HDSP-076X Datasheet, PDF (5/8 Pages) Agilent(Hewlett-Packard) – Hexadecimal and Numeric Displays for Industrial Applications

5
Operational
Considerations
Electrical
These devices use a modified
4 x 7 dot matrix light emitting
diode to display decimal/hexa-
decimal numeric information. The
high efficiency red and yellow
LEDs are GaAsP epitaxial layer
on a GaP transparent substrate.
The green LEDs are GaP epitaxial
layer on a GaP transparent
substrate. The LEDs are driven
by constant current drivers, BCD
information is accepted by the
display memory when the enable
line is at logic low and the data is
latched when the enable is at
logic high. Using the enable pulse
width and data setup and hold
times listed in the Recommended
Operating Conditions allows data
to be clocked into an array of
displays at a 6.7 MHz rate.
The decimal point input is active
low true and this data is latched
into the display memory in the
same fashion as the BCD data.
The decimal point LED is driven
by the on-board IC.
The blanking control input on the
hexadecimal displays blanks (turns
off) the displayed information
without disturbing the contents of
display memory. The display is
blanked at a minimum threshold
level of 2.0 volts. When blanked,
the display standby power is
nominally 250 mW at T_A = 25°C.
Mechanical
The primary thermal path for
power dissipation is through the
device leads. Therefore, to insure
reliable operation up to an
ambient temperature of +85°C, it
is important to maintain a case-
to-ambient thermal resistance of
less than 35°C watt/device as
measured on top of display pin 3.
For information on soldering and
post solder cleaning see Applica-
tion Note 1027, Soldering LED
Components.
Contrast Enhancement
These display devices are
designed to provide an optimum
ON/OFF contrast when placed
behind an appropriate contrast
enhancement filter. For further
information, please refer to
Application Note 1015, Contrast
Enhancement Techniques for
LED Displays.
Over Range Display
The over range devices display
“± 1” and decimal point. The
character height and package
configuration are the same as the
numeric and hexadecimal
devices. Character selection is
obtained via external switching
transistors and current limiting
resistors.
Package Dimensions
NOTE: 1. DIMENSIONS IN MILLIMETRES AND (INCHES).
Character
+
-
1
Decimal Point
Blank
Pin
1 2,3 4 8
1 XX1
0 XX1
X 1XX
X X1X
0 000
Notes:
0: Line switching transistor in Figure 7 cutoff.
1: Line switching transistor in Figure 7 saturated.
X: 'don't care'