HD66727

  Control and drive of a dot-matrix LCD with built-in key scan functions
  Four 12-character lines, 40 segments, and 12 annunciators
  Control of up to a 4 `  8-key matrix, 3 LED ports and 3 general ports
  Low-power operation support:
     2.4 to 5.5V (low voltage)
     Double or triple booster for liquid crystal drive voltage
     Contrast adjuster and voltage followers for decreasing the direct current flow in the LCD drivebleeder-resistors
     Standby mode and sleep mode
     Displays up to 12 static annunciators
  I<sup>2</sup>C bus or clock-synchronized serial interface
 60  8-bit display data RAM (60 characters max)
 11,520-bit character generator ROM
    240 characters (6 `  8 dots)
 32 `  6-bit character generator RAM
    4 characters (6 `  8 dots)
 8   6-bit segment RAM
   40 segment-icons and marks max
  60-segment   34-common liquid crystal display driver
  Programmable display sizes and duty ratios (see Table 1)
  Vertical smooth scroll
  Vertical double-height display of all character fonts
  Horizontal double display with dedicated character fonts (6-dot font width used)
  Wide range of instruction functions:
     Clear display, display on/off control, icon and mark control, character blink, white-black inverting
     blinking cursor, icon and mark blink, return home, cursor on/off, white-black inverting raster-row
  Internal oscillation with an external resistor
  Hardware reset
  Wide range of LCD drive voltages
     3.0V to 13.0V
  Slim chip with bumps for chip-on-glass (COG) mounting, slim chip without bumps for chip-on-board(COB) mounting, and tape carrier package (TCP) (under development)

The HD66727, dot-matrix liquid crystal display controller and driver LSI incorporating a key scanfunction, displays alphanumerics, katakana, hiragana, and symbols. It can be configured to drive a dot-matrix liquid crystal display and control key scan functions under the control of an I²C bus or a clock-synchronized serial microprocessor. A single HD66727 is capable of displaying up to four 12-characterlines, 40 segments, and 12 annunciators, and controlling up to a 4-by-8 key matrix, and driving three LED.The HD66727 incorporates all the functions required for driving a dot-matrix liquid crystal display such asdisplay RAM, character generator, and liquid crystal drivers, and it alsoincorporates a booster for the LCDpower supply and key scan functions.

The HD66727 provides various functions to reduce the power consumption of an LCD system such as low-voltage operation of 2.4V or less, a booster for generating a maximum of triple LCD drive voltage from thesupplied voltage, and voltage-followers for decreasing the direct current flow in the LCD drive bleeder-resistors. Combining these hardware functions with software functions such as standby and sleep modesallows a fine power control. The HD66727, with the above functions, is suitable for any portable battery-driven product requiring long-term driving capabilities and small size.