HD66420 Datasheet, PDF (1/52 Pages) Hitachi Semiconductor – (RAM-Provided 160 Channel 4-Level Grey Scale Driver for Dot Matrix Graphics LCD)

HD66420
(RAM-Provided 160 Channel 4-Level Grey Scale Driver for Dot
Matrix Graphics LCD)
Description
The HD66420 drives and controls a dot matrix graphic LCD(Liquid Crystal Display) using a bit-mapped
method. It provides a highly flexible display through its on-chip display RAM, in which each two bits of
data can be used to turn on or off one dot on LCD panel with four-level grey scale.
A single HD66420 can display a maximum of 160x80 dots using its powerful display control functions. It
can display only eight lines out of eighty lines. This function realize low power consumption because high
voltage for driving LCD is not needed.
An MPU can access HD66420 at any time, because the MPU operations are asynchronous with the
HD66420’s system clock and display operation.
Its low-voltage operation at 2.2 to 5.5V and standby function provides low power dissipation, making the
HD66420 suitable for small portable device applications.
Features
• Built-in bit-mapped display RAM: 25.6kbits (160 × 80 × 2 bits)
• Grey scale display: PWM four-level grey scale can be selected from 32 levels
• Grey scale memory management: Packed pixel
• Partial display: Eight-lines data can be displayed in any place
• An 80-system MPU interface
• Power supply voltage for operation : 2.2V to 5.5V
• Power supply voltage for LCD : 13 V max.
• Selectable multiplex duty ratio: 1/8, 1/32, 1/64, 1/80
• Built-in oscillator: external resister
• Low power consumption:
 55µA typ. 80µA max. during display
 0.1µA typ. 5µA max. during standby
• Circuits for generating LCD driving voltage : Contrast control, Operational amplifier, and Resistive
dividers
• Internal resistive divider: programmable bias rate
• 32-level programmable contrast control
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