HDSP-2301 HP [Agilent(Hewlett-Packard)], HDSP-2301 Datasheet - Page 7

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

is loaded into the 7 on-board shift
register locations 1 through 7.
Column 1 data for digits 3, 2, and
1 is similarly shifted into the
display shift register locations.
The column 1 input is now
enabled for an appropriate period
of time, T. A similar process is
repeated for columns 2, 3, 4, and
5. If the time necessary to decode
and load data into the shift
register is t, then with five
columns, each column of the
display is operating at a duty
factor of:
The time frame, t + T, allotted to
each column of the display is
generally chosen to provide the
maximum duty factor consistent
with the minimum refresh rate
necessary to achieve a flicker free
display. For most strobed display
systems, each column of the
display should be refreshed
(turned on) at a minimum rate of
100 times per second.
With columns to be addressed,
this refresh rate then gives a
value for the time t + T of:
If the device is operated at 3.0
MHz clock rate maximum, it is
possible to maintain t << T. For
short display strings, the duty
factor will then approach 20%.
For further applications
information, refer to Agilent
Application Note 1016.
1/[5 x (100)] = 2 msec
D.F. =
5 (t + T)
T
Mechanical and Thermal
Considerations
The HDSP-2301/-2302/-2303 are
available in standard ceramic
dual-in-line packages. They are
designed for plugging into
sockets or soldering into PC
boards. The packages may be
horizontally or vertically stacked
for character arrays of any
desired size. The HDSP-2301/-
2302/-2303 utilize a high output
current IC to provide excellent
readability in bright ambient
lighting. Full power operation
(V
= 3.5 V) with worst case thermal
resistance from IC junction to
ambient of 60˚C/watt/device is
possible up to ambient
temperature of 37˚C. For
operation above 37˚C, the
maximum device dissipation
should be derated linearly at 16.7
mW/˚C (see Figure 2). With an
improved thermal design,
operation at higher ambient
temperatures without derating is
possible.
Power derating for this family of
displays can be achieved in
several ways. The power supply
voltage can be lowered to a
minimum of 4.75 V. Column
Input Voltage, V
decreased to the recommended
minimum value of 2.75 V for the
HDSP-2301/-2302/-2303. Also,
the average drive current can be
decreased through pulse width
modulation of V
CC
= 5.25 V, V
B
COL
B
.
= 2.4 V, V
, can be
COL
7
The HDSP-2301/-2302/-2303
displays have glass windows. A
front panel contrast enhancement
filter is desirable in most actual
display applications. Some
suggested filter materials are
provided in Figure 6. Additional
information on filtering and
contrast enhancement can be
found in Agilent Application
Note 1015.
For more information on
soldering and post-solder
cleaning, please see Application
Note 1027, Soldering LED
Components.