EM65101
128COM/160SEG 16 Gray Scale Level LCD Driver
The ratio of the resistance at the CR oscillator is programmable. When you change this
ratio, the frame frequency display is also changed.
7.8 Power Supply Circuit
This power circuit supplies the voltages necessary to drive an LCD. The circuit
consists of a booster and a voltage converter.
Boosted voltage from the booster is fed to the voltage converter that converts this input
voltage into V0, V1, V2, V3, and V4 that are used to drive the LCD. This internal power
supply should not be used to drive a large LCD panel containing many pixels.
Otherwise, the display quality will be degraded considerably. Instead, use an external
power supply. When using external power supply, turn off the internal power supply
(AMPON, DCON=”00”), disconnect pins CAP1-, CAP1+, CAP2+, CAP2-, CAP3+,
CAP3-, CAP4+, CAP5+,V2X, VOUT, and VEE. Then, feed the external LCD drive
voltages to Pins V0, V1, V2, V3, and V4. The power circuit can be controlled by power
circuit related registers.
DCON
AMPON
Booster Circuit
Disable
Voltage Conversion Circuit
0
0
1
0
1
1
Disable1
Enable2
Enable
Disable
Enable
1 Because the booster and the voltage converter are not operating, disconnect Pins
CAP1+, CAP1-, CAP2+, CAP2-, CAP3+, CAP3-, CAP4+, CAP5+,V2X, VOUT and
VEE.
Apply external LCD drive voltages to the corresponding pins.
2 Because the booster is not operating, disconnect Pins CAP1+, CAP1-, CAP2+,
CPA2-, CAP3+, CAP3-, CAP4+, CAP5+, and VEE.
Derive the voltage source to be supplied to the voltage converter from VOUT and the
V2X pins.
7.9 Booster Circuit
Placing capacitor C1 across CAP1+ and CAP1-, across CAP2+ and CAP2-, across
CAP3+ and CAP3-, across CAP4+ and CAP2-, across CAP5+ and CAP3-, and across
VOUT/V2X and VSS, will boost the voltage coming from VEE and VSS n-times and
output the boost up voltage to the VOUT pin. Voltages that are boost-up twice, three
times, four times, and five times are output to the VOUT pin by the boost step register
set. You can set the boost step registers.
(1) In cases where the twice boost-up voltage is used, place C1 across CAP1+ and
CAP1- , across V2X and VSS; and open CAP2+, CAP2-, CAP3+, CAP3-, CAP4+,
CAP2-, CAP5+, and CAP3-.
(2) In cases where the voltage that is boosted three times is used, place C1 only
across CAP1+ and CAP1-, across CAP2+ and CAP2- , across V2X and VSS; and
open CAP3+, CAP3-, CAP4+, CAP2-, CAP5+, and CAP3-
Product Specification (V0.4) 08.15.2005
• 23
(This specification is subject to change without further notice)
ELAN [ ELAN MICROELECTRONICS CORP ]
