IPD2548A OSRAM Opto Semiconductors Inc, IPD2548A Datasheet - Page 9

• Manufacturer Part Number: IPD2548A
• Description: DISPLAY 4CHAR .250" YELLOW
• Manufacturer: OSRAM Opto Semiconductors Inc
• Series: Alphanumeric Programmable Display™r

Specifications of IPD2548A

• Millicandela Rating: 150µcd
• Size / Dimension: 1.20" L x 0.49" W x 0.17" H (30.48mm x 12.45mm x 4.32mm)
• Color: Yellow
• Configuration: 5 x 7
• Number Of Digits: 4
• Character Size: 0.252 in
• Illumination Color: Yellow
• Wavelength: 585 nm
• Maximum Operating Temperature: + 100 C
• Minimum Operating Temperature: - 55 C
• Luminous Intensity: 150 ucd
• Viewing Area (w X H): 4.32 mm x 6.4 mm
• Display Type: 5 x 7 Dot Matrix
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Forward (vf) Typ: -
• Internal Connection: -
• Lead Free Status / Rohs Status: Details
• Other names: Q68000A9885

*“Cursor”= all dots in a single character space lit to half brightness
X = don't care
B = depends on the selected brightness
Attributes are non-destructive. If a character with bit D7 set is
replaced by a cursor (Control Word bit D4 is set, and D3=D2=0)
the character will remain in memory and can be revealed again by
clearing D4 in the Control Word.
Blink (D5): The entire display can be caused to blink at a rate of
approximately 2.0 Hz by setting bit D5 in the Control Word. This blink-
ing is independent of the state of D7 in all character locations.
To synchronize the blink rate in a bank of these devices, it is nec-
essary to tie all devices' clocks and resets together as described in
a later section of this data sheet.
Lamp Test (D6): When the Lamp Test bit is set, all dots in the
entire display are lit at half brightness. When this bit is cleared, the
display returns to the characters that were showing before the
lamp test.
Cascading the Display
2006-03-03
D7 D6 D5 D4 D3 D2 D1 D0 Operation
0
0
0
0
0
D7 D6 D5 D4 D3 D2 D1 D0 Operation
0
0
0
0
0
0
0
RESET
D0-D7
A0-A2
WR
RD
10 µF
0
0
0
0
0
1
A3
A4
A5
0.01 µF
0
1
1
1
1
X
V
X
0
0
1
1
X
CC
1
2
3
6
74LS138
4
X
0
1
0
1
X
8
16
5
12
13
14
15
V
CC
B
B
B
B
B
B
B
B
B
B
B
B
Disable highlight
attribute
Display cursor*
instead of character
Blink single character
Display blinking cur-
sor* instead of char-
acter
Alternate character
with cursor*
Blinking display
0.01 µF
9
Clear Data (D7): When D7 (D7=1) is set in the Control Word, all
display memory bits are reset to zero. A second Control Word must
be written into the chip with D7 (D7=0) reset to set up attributes and
brightness levels.
Cascading
Cascading the display (Figure below) is a simple operation. The
requirements for cascading are:
1) decoding the correct address to determine the chip select for
each additional device,
2) assuring that all devices are reset simultaneously, and
3) selecting one display as the clock source and setting all others
to accept clock input (the reason for cascading the clock is to syn-
chronize the flashing of multiple displays). One display as a source
is capable of driving six other displays. If more displays are
required, a buffer will be necessary. The source display must have
pin 3 tied high to output clock signals. All other displays must have
pin 3 tied low.
Voltage Transients
It has become common practice to provide 0.01 µF bypass capaci-
tors liberally in digital systems. Like other CMOS circuitry, the Intel-
ligent Display controller chip has very low power consumption and
the usual 0.01 µF would be adequate were it not for the LEDs. To
prevent power supply transients, capacitors with low inductance
and high capacitance at high frequencies are required. This sug-
gests a solid tantalum or ceramic disc for high frequency bypass.
For larger displays, distribute the bypass capacitors evenly, keep-
ing capacitors as close to the power pins as possible. We recom-
mend a 10 µF and 0.01 µF for every Intelligent Display to decouple
the displays themselves, at the display.
10 µF
D7 D6 D5 D4 D3 D2 D1 D0 Operation
0
D7 D6 D5 D4 D3 D2 D1 D0 Operation
1
1
0
0.01 µF
IPD2545A, IPD2547A, IPD2548A
0
X
0
X
X
X
X
X
X
X
0.01 µF
X
X
Lamp test
Clear
IDCD5039