MSM6222 OKI [OKI electronic componets], MSM6222 Datasheet - Page 33

• Manufacturer Part Number: MSM6222
• Description: DOT MATRIX LCD CONTROLLER WITH 16-DOT COMMON DRIVER AND 40-DOT SEGMENT DRIVER
• Manufacturer: OKI [OKI electronic componets]

¡ Semiconductor
Display examples when setting the 5 x 7 dots character font 1-line mode, 5 x 10 dots character font
1-line mode, and 5 x 7 dots character font 2-line mode through instructions are shown in Figures
4, 5, and 6, respectively.
When the 5 x 7 dots character font is set in the 1-line display mode, the COM signals COM
COM
Likewise, when the 5 x 10 dots character font (1-line is set), the COM signals COM
are output for display-off.
The display example shows a combination of 16 characters (32 characters for the 2-line display
mode) and the LCD. When the number of MSM5259s are increased according to the increase in
the number of characters, it is possible to display a maximum of 80 characters.
Besides, it is necessary to generate bias voltage required for LCD operation by splitting resistors
outside the IC to input it to MSM6222B-xx and MSM5259.
Examples of these bias voltages are shown in Figures 7, 8, 9, and 10. Basically, this can be done
by dividing the voltage by the resistors as shown in Figures 7 and 8. If the value of resistor R is
made larger to reduce system power consumption, the LCD operating margin decreases and the
LCD driving waveform is distorted. To prevent this, a by-pass capacitor is serially connected to
the resistor to lower voltage division impedance caused by the splitting of resistors as shown in
Figures 9 and 10.
As the values of R, VR, and C vary according to the LCD size used and V
these values have to be determined through actual experimentation in combination with the
LCD.
(Example set values: R = 3.3 to 10kW, V
Figure 17 shows an application circuit for the MSM6222B-xx and MSM5259 including a bias
circuit.
The bias voltage has to maintain the following potential relation:
Interface with LCD and MSM5259
• In the case of 1-line 16 characters display (5 x 7 dots/font)
16
are output for extinguishing.
V
DD
COM
COM
> V
1
8
1
> V
MSM6222B-xx
2
SEG
V
1
3
> V
4
> V
5
R
DF
= 10 to 30kW, and C = 0.0022 mF to 0.047 mF)
Figure 4
L
SEG
40
DO
CP
DI
CP
1
O
1
LOAD
MSM5259
DF
LCD
DO
(LCD drive voltage),
20
DI
21
MSM6222B-xx
O
40
12
to COM
LCD
33/45
9
to
16