HDSP-2131_07 Datasheet, PDF (15/16 Pages) AVAGO TECHNOLOGIES LIMITED – Eight Character 5.0 mm (0.2 inch) Glass/Ceramic Intelligent 5x7 Alphanumeric Displays for Military Applications

antistatic packages or conductive
material. During assembly, a
grounded conductive work area
should be used, and assembly
personnel should wear conductive
wrist straps. Lab coats made of
synthetic material should be
avoided since they are prone to
static charge buildup. Input
current latchup is caused when
the CMOS inputs are subjected to
either a voltage below ground
(V_IN < ground) or to a voltage
higher than V_DD (V_IN > V_DD) and
when a high current is forced into
the input. To prevent input cur-
rent latchup and ESD damage,
unused inputs should be con-
nected either to ground or to V_DD.
Voltages should not be applied to
the inputs until V_DD has been
applied to the display. Transient
input voltages should be eliminated.
Thermal Considerations
The HDSP-213x/-2179 has been
designed to provide a low thermal
resistance path from the CMOS IC
to the 24 package pins. This heat is
then typically conducted through
the traces of the user’s printed
circuit board to free air. For most
applications no additional
heatsinking is required.
The maximum operating IC
junction temperature is 150°C.
The maximum IC junction tem-
perature can be calculated using
the following equation:
Ground Connections
Two ground pins are provided to
keep the internal IC logic ground
clean. The designer can, when
necessary, route the analog
ground for the LED drivers sep-
arately from the logic ground until
an appropriate ground plane is
available. On long interconnects
between the display and the host
system, the designer can keep
voltage drops on the analog
ground from affecting the display
logic levels by isolating the two
grounds.
The logic ground should be con-
nected to the same ground poten-
tial as the logic interface circuitry.
The analog ground and the logic
ground should be connected at a
common ground which can
withstand the current introduced
by the switching LED drivers.
When separate ground connec-
tions are used, the analog ground
can vary from -0.3 V to +0.3 V
with respect to the logic ground.
Voltage below -0.3 V can cause all
dots to be on. Voltage above +0.3
V can cause dimming and dot
mismatch.
ESD Susceptibility
These displays have ESD sus-
ceptibility ratings of CLASS 3 per
DOD-STD-1686 and CLASS B per
MIL-STD-883C.
Soldering and Post Solder
Cleaning Instructions for the
HDSP-213x/-2179
The HDSP-213x/-2179 may be
hand soldered or wave soldered
with lead-free solder. When hand
soldering it is recommended that
an electronically temperature con-
trolled and securely grounded
soldering iron be used. For best
results, the iron tip temperature
should be set at 315°C (600°F).
For wave soldering, a rosin-based
RMA flux can be used. The solder
wave temperature should be set at
245°C ± 5°C (473°F ± 9°F), and
dwell in the wave should be set
between 1¹/₂ to 3 seconds for
optimum soldering. The preheat
temperature should not exceed
105°C (221°F) as measured on
the solder side of the PC board.
Proper handling is imperative to
avoid excessive thermal stresses
to component when heated.
Therefore, the solder PCB must be
allowed to cool to room
temperature, 25°C, before
handling.
For further information on
soldering and post solder
cleaning, see Application Note
1027, Soldering LED Components.
T_J(IC) MAX = T_A
+ (P_DMAX) (Rq_J-PIN + Rq_PIN-A)
Where
P_DMAX = (V_DDMAX) (I_DDMAX)
I_DDMAX = 370 mA with 20 dots
ON in eight character locations at
25°C ambient. This value is from
the Electrical Characteristics
table.
P_DMAX = (5.5 V) (0.370 A)
= 2.04 W
TURBULENT WAVE
250
200
150
FLUXING
100
LAMINAR WAVE
HOT AIR KNIFE
BOTTOM SIDE
OF PC BOARD
TOP SIDE OF
PC BOARD
CONVEYOR SPEED = 1.83 M/MIN (6 FT/MIN)
PREHEAT SETTING = 150°C (100°C PCB)
SOLDER WAVE TEMPERATURE = 245°C
AIR KNIFE AIR TEMPERATURE = 390°C
AIR KNIFE DISTANCE = 1.91 mm (0.25 IN.)
AIR KNIFE ANGLE = 40°
50
30
PREHEAT
NOTE: ALLOW FOR BOARDS TO BE
SUFFICIENTLY COOLED BEFORE
EXERTING MECHANICAL FORCE.
0 10 20 30 40 50 60 70 80 90 100
TIME – SECONDS
Figure 9. Recommended wave soldering profile for lead-free Smart Display.
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