IPD2547A OSRAM Opto Semiconductors Inc, IPD2547A Datasheet - Page 7

• Manufacturer Part Number: IPD2547A
• Description: DISPLAY 4CHAR .250" GREEN
• Manufacturer: OSRAM Opto Semiconductors Inc
• Series: Alphanumeric Programmable Display™r

Specifications of IPD2547A

• 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: Green
• Configuration: 5 x 7
• Number Of Digits: 4
• Character Size: 0.252 in
• Illumination Color: Green
• Wavelength: 568 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: Q68000A9884

Block Diagram
Functional Description
The block diagram includes 5 major blocks and internal registers
(indicated by dotted lines).
Display Memory consists of a 5 x 8 bit RAM block. Each of the
four 8-bit words holds the 7-bits of ASCII data (bits D0–D6) and an
attribute select bit (Bit D7). The fifth 8-bit memory word is used as
a control word register. A detailed description of the control regis-
ter and its functions can be found under the heading Control Word.
Each 8-bit word is addressable and can be read from or written to.
Mode Selection
Data Input Commands
2006-03-03
CEO
0
1
X
X
0=Low logic level, 1=High logic level, X=Don’t care
CEO
1
0
0
0
0
0
0
D0-D7
CE0, CE1
A0-A2
RD, WR
CLK SEL
XCLK
RST
CE1
0
1
1
1
1
1
1
8
7
3
CE1
1
X
0
X
RD
X
0
1
1
1
1
1
Display Memory
Decode
Logic
OSC
Mux
(RAM) 4 x 8
and
4
WR
X
1
0
0
0
0
0
RD
0
X
X
1
Display
3
5
A2
X
1
1
1
1
1
1
Control
1 x 8
Reg
Multiplexer
Display
A1
X
0
0
0
1
1
0
Control
Output
Logic
WR
0
X
X
1
14
8
A0
X
0
0
1
0
1
0
1
20
1
D7
X
X
0
0
0
0
1
Operation
None
None
None
None
128 Char
128 x 5
ROM
3
Column
Drivers
Drivers
Output
Latch
Row
D6
X
X
0
1
1
0
X
IDBD5065
15
20
D5
X
X
1
0
1
1
X
7
The Control Logic dictates all of the features of the display device
and is discussed in the Control Word section of this
data sheet.
The Character Generator converts the 7-bit ASCII data into the
proper dot pattern for the 128 characters shown in the character
set chart.
The Clock Source can originate either from the internal oscillator
clock or from an external source–usually from the output of
another IPD2545/7/8A in a multiple module display.
The Display Multiplexer controls all display output to the digit
drivers so no additional logic is required for a display system.
The Column Drivers are connected directly to the display.
The Display has four digits. Each of the four digits is comprised of
35 LEDs in a 5 x 7 dot array which makes up the alphanumeric
characters.
The intensity of the display can be varied by the Control Word in
steps of 0% (Blank), 25%, 50%, and full brightness.
The Reset pin when activated clears the internal counter. A reset
is usually done after power up and is of very short duration-nano-
seconds or microseconds. If the reset pin is held low for a longer
time (milliseconds) some or all LEDs in the bottom row may light
up. The appearance of lit LEDs during a “reset” is not an indication
of a malfunctioning part. It is advisable to keep the reset pulse as
short as possible to avoid displaying a row of lit LEDs.
Microprocessor Interface
The interface to the microprocessor is through the address lines.
(A0–A2), the data bus (D0–D7), two chip select lines (CE0, CE1),
and read (RD) and write (WR) lines.
The CE0 should be held low when executing a read, or write oper-
ation. CE1 must be held high.
The read and write lines are both active low. During a valid read
the data lines (D0–D7) become outputs. A valid write will enable
the data lines as inputs.
Input Buffering
If a cable length of 6 inches or more is used, all inputs to the dis-
play should be buffered with a tri-state non-inverting buffer
mounted as close to the display as conveniently possible. Recom-
mended buffers are: 74LS245 for the data lines and 74LS244 for
the control lines.
D4
X
X
0
1
0
1
X
IPD2545A, IPD2547A, IPD2548A
D3
X
X
0
0
0
0
X
D2
X
X
1
1
1
0
X
D1
X
X
0
1
1
1
X
D0
X
X
0
1
0
1
X
Operation
No Change
Read Digit 0 Data to Bus
($) Written to Digit 0
(W) Written to Digit 1
(f) Written to Digit 2
(3) Written to Digit 3
Char. Written to Digit 0
and Cursor Enabled