2–5
DLR/DLO/DLG1414
For further information refer to Appnotes 18 and 19 in the cur-
rent Siemens Optoelectronic Data Book.
An alternative to soldering and cleaning the display modules is
to use sockets. Eighteen pin DIP sockets .600" wide with .100"
centers work well for single displays. Multiple display assem-
blies are best handled by longer SIP sockets or DIP sockets
when available for uniform package alignment. Socket manu-
facturers are Aries Electronics, Inc., Frenchtown, NJ; Garry
Manufacturing, New Brunswick, NJ; Robinson-Nugent, New
Albany, IN; and Samtec Electronic Hardware, New Albany, IN.
For further information refer to Appnote 22 in the current Sie-
mens Optoelectronic Data Book.
Optical Considerations
The .145" high characters of the DLX1414 gives readability up
to eight feet. The user can build a display that enhances read-
ability over this distance by proper filter selection .
Using filters emphasizes the contrast ratio between a lit LED
and the character background. This will increase the discrimi-
nation of different characters. The only limitation is cost.
Remember to take into consideration the ambient lighting envi-
ronment for the best cost/benefit ratio for filters.
Incandescent (with almost no green) or fluor escent (with almost
no red) lights do not have the flat spectral r esponse of sunlight.
Plastic band-pass filters are an inexpensive and effective way
to strengthen contrast ratios. The DLR1414 is a standard red
display and should be matched with long wavelength pass fil-
ter in the 600 nm to 620 nm range. For displays of multiple col-
ors, neutral density grey filters offer the best compromise.
The DLO1414 is a high efficiency red display and should be
matched with a long wavelength pass filter in the 570 nm to 590
range. The DLG1414 should be matched with a yellow-green
band-pass filter that peaks at 565 nm. For displays of multiple
colors, neutral density gray filters offer the best compromise.
Additional contrast enhancement can be gained by shading
the displays. Plastic band-pass filters with built-in louvers offer
the next step up in contrast improvement. Plastic filters can be
improved further with anti-reflective coatings to reduce glare.
The trade-off is fuzzy characters. Mounting the filters close to
the display reduces this effect. Take care not to overheat the
plastic filter by allowing for proper air flow.
Optimal filter enhancements are gained by using circular polar-
ized, anti-reflective, band-pass filters. The circular polarizing
further enhances contrast by reducing the light that travels
through the filter and reflects back off the display to less
than 1%.
Several filter manufacturers supply quality filter materials.
Some of them are: Panelgraphic Corporation, W. Caldwell, NJ;
SGL Homalite, Wilmington, DE; 3M Company, Visual Products
Division, St. Paul, MN; Polaroid Corporation, Polarizer Division,
Cambridge, MA; Marks Polarized Corporation, Deer Park, NY,
Hoya Optics, Inc., Fremont, CA.
One last note on mounting filters: recessing displays and bezel
assemblies is an inexpensive way to provide a shading ef fect in
overhead lighting situations. Several bezel manufacturers are:
R.M.F. Products, Batavia, IL; Nobex Components, Griffith Plas-
tic Corp., Burlingame, CA; Photo Chemical Products of Califor-
nia, Santa Monica, CA; I.E.E.-Atlas, Van Nuys, CA.
Refer to Siemens Appnote 23 for further information.
Design Considerations
For details on design and applications of the DLX1414 using
standard bus configurations in multiple display systems, or
parallel I/O devices, such as the 8255 with an 8080 or mem-
ory mapped addressing on processors such as the 8080,
Z80, 6502, 8748, or 6800, refer to Appnote 15 in the current
Siemens Optoelectronic Data Book.
Electrical & Mechanical Considerations
V oltage Transient Suppression
We str ongly recommend that the same power supply be used
for the display and the components that interface with the dis-
play to avoid logic inputs higher than V
CC
. Additionally, the
LEDs may cause transients in the power supply line while
they change display states. The common practice is to place
.01 mF capacitors close to the displays across V
CC
and GND,
one for each display, and one 10 mF capacitor for every sec-
ond display.
ESD Protection
The metal gate CMOS IC of the DLX1414 is extremely
immune to ESD damage. However, users of these devices are
encouraged to take all the standard precautions, normal for
CMOS components. These include properly grounding per-
sonnel, tools, tables, and transport carriers that come in con-
tact with unshielded parts. Where these conditions are not, or
cannot be met, keep the leads of the device shorted together
or the parts in anti-static packaging.
Soldering Considerations
The DLX1414 can be hand soldered with SN63 solder using a
grounded iron set to 260
°
C.
Wave soldering is also possible following these conditions:
Preheat that does not exceed 93
°
C on the solder side of the
PC board or a package surface temperature of 85
°
C. Water
soluble organic acid flux (except carboxylic acid) or resin-
based RMA flux without alcohol can be used.
Wave temperature of 245
°
C
±
5
°
C with a dwell between 1.5
sec. to 3.0 sec. Exposure to the wave should not exceed tem-
peratures above 260
°
C for five seconds at 0.063" below the
seating plane. The packages should not be immersed in the
wave.
Post Solder Cleaning Procedures
The least offensive cleaning solution is hot D.I. water (60
°
C)
for less than 15 minutes. Addition of mild saponifiers is
acceptable. Do not use commercial dishwasher detergents.
For faster cleaning, solvents may be used. Carefully select
solvents as some may chemically attack the nylon package.
Maximum exposure should not exceed two minutes at ele-
vated temperatures. Acceptable solvents are TF (trichlorotrif-
luorethane), TA, 111 Trichloroethane, and unheated acetone.
Note: Acceptable commercial solvents are: Basic TF, Arklone P,
Genesolve D, Blaco-tron TF, Freon TA, Genesolve DA, and
Blaco-tron TA.
Unacceptable solvents contain alcohol, methanol, methylene
chloride, ethanol, TP35, TCM, TMC, TMS+, TE, or TES. Since
many commercial mixtur es exist, contact a solvent vendor for
chemical composition information. Some major solvent man-
ufacturers ar e: Allied Chemical Corporation, Specialty Chem-
ical Division, Morristown, NJ; Baron-Blakeslee, Chicago, IL;
Dow Chemical, Midland, MI; E.I. DuPont de Nemours & Co.,
Wilmington, DE.