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May 18, 2000
Hitachi Releases HD66761 STN Color LCD Controller Driver
- 128 x 80-pixel, 256-color display provided by a single chip -
Hitachi, Ltd. (TSE: 6501) today announced the HD66761 LCD controller driver, providing single
-chip drive for STN color graphics LCD panels with the industry's largest display screen size 
of 128 x 80pixels, and capable of displaying 256 colors, for use with liquid crystal displays 
on mobile communication terminals such as digital mobile phones with a built-in simple browser.  
Sampleshipments will begin on May 18, 2000 in Japan.

With the HD66761, 256-color display can be achieved on landscape or portrait format color LCD 
panels of up to 128 x 80 pixels, using a single chip, or up to 128 x 160 pixels, using two 
chips,enabling portable mobile communication terminals to handle information distribution 
services such as e-mail and WWW contents including Internet color images.

Digital mobile phones are rapidly becoming widely used not only as telephone voice terminals,
but also as data communication terminals handling information distribution services such as 
e-mail and WWW contents.  With the growing volume of display information involved in image 
display, in addition to text-based displays such as phone numbers and kanji messages, 
the trend in small LCD panels on portable phones is to color graphics display capability 
and larger size.

Hitachi has previously released the four-grayscale monochrome display HD66750/751 
(128 x 128 dots) and HD66752 (168 x 132 dots) as STN liquid crystal display drivers for mobile 
communicationterminals.  To meet the strong market demand for color display capability, Hitachi 
has now developed the HD66761 LCD driver offering single-chip implementation of a 256-color 
display with a 128 x 80-pixel screen size.

When using a 12 x 12-pixel kanji font, up to 60 characters (6 lines of 10 characters) can be 
displayed with a single HD66761 chip, while using two chips in a coupled configuration by means 
of the master-slave function makes possible a display of up to 120 characters 
(12 lines of 10 characters), sufficient for longer e-mail messages.  In addition, on-chip bit 
operation functions*1 provide smooth processing of largeamounts of data, such as color image 
data, making it possible to greatly reduce the graphics processingload on the microcomputer 

Larger screen sizes and color display capacity not only require a higher LCD drive voltage, but 
are also associated with lower display quality and increased current dissipation.

The HD66761 has an on-chip maximum 7x step-up circuit.  With color display on a 128 x 80-pixel 
screen requiring an LCD drive voltage of approximately 14 V, use of the step-up circuit enables 
an LCD drive voltage of approximately 15.4 V at 2.2 V power supply voltage.

To counter any decrease in display quality, the LCD drive voltage generation op-amp and step-up 
circuit drive current can be controlled by software, allowing current dissipation to be held 
down to the minimum necessary level while maintaining display quality.  Also, since image 
display involves higher LCD panel power consumption, and greater voltage fluctuations, than 
text display, contrast variations are also greater.  However, an on-chip voltage regulation 
circuit enables the voltage to be stabilized and contrastvariations to be suppressed.  
The HD66761 employs the C-pattern LCD drive method used in large LCD display systems.  With 
this method, the alternation frequencies of the illuminated and non-illuminated parts of 
the LCD display are made uniform, reducing the crosstalk noise due to contrast variations 
associated with alternation frequency deviation.

To reduce current dissipation, a partial display function is provided that enables only a part 
of the screen display area to be driven.  The upper and lower display areas can be driven 
independently, enabling display to be performed with a lower LCD drive duty*2.  For example, 
when displaying seven lines of icons at the top of the screen and 17 message lines in 
the center, both displays can be driven at a duty of 1/24.

Supported mounting methods are COF*3 mounting, in which the device is mounted face-down 
on a flexible film substrate, and TCP*4 mounting, in which the device is connected directly 
to the LCD glass.

Hitachi plans to extend the product lineup in the future with the development of models capable
of handling even larger screen sizes.

Notes:	1.Bit operation functions: Data processing functions that perform data rewriting and 
          computational operations in display RAM for individual display dots.

	2.LCD drive duty: Ratio of the drive time for a single line on an LCD screen to the 
          time for one frame of which the line is a part.

	3.COF (Chip On Film): A mounting method in which a die with gold bump is directly 
          mounted  face-down on a flexible film substrate.

	4.TCP (Tape Carrier Package): A package in which the chip is mounted on a thin-film 
          tape.	Ultra-thin type mounting is possible.

< Typical Applications >

· Mobile phones handling e-mail and WWW contents services

· Mobile phones supporting high-speed data transfer (W-CDMA, GSM)

· Small PDAs, handheld GPS terminals, handheld POS terminals

· Portable digital audio players
< Prices in Japan > (For Reference)
Product CodeShipment FormSample Unit Price (Yen)
HCD66761BPDie with gold bump1,600
HD66761TB0Bending TCP2,200

< Specifications >
ItemHD66761 Specifications
Display size128 x 80 pixels, 256 colors
Number of outputs384 segment outputs
80 common outputs
On-chip RAM for display81.92 kbits
Display functions· Hardware color window cursor display
(arbitrary rectangular area: 8 colors specifiable)
· Split-screen partial display function (screen division at arbitrary line)
· 4-pixel-unit horizontal scrolling
Bit operation functions· Write data mask function (bit units)
· Bit operation function (pixel units)
· Specified color comparison drawing decision function
LCD drive duty1/16 to 1/80 (programmable in 8-line units)
LCD drive bias1/5 to 1/10 (programmable)
LCD drive step-up circuit output4x, 5x, 6x, 7x (programmable)
Interface68/80-type 8/16-bit bus interface
Write cycle300 ns
Logic power supply voltage2.2 V to 3.6 V
LCD drive voltage5 V to 15.5 V
Shipment forms· Die with gold bump (for COF mounting)
· Bending TCP

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(C) Hitachi, Ltd. 2000. All rights reserved.