EM65571AGH EMC [ELAN Microelectronics Corp], EM65571AGH Datasheet - Page 68

• Manufacturer Part Number: EM65571AGH
• Description: 130COM / 128SEG 65K Color STN LCD Driver
• Manufacturer: EMC [ELAN Microelectronics Corp]

EM65571
130COM/128SEG 65K Color STN LCD Driver
62 •
7.32
High current that may flow if a voltage is supplied to the LCD driver power supply while the
system power supply is floating may permanently damage this LSI. The details are as
follows.
Note: Connect a serial resistor (50 to 100Ω) or fuse to the LCD driver power V0 or VOUT
If the VDD and VEE voltages are not of the same potential, turn on the power logic system
(VDD) first.
If VDD and VEE are not of the same potential, turn off the VEE first. After VEE, VOUT, V0,
V1, V2, V3 and V4 voltages are below LCD ON voltage (threshold voltage for Liquid crystal
turn on), power off the logic system (VDD).
Though especially there is no constraint on the rising time of the power supply, the “tr”
(rising time) of the following is recommended in the practical use.
Precautionary Measures during Power ON and Power OFF
7.32.1 When Using an External Power Supply
7.32.2
7.32.3
(when using only an internal voltage conversion circuit) of the system as a current
limiter. Moreover, set up suitable resistor values corresponding to the LCD display
grade.
VDD, VEE
o Logic system (VDD) power ON, make reset operation.
o Supply external LCD driver voltage to corresponding pins (V0, V1, V2, V3 and V4)
o Set HALT register to “1” or initiate a reset operation.
o Cut off external LCD driver voltage.
o Logic system (VDD) power OFF.
o Logic system (VDD) power ON
o Booster circuit system (VEE) power ON
o Initiate a reset operation, enable booster and voltage conversion circuit.
o Set the HALT register to “1” or reset the system.
o Booster circuit system (VEE) power OFF.
o Logic system (VDD) power OFF.
Procedure for Power ON
Procedure for Power OFF
Procedure for Power ON
Procedure for Power OFF
When Using a Built-in Power Supply
Power Supply Rising Time
tr
(This specification is subject to change without further notice)
Product Specification (V1.0) 08.04.2005