of any desired
length.
Electrical Description
The on-board electronics of the
HDSP-2000 display family elimi-
nates some of the classical
difficulties associated with the
use of alphanumeric displays. Tra-
ditionally, single digit LED dot
matrix displays have been orga-
nized in an x-y addressable array
requiring 12 interconnect pins per
digit plus extensive row and col-
umn drive support electronics. All
members of the HDSP-2000 dis-
play family provide on-board
storage of decoded row data plus
constant current sinking row driv-
ers for each of the 28 rows in the
4 character display. This approach
allows the user to address each
display package through just 11
active interconnections vs. the
176 interconnections and 36 com-
ponents required to effect a
similar function using conven-
tional LED matrices.
Figure 1 is a block diagram of the
internal circuitry of the
HDSP-2000 display. The device
consists of four LED matrices and