S1D12200 Epson Electronics America, Inc., S1D12200 Datasheet - Page 163

• Manufacturer Part Number: S1D12200
• Description: S1d12000 Series Lcd Driver Ic Technical Manual Technical Manual
• Manufacturer: Epson Electronics America, Inc.

S1D12304/12305 Series
The contrast control register controls the liquid crystal
driving voltage (V
tronic volume control register set command that adjusts
the contrast of the liquid crystal display (see section 1-
22).
[An exemplary constant setting when the electronic volume control function is being used]
(1)
(2)
(3)
(4)
5–14
Voltage Regulation Circuit Using Electronic Contrast
Control Register
Determining the V
Determinig the R
Determining the R
Regulating the R
Set the electronic volume control register to (D3, D2, D1, D0) = (1, 0, 0, 0) or (0, 1, 1, 1) before matching the R
value to the optimum contrast.
Since I
dispersion range during manufacture. Meanwhile, the temperature dependency of I
Determine the R
temperature.
When using the electronic volume control function, in order to compensate the V
and I
with each IC chip.
When the electronic volume control function is not being used, set the electronic volume control register to (0, 0,
0, 0) using the RES signal or the electronic volume control register setting command.
V
Liquid crystal driving voltage V
V
R
R
5
5
b
a
REF
variable voltage range: 2V
= (1 +
R
R
= V
= 2V/3.65 A
= 548K
=
=
= 585K
REF
c
I
, use a variable registor as Ra and perform optimum contrast adjustment according to the above item (4)
=
=
(V
(6V - 3.1V) / 548K
5
I
is a simplified constant voltage source, fluctuations upto
V
R
R
REF
5
variable voltage range/ I
R
R
5
a
R
voltage setting max - V
a
). This is accomplished by an elec-
b
c
+ R
) • V
a
R
a
3.1V
b
and R
I
I
a
5
REG
voltage setting range by the electronic volume control
b
·····················
V
for the using LCD panel in consideration of the above dispersion and the variation by the
REG
5
: max. -6v ~ min. -8V
REF
REG
2
) / R
b
(Use absolute values for V
EPSON
The commands provide 4-bits of voltage level data to the
electronic volume control register. This provides for the
selection of 16 different voltage levels for the liquid
crystal driving voltage. When using the electronic vol-
ume control function, it is necessary to close the voltage
regulation circuit using electronic control commands.
For reference information, when the electronic volume
control registor value is at (1, 1, 1, 1), the constant current
value becomes: I
V
R
R
a
V
0
I
REF
40% must be taken into consideration, as a
REG
REF
R
=
b
V
and V
REG
3.65 A.
5
Fig. 9
voltage for dispersion of V
REF
5
+
-
voltage settings.)
is :
I
REF
V
DD
=
-0.037 A/ C.
Rev. 2.4
REG
V
a
5