HD66760 Datasheet, PDF (13/105 Pages) Hitachi Semiconductor – 104 X 80-dot Graphics LCD Controller/Driver for 256 Colors

HD66760
SGS bit. The shift direction for the common driver can also be changed by the CMS bit by selecting an
appropriate direction for the device mounting configuration.
When multiplexing drive is not used, or during the standby or sleep mode, all the above common and segment
signal drivers output the GND level, halting the display.
Step-up Circuit (DC-DC Converter)
The step-up generates three-, four-, five-, or six-times voltage input to the Vci pin. With this, both the internal
logic units and LCD drivers can be controlled with a single power supply. Step-up output level from three-
times to six-times step-up can be selected by software. For details, see the Power Supply for Liquid Crystal
Display Drive section.
V-Pin Voltage Follower
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. This internal bleeder-resistor can be software-specified from 1/4 bias to
1/10 bias, according to the liquid crystal display drive duty value. For details, see the Power Supply for Liquid
Crystal Display Drive section.
Contrast Adjuster
The contrast adjuster can be used to adjust LCD contrast in 128 steps by varying the LCD drive voltage by
software. This can be used to select an appropriate LCD brightness or to compensate for temperature.
Power-supply Regulator
The power-supply regulator generates the LCD drive voltage from the reference voltage, which does not
depend on the LCD load current. The fluctuating LCD drive voltage can be controlled for the fluctuating
LCD load current. For details, see the Liquid Crystal Display Voltage Generator section.
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