Semiconductor
ML9471
1/3, 1/4, 1/5 Duty 80 Output LCD Driver
FEDL9471-01
Issue Date: Aug. 21, 2008
GENERAL DESCRIPTION
The ML9471 is a LCD driver for dynamic display providing 3-duty-switchable pins (1/3, 1/4, 1/5 duty). It can
directly drive LCDs of up to 400, 320 and 240 segments when 1/5, 1/4 and 1/3 duty are selected respectively.
FEATURES
• Operating range
Supply voltage
: 3.0 to 5.5 V
Operating temperature range
:
40
to + 105C
• Segment output
: 80 pins
1/5 duty
: Up to 400 segments can be displayed.
1/4 duty
: Up to 320 segments can be displayed.
1/3 duty
: Up to 240 segments can be displayed.
• Serial transfer clock frequency
: 4 MHz
• Serical interface with CPU
:Through three input pins (DATA_IN, LOAD, and CLOCK)
• Built-in oscillator circuit for COMMON signals
• One-to-one correspondence between input data and output data
When input data is at “H” level
: Display goes on.
When input data is at “L” level
: Display goes off.
• The entire display can be turned off. (BLANK pin)
• Package options
100-pin plastic TQFP (TQFP100-P-1414-0.50-K) (Product name: ML9471TB)
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FEDL9471-01
LAPIS Semiconductor
ML9471
BLOCK DIAGRAM
SEG1
SEG80
BLANK
80-Dot Segment Driver
80-Ch Data Selector
80
80
80
80
80
80-Bit
Latch 5
80-Bit
Latch 4
80-Bit
Latch 3
80-Bit
Latch 2
80-Bit
Latch 1
LOAD
LATCH
SELECTOR
80
DATA_IN
CLOCK
88-Stage Shift Register
OSC_OUT
OSC_OUT
OSC_IN
OSC
TIMING
GENERATOR
V
LC1
V
LC2
V
LC3
DSEL1
DSEL2
COMMON
Driver
COM1
COM2
COM3
COM4
V
DD
COM5
GND
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FEDL9471-01
LAPIS Semiconductor
ML9471
PIN CONFIGURATION (TOP VIEW)
SEG29
SEG28
SEG 41
SEG 31
SEG 30
SEG 27
77
SEG47
SEG45
SEG43
SEG38
SEG35
SEG34
SEG50
SEG49
SEG48
SEG46
SEG42
SEG40
SEG39
SEG37
SEG36
SEG33
SEG44
SEG32
SEG 26
76
100
99
98
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
80
79
SEG51
SEG52
SEG53
SEG54
SEG55
SEG56
SEG57
SEG58
SEG59
SEG60
SEG61
SEG62
SEG63
SEG64
SEG65
SEG66
SEG67
SEG68
SEG69
SEG70
SEG71
SEG72
SEG73
SEG74
SEG75
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
78
75
74
73
72
71
70
69
68
67
66
65
64
63
62
61
60
59
58
57
56
55
54
53
52
51
SEG
25
SEG
24
SEG
23
22
SEG
SEG
21
SEG
20
SEG
19
SEG
18
SEG
17
SEG
16
SEG
15
SEG
14
SEG
13
SEG
12
SEG
11
SEG
10
SEG9
SEG8
SEG7
SEG6
SEG5
SEG4
SEG3
SEG2
SEG1
38
39
40
41
42
43
44
45
46
47
48
49
COM2
26
27
28
29
30
31
33
34
35
36
32
OSC_OUT
OSC_OUT
COM4
COM3
DATA_IN
OS C_IN
BLANK
SEG76
SEG77
SEG78
SEG79
SEG80
DSEL2
DSEL1
100-Pin Plastic TQFP
CLO CK
COM5
COM1
LOA D
GND
NC
V
LC1
V
LC3
V
LC2
V
DD
50
37
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FEDL9471-01
LAPIS Semiconductor
ML9471
PIN DESCRIPTION
Symbol
OSC_IN
OSC_OUT
OSC_OUT
DATA_IN
CLOCK
LOAD
BLANK
Type
I
O
O
I
I
I
Description
Pins for oscillation. The oscillator circuit is configured by externally connecting two
resistors and a capacitor. Make the wiring length as short as possible, because
the resistor connected to the OSC_IN pin has a higher value and the circuit is
susceptible to external noise.
Serial data input pin. The display goes on when input data is at a “H” level, and it
goes off when input data is at “L” level.
Shift clock input pin. Data from the DATA_IN pin is transferred in synchronization
with the rising edge of the shift clock.
Load signal input pin. Serially input data is transferred to the 80-bit latch at “H”
level of this load signal, then held at “L” level.
Input pin that turns off all segments. The entire display goes off when “L” level is
applied to this pin. The display returns to the previous state when “H” level is
applied.
Input pins to select 1/3, 1/4, or 1/5 duty. Following shows how each duty is
selected.
DSEL2
DSEL1
Duty selected
L
L
1/3
L
H
1/4
H
X
1/5
X: Don’t care
Display output pins for LCD. These pins are connected to the COMMON side of
the LCD panel.
Display output pins for LCD. Theses pins are connected to the SEGMENT side of
the LCD panel. For the correspondence between the output of these pins and
input data, see the “Data Structure” Section.
Bias pins for LCD driver. Through these pins, bias voltages for the LCD are
externally supplied. The bias potential must meet the following condition:
V
DD
> V
LC1
V
LC2
> V
LC3
=GND
Supply voltage pin and ground pin.
l
DSEL1
DSEL2
I
I
COM1 to
COM5
SEG1 to
SEG80
V
LC1
, V
LC2,
V
LC3
V
DD
, GND
O
O
—
—
Note: Built-in schmitt circuit is used for all input pins.
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FEDL9471-01
LAPIS Semiconductor
ML9471
ABSOLUTE MAXIMUM RATINGS
Parameter
Supply Voltage
Input Voltage
Storage Temperature
Power Dissipation
Output Current
Symbol
V
DD
V
I
T
STG
P
D
I
O
Condition
Ta = 25°C
Ta = 25°C
—
Ta < 105°C
—
Rating
–0.3 to 6.5
–0.3 to V
DD
+0.3
–55 to 150
700
–2.0 to 2.0
Unit
V
V
°C
mW
mA
RECOMMENDED OPERATING CONDITIONS
Parameter
Supply Voltage
CLOCK Frequency
Operating Temperature
Symbol
V
DD
f
CP
Ta
Condition
V
LC3
= GND
—
—
Range
3.0 to 5.5
1 to 4
–40 to 105
Unit
V
MHz
°C
Oscillator Circuit
Parameter
Oscillator Resistance
Oscillator Capacitance
Current Limiting Resistance
Symbol
R
0
C
0
R
1
Applicable pin
OSC_OUT
OSC_OUT
OSC_IN
Condition
—
—
—
Min.
20
0.00047
62
25
Max.
120
0.01
360
250
Unit
k
F
k
Hz
Common Signal Frequency
f
COM
COM1 to COM5
—
Note: See Section, “Reference Data”, for the resistor and capacitor values in the table.
RC Values in Oscillator Circuit
Parameter
Oscillator Resistance
Oscillator Capacitance
Current Limiting Resistance
Symbol
R
0
C
0
R
1
Applicable pin
OSC_OUT
OSC_OUT
OSC_IN
1/3 duty
68
0.001
220
1/4 duty
51
0.001
160
1/5 duty
43
0.001
130
Unit
k
F
k
Example of an oscillator circuit:
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