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News Release

February 18, 1999

Hitachi Releases HD66729 Graphic LCD Controller/Driver for Mobile Communication Products, Offering 105 x 68-Dot Large-Screen Graphic Display on 1.8 V Low-Voltage Single-Power-Supply

- Powerful on-chip power management functions, including programmable voltage step-up ratio, for lower power consumption in LCD systems -

Hitachi, Ltd. (NYSE:HIT) today announced, as an addition to its grapic LCD controller/driver series lineup, 
the HD66729 LCD controller/driver for LCD display systems in mobile communication products such as 
digital cellular phones, PHS phones, and message pagers, capable of 105 x 68-dot graphic display*1 at 1.8 V 
single-power-supply voltage operation.  Sample shipments will begin on February 19, 1999 in Japan.

The HD66729 has an on-chip 5X step-up circuit that enables a large-screen LCD panel to be driven by a 
single-power-supply voltage of 1.8 V, plus enhanced power management features including a programmable 
voltage step-up ratio.  These features make it possible to reduce the voltage and power consumption of the 
end-product.  The product lineup includes COG*2, COF*3, and TCP*4 mounting types to meet a variety of 
users' needs.

With the rapid growth of the market for mobile communication products such as cellular and PHS phones, 
there is a constant trend toward slimmer and lighter products, together with lower costs, and the overall 
system voltage is decreasing year by year.  Meanwhile, to meet the need for multifunctionality and higher 
added value, it has also become necessary for the small LCD panels used in these products to provide a 
large-screen-size graphic display capable of implementing additional functions such as information services 
that include kanji messages and e-mail, and WWW contents, as well as the conventional phone number 
display and directory functions.

Hitachi is currently mass-producing the HD66726, with a 96 x 42-dot display capability, as a graphic LCD 
controller/driver offering dot matrix display and fixed character display (including alphanumeric and kana 
characters) in a single-chip.  The new HD66729 now enables LCD panels with a larger screen size to be 
implemented at a lower voltage.

The current HD66726 can step-up the system power supply voltage by up to 4 times to generate the LCD 
drive voltage.  However, this means that the maximum LCD drive voltage in a system with a 1.8 V power 
supply voltage is only 7.2 V, not enough to drive a large-screen LCD with a vertical size of around 65 to 68 
dots.

In view of this, the new HD66729 includes a 5X step-up circuit capable of generating an LCD drive voltage 
of up to 9 V in a system with a 1.8 V power supply voltage, making possible LCD displays with a vertical 
size of up to 68 dots.  This enables the overall system voltage to be reduced and drastically cuts the total 
current dissipation of the system, allowing smaller, lighter batteries to be used.

In general, as the LCD vertical screen size (LCD drive duty) increases, so does the LCD drive voltage, with 
an accompanying rise in current dissipation, but the HD66729 incorporates features to minimize these 
increases.

An LCD drive duty setting from 1/8 to 1/68 can be programmed by software as desired, and the step-up 
output multiplication factor and LCD drive bias ratio can also be controlled by software.  For example, with 
the 105 x 68-dot (1/68 duty) screen size in normal operation, use of the 5X step-up circuit enables LCD 
drive to be carried out with a 9 V LCD drive voltage, and by performing software switching during system 
standby periods to enable the 105 x 8-dot (1/8 duty) pictogram and icon display area to be driven at 3.6 V 
using the 2X step-up circuit, it is possible to cut the LCD panel charge/discharge current by approximately 
75%.  In addition, since the LCD drive bias ratio can be adjusted by software, the bias ratio can be kept low 
through the use of liquid crystal materials with excellent on/off transient characteristics in the system 
configuration stage, thus enabling the LCD drive voltage itself to be reduced.

When only part of the screen is used for display, if the LCD drive duty is set low the display will be biased 
toward the top of the screen when the LCD drive duty is set low.  While the pictogram display on cellular 
phones, etc., is at the top of the screen, in other systems the display is often in the center of the screen, and 
therefore a centering display function is supported which shifts the LCD drive area to the center of the 
display screen.  This allows center-screen message, time, or calendar display to be selected while the system 
is on standby.

A partial smooth scroll display function is also supported that allows the selection of fixed display of 
pictograms only at the top of the screen in cellular phones, etc., while performing vertical smooth scrolling 
of the rest of the display area.

With most cellular phones, the width of the set itself limits the horizontal display size to around 100 dots.  
With the HD66729, the number of LCD driver outputs has been cut by stretching the horizontal display size 
to a maximum of 105 dots, resulting in a chip size 20% smaller than previous products (Hitachi 
comparison).  This means lower costs and also, in the case of COG mounting, results in a slim chip shape, 
with a width of only 2.52 mm, that enables the mounting glass area to be kept to a minimum.

For interfacing to a microcomputer, the HD66729 includes a high-speed synchronous serial interface and a 
68/80-type 8-bit or 4-bit bus interface.  Access to on-chip registers and RAM can be performed by 
continuous high-speed writing, independently of the internal operating clock frequency, enabling fast data 
transfer to be achieved even over a serial interface.

The mounting methods supported are COG mounting, in which the device is directly mounted face-down on 
the LCD glass, COF mounting, in which the device is mounted face-down on a flexible film substrate, and 
TCP mounting, in which the device is connected to the LCD glass via a heat seal.

Hitachi plans to extend the lineup in the future by developing models supporting even larger display sizes 
and models supporting gray-scale display, based on the HD66729.


Notes:	1.	Graphic display: 
		On-chip bit-mapped display RAM is provided, and the microcomputer can display arbitrary 
		patterns such as kanji and game patterns.
	
	2.	COG (Chip On Glass): 
		A mounting method in which a chip with a gold bump is directly mounted face-down on the 
		LCD glass.
	
	3.	COF (Chip On Film): 
		A mounting method in which a chip with a 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 >
- Digital cellular systems (PDC, GSM, CDMA, etc.), PHS
- Digital cordless phones, fax machines
- Bidirectional pagers, kanji/Chinese-language pagers, electronic wallets, etc.

< Prices in Japan > (For Reference Only)
Product Code		Display Size		Shipment Form		Mounting Form	Sample Price (Yen)     
HCD66729BP		105 x 68 dots		Chip with gold bump	COG, COF	     450          
HD66729TB0		105 x 68 dots		Bent-lead TCP		TCP		     650          


WRITTEN BY Secretary's Office
All Rights Reserved, Copyright (C) 1999, Hitachi, Ltd.