em65567 ELAN Microelectronics Corp, em65567 Datasheet - Page 42

• Manufacturer Part Number: em65567
• Description: Com/ Color Driver
• Manufacturer: ELAN Microelectronics Corp

EM65567
66 COM/ 96 SEG 256 Color STN LCD Driver
7.29 Precaution when Power ON and Power OFF
This LSI may be permanently damaged by high current that may flow if a voltage is supplied to the LCD driver power supply
while the system power supply is floating. The detail is as follows.
( i )When using as external power supply
• Procedure for Power ON
(1) Logic system (VDD) power ON, make reset operation.
(2) Supply external LCD drive voltage to corresponding pins (V0, V1, V2, V3 and V4)
• Procedure for Power OFF
(1) Set HALT register to “1” or make reset operation.
(2) Cut off external LCD drive voltage.
(3) Logic system(VDD) power OFF.
Note: connect the serial resistor (50 to 100Ω) or fuse to the LCD drive power V0 or VOUT(when only use internal voltage
conversion circuit) of the system as a current limiter. Moreover, set up the suitable value of the resistor in consideration of
LCD display grade.
( ii )When using the built-in power supply
• Procedure for Power ON
(1) Logic system (VDD) power ON
(2) Booster circuit system (VEE) power ON
(3) Make reset operation, booster and voltage conversion circuit enable.
If VDD and VEE voltages aren’t same potential, power on logic system (VDD) first.
• Procedure for Power OFF
(1) Set HALT register to “1” or make reset operation.
(2) Booster circuit system (VEE) power ON
(3) Logic system (VDD) power OFF.
If VDD and VEE are not same potential, cut off 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 logic system (VDD).
( iii )Power supply rising time
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.
* This specification is subject to be changed without notice.
42
2003/1/9 (V0.1)