Specifications

EPSON 5–11
SED1225 Series
SED1225
Series
Voltage regulator
• Voltage regulator using the electronic control function
Use the electronic control function and set the voltages
appropriate to the LCD panel driving.
When a 5-bit data is set in the electronic control
register, one of 32-state voltages can be set for LCD
driving. Before using the electronic control function,
turn ON the power circuit by issuing the power
control command.
The following explains how to calculate the voltages
using the electronic control function.
V
5 = 4 × VEV
Conditions:
VEV = VREG2 – X
where,
X = nα (n=0, 1, ..., 31)
α = VREG2/95
External unit connection examples
An external voltage regulation capacitor must be
connected to the LCD power pin. The LCD drive
voltages are fixed to 1/4 biasing.
1/4 bias example
Power Save mode
The SED1225 supports the Standby and Sleep modes to
save the power consumption during system idling.
• Standby mode
The Standby mode is selected or released by the
Power Save command. During Standby mode, only
the static icon is displayed.
1. LCD display outputs
COM1 to COM16, COMS1, COMS2:
V
DD level
SEG1 to SEG60, SEGS1, 2, 4, 5:
VDD level
SEGSA, B, C, D, E, F, G, H, I, J, COMSA:
Can light by static drive
Use the Static Icon RAM to display the static icon
with SEGSA, B, C, D, E, F, G, H, I, J and COMSA.
2. DDRAM, CGRAM and symbol register
Their write contents do not change. The contents
are kept regardless of Standby mode selection or
release.
3. The operation mode before selection of Standby
mode is kept.
The internal circuits for dynamic display are
stopped.
4. Oscillator
The oscillator must be turned ON for static display.
• Sleep mode
To select the Sleep mode, turn OFF the power circuit
and oscillator by issuing the command, and clear all
data of Static Icon register to zero. Then, issue the
Power Save command. The system power
consumption will be minimized to almost the stopped
status.
1. LCD display outputs
COM1 to COM16, COMS1, COMS2:
V
DD level
SEG1 to SEG60, SEGS1, 2, 4, 5:
V
DD level
SEGSA, B, C, D, E, F, G, H, I, J, COMSA:
Clear all data of Static
Icon register to zero.
2. DDRAM, CGRAM and symbol register
Their write contents do not change. The contents
are kept regardless of Standby mode selection or
release.
3. The operation mode before selection of Standby
mode is kept.
All internal circuits are stopped.
4. Oscillator
Turn OFF the built-in power supply and oscillator
by issuing the Power Save and power control
commands.
No. Electronic control register XV5
0 (0, 0, 0, 0, 0) 0 Large
1 (0, 0, 0, 0, 1) 1α •
2 (0, 0, 0, 1, 0) 2α •
3 (0, 0, 0, 1, 1) 3α •
•• ••
•• ••
30 (1, 1, 1, 1, 0) n-1α •
31 (1, 1, 1, 1, 1) nα Small
This is reference voltage for the liquid
crystal drive power circuit. The V
REGZ has
a temperature characteristics of about
–0.05%/deg.
V SS
V DD
V REG1
V REG2
V 1
V 3
V 4
V 5
OCA
OCC
OCD
OCB
OCE
SED1225
Note:
Reference set value: (0.1~1.0 µF)
We recommend to display the capacitance
appropriate to the LCD panel size and set
up the capacitance by observing the drive
signal waveforms.