HD66717 Datasheet, PDF (16/90 Pages) Hitachi Semiconductor – (Low-Power Dot-Matrix Liquid Crystal Display Controller/Driver)

HD66717
Booster
The booster doubles or triples a voltage input to the Vci pin. With this function, both the internal logic
units and LCD drivers can be controlled with a single power supply.
Oscillator
The HD66717 can provide R-C oscillation simply by adding an external oscillation resistor between the
OSC1 and OSC2 pins. The appropriate oscillation frequency for operating voltage, display size, and
frame frequency can be obtained by adjusting the external-resistor value. Clock pulses can also be
supplied externally. Since R-C oscillation is halted during standby mode, current consumption can be
reduced.
V-Pin Voltage-Followers
A voltage-follower for each voltage level (V1 to V5) reduces current consumption by the LCD drive
power supply circuit. No external resistors are required because of the internal bleeder-resistor, which
generates different levels of LCD drive voltage. The voltage-followers can be turned off while
multiplexing drive is not being used.
Contrast-Adjuster
The contrast-adjuster can adjust LCD contrast by varying LCD drive voltage by software. This function is
suitable for selecting appropriate brightness of the LCD or for temperature compensation.
1 2 3 4 5 6 7 8 9 10 11 12
00 01 02 03 04 05 06 07 08 09 0A 0B
Display position
DDRAM address
Cursor position
Note: The cursor/blink or white-black inversion control is
also active when the address counter indicates the
CGRAM or SEGRAM. However, it has no effect on the
display.
Figure 2 Cursor Position and DDRAM Address
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