UPD78F1502AGK-GAK-AX Datasheet, PDF (719/1031 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcontrollers

78K0R/Lx3
CHAPTER 16 LCD CONTROLLER/DRIVER
16.8 Supplying LCD Drive Voltages VLC0, VLC1, VLC2, and VLC3
With the 78K0R/Lx3 microcontrollers, a LCD drive power supply can be generated using either of three types of
methods: external resistance division method, internal voltage boosting method, or capacitor split method.
16.8.1 External resistance division method
The 78K0R/Lx3 microcontrollers can also use external voltage divider resistors for generating LCD drive power
supplies, without using internal resistors. Figure 16-31 shows examples of LCD drive voltage connection, corresponding to
each bias method.
Figure 16-31. Examples of LCD Drive Power Connections (External Resistance Division Method) (1/2)
(a) Static display mode
(b) 1/2 bias method
VLC0
VLC1
VLC2
VLC3
VSS
VDD
VLC0
VLC1^Note1
VLC2^Note1
VLC3/P02^Note2
VSS
VLC0
VLC1
VLC2
VLC3
VSS
VDD
VLC0
R
VLC1
VLC2
R
VLC3/
P02^Note
VSS
VLC0 = VDD
VLC0 = VDD
Notes 1. Connect VLC1 and VLC2 directly to GND or VLC0. Note VLC3 can be used as port (P02).
2. VLC3 can be used as port (P02).
Caution To stabilize the potential of the VLC0 to VLC3 pins, it is recommended to connect a capacitor of about
0.1 μF between each of the pins from VLC0 to VLC3 and the GND pin as needed.
R01UH0004EJ0501 Rev.5.01
703
Jun 20, 2011