HT1647
4-Level Gray Scale 64 16 LCD Controller for I/O C
Rev. 1.00
1
June 1, 2001
Features
Operating voltage: 2.7V~5.2V
Built-in 32kHz RC oscillator
External 32.768kHz crystal oscillator or
32kHz frequency source input
Standby current: < 1 A at 3V, < 2 A at 5V
Internal resistor type: 1/5 bias or 1/4
bias, 1/16 duty
Two selectable LCD frame frequencies:
89Hz or 170Hz
Max.
64 16 patterns, 64 segments and 16
commons
Built-in bit-map display RAM: 2048 bits
(=64 16 2 bits)
Built-in internal resistor type bias generator
Six-wire interface (four data wires)
Eight kinds of time base/WDT selection
Time base or WDT overflow output
R/W address auto increment
Built-in buzzer driver (2kHz/4kHz)
Power down command reduces power
consumption
Software configuration feature
Data mode and Command mode
instructions
Three data accessing modes
ProvidesVLCDpintoadjustLCDoperating
voltage
Provides three kinds of bias current
programming
Control of TN-type, STN-type LCDs and
ECB-type LCDs
Four-level gray scale output for TN-type,
STN-type LCDs panel
Four-coloroutputforECB-typeLCDspanel
100-pin QFP and in chip form
General Description
HT1647 is a peripheral device specially de-
signed for I/O type
C used to expand the dis-
play capability. The max. display segment of
the device are 1024 patterns (64 segments and
16 commons). It also supports four data bits in-
terface, buzzer sound, Watchdog Timer or time
base timer functions. The HT1647 is a memory
mapping and multi-function LCD controller.
Since the HT1647 can control ECB-type (Elec-
trically Controlled Birefringence) LCDs in ad-
dition to current TN-type (Twisted Nematic) or
STN-type (Super Twisted Nematic) LCDs, it
can support 4-color display as well as 4-level
gray scale display. It displays 4-level gray scale
output when the HT1647 drives a TN-type,
STN-type LCDs. It displays four color output
when the HT1647 drives an ECB-type. HT1647
uses PWM (Pulse Width Modulation) tech-
nique. The software configuration feature of
the HT1647 make it suitable for multiple LCD
applications including LCD modules and dis-
play subsystems. Only six lines (CS, WR,
DB0~DB3) are required for the interface be-
tween the host controller and the HT1647.
Applications
Leisure products
Games
Personal digital assistant
Cellular phone
Global positioning system
Consumer electronics