LC75844M Datasheet, PDF (5/14 Pages) Sanyo Semicon Device – 1/4 Duty General-Purpose LCD Driver

LC75844M
Pin Functions
Pin
S1/P1 to
S4/P4
S5 to S22
COM1
COM2
COM3
COM4
OSC
CE
CL
DI
INH
V_LCD1
V_LCD2
V_DD
V_LCD
V_SS
Pin No.
1 to 4
5 to 22
23
24
25
26
Function
Segment outputs for displaying the display data transferred by serial data input. The pins
S1/P1 to S4/P4 can be used as general-purpose output ports when so set up by the
control data.
Common driver outputs.
The frame frequency f_O is given by: f_O = (f_OSC/512) Hz.
32
Oscillator connection
An oscillator circuit is formed by connecting an external resistor and capacitor to this pin.
34
35
36
Serial data transfer inputs. These pins are
connected to the control microprocessor.
CE: Chip enable
CL: Synchronization clock
DI: Transfer data
Display off control input
•INH = low (V_SS): Off
S1/P1 to S4/P4 = Low
(These pins are forcibly set to the segment output port function and
33
fixed at the V_SS level.)
S5 to S22 = Low (V_SS),
COM1 to COM4 = Low (V_SS)
•INH = high (V_DD): On
Note that serial data transfers can be performed when the
display is forced off by this pin.
Used to apply the LCD drive 2/3 bias voltage externally. This pin must be connected to
29
V_LCD2 when 1/2 bias drive is used.
Used to apply the LCD drive 1/3 bias voltage externally. This pin must be connected to
30
V_LCD1 when 1/2 bias drive is used.
27
Logic block power supply. Provide a voltage in the range 2.7 to 6.0 V.
28
LCD driver block power supply. Provide a voltage in the range 2.7 to 6.0 V.
31
Ground pin. Connect to ground.
Active
I/O
Handling
when unused
—
O
Open
—
O
Open
— I/O
H
I
—
V_DD
GND
L
I
GND
—
I
—
I
—
—
—
—
—
—
Open
Open
—
—
—
Serial Data Transfer Format
1. When CL is stopped at the low level
CE
CL
DI 0 0 1 0 0 0 1 0 D1 D2 D3
B0 B1 B2 B3 A0 A1 A2 A3
CCB address
8 bits
D37 D38 D39 D40 D41 D42 D43 D44 0 0 0 0 0 P0 P1 P2 DR SC BU 0
Display data
44 bits
Control data
DD
11 bits
1 bit
0 0 1 0 0 0 1 0 D45 D46 D47
B0 B1 B2 B3 A0 A1 A2 A3
CCB address
8 bits
Note: DD ... Direction data
D81 D82 D83 D84 D85 D86 D87 D88 0 0 0 0 0 0 0 0 0 0 0 1
Display data
44 bits
Fixed data
11 bits
DD
1 bit
A12600
No. 6235-5/14