ST8024T
8.
PRECAUTIONS
Precautions when connecting or disconnecting the power supply
This IC has a high-voltage LCD driver, so it may be permanently damaged by a high current which
may flow if voltage is supplied to the LCD drive power supply while the logic system power supply
is floating. The details are as follows,
ꢂ When connecting the power supply, connect the LCD drive power after connecting the logic
system power. Furthermore, when disconnecting the power, disconnect the logic system power
after disconnecting the LCD drive power
ꢂ It is advisable to connect the serial resistor (50 to 100 Ω) or fuse to the LCD drive power V0 of
the system as a current limiter. Set up a suitable value of the resistor in consideration of the
display grade.
And when connecting the logic power supply, the logic condition of this IC inside is insecure.
Therefore connect the LCD drive power supply after resetting logic condition of this IC inside on
/DISPOFF function. After that, cancel the /DISPOFF function after the LCD drive power supply
has become stable. Furthermore, when disconnecting the power, set the LCD drive output pins to
level LGND on /DISPOFF function. Then disconnect the logic system power after disconnecting
the LCD drive power.
When connecting the power supply, follow the recommended sequence shown here
VDD
VDD
LGND
VDD
/DISPOFF
LGND
V0
V0
GND
.
Preliminary Ver 0.12
Page 15/26
2008/01/24
SITRONIX [ SITRONIX TECHNOLOGY CO., LTD. ]
