E202075_HD404889 Datasheet, PDF (147/202 Pages) Renesas Technology Corp – Low-Voltage AS Microcomputers with On-Chip LCD Circuit

HD404889/HD404899/HD404878/HD404868 Series
LCD drive voltage (V_LCD):
Example of LCD drive power supply wiring are shown in figures 91-1 and 91-2. The LCD drive voltage
(V_LCD) should be within the following range.
2.2≤V_LCD≤V_CC (V)
If the LCD drive voltage is applied from off-chip, connect the V0 pin to V_CC and turn the LCD power
switch (LCD control register) off. (HD404889/HD404899/HD404878 Series)
When the power supply voltage is used as the LCD drive voltage, the V0 and V1 pins should be shorted.
(HD404889/HD404899/HD404878 Series)
VCC
VCC
VCC
VLCD
VCC
VLCD
VCC
V0
V1
V2
V3
GND
COM1
SEG1
to
SEG32
1
32
4-digit LCD
Static drive (power supply voltage used for VLCD)
VCC
V0
V1
V2
V3
GND
COM1
COM2
SEG1
to
SEG32
2
32
8-digit LCD
1/2 duty, 1/2 bias drive (power supply voltage used for VLCD)
VCC
V0
V1
V2
V3
GND
COM1
to
COM3
SEG1
to
SEG32
3
32
10-digit signed LCD
1/3 duty, 1/3 bias drive (external power supply used for VLCD)
VCC
V0
V1
V2
V3
GND
COM1
to
COM4
SEG1
to
SEG32
4
32
16-digit LCD
1/4 duty, 1/3 bias drive (external power supply used for VLCD)
Figure 91-1 Examples of LCD Wiring (HD404889/HD404899/HD404878 Series)
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