S1D1 Epson Electronics America, Inc., S1D1 Datasheet - Page 138

• Manufacturer Part Number: S1D1
• Description: LCD Controller-driver With Built-in Character ROM
• Manufacturer: Epson Electronics America, Inc.

(V
S1D15300 Series
Booster circuit
If capacitors C1 are inserted between CAP1+ and CAP1-, between
CAP2+ and CAP2-, CAP1+ and CAP3- and VSS and VOUT, the
potential between VDD and VSS is boosted to quadruple toward the
negative side and it is output at VOUT.
For triple boosting, remove only capacitor C1 between CAP+1 and
CAP3- from the connection of quadruple boosting operation and
jumper between CAP3- and VOUT. The triple boosted voltage
appears at VOUT (CAP3-).
V
it is constant and V
V
variable resistor between V
of R1 and R3 constant resistors and R2 variable resistor is
recommended for fine-adjustment of V
Setup example of resistors R1, R2 and R3:
When the Electronic Volume Control Function is OFF (electronic
volume control register values are (D4,D3,D2,D1,D0)=(0,0,0,0,0)):
V
5–14
Voltage regulator circuit
The boosting voltage occurring at V
V
REG
REG
5
CC
5
voltage can be determined by the following equation when resistors Ra and Rb (R1, R2 and R3) are adjusted within the range of |V5| < |V
=
(GND) V
=+5V) V
=V
(As I
• R1 + R2 + R3 = 5M ................................
• Variable voltage range by R2 V
is the constant voltage source of the IC, and in case of Type 1,
( 1 + R3 + R2 – R2)
Ra
Rb
(Determined by the current passing between V
(Determined by the LCD characteristics)
SS
Potential during double boosting
REF
R1
R2
R3
(V
SS
R1 + R2
DD
R2 = O , V
DD
= 0 A)
=-5V
V
=0V
OUT
basis). To adjust the V
V
REG
VR I
5
=2V
=(1+
=(1+
. =
+I
.
–2.55 V (if V
SS
R2
REF
REF
REG
R
V
R3+R2- R2
Rb
Ra
=-10V
, V
REG
R1+ R2
V
· (R3+R2- R2)
= –2.55V
) V
DD
REG
and V
REG
OUT
.......................
DD
+
-
+I
5
5
) V
is sent to the voltage regulator and the V
is 0 V), In case of Type 2,
REF
voltage.
as shown. A combination
5
5
= –6 to –10 V
output voltage, insert a
REG
· Rb
1
2
DD
V
V
SS
V
V
DD
and V
DD
5
=-5V
V
=0V
Potential during triple boosting
OUT
5
EPSON
=3V
)
SS
=-15V
For double boosting, remove only capacitor C1 between CAP2+ and
CAP2- from the connection of triple boosting operation, open
CAP+2 and jumper between CAP2- and VOUT (CAP3-). The
double boosted voltage appears at VOUT (CAP3-, CAP2-).
For quadruple boosting, set a VSS voltage range so that the voltage
at VOUT may not exceed the absolute maximum rating.
As the booster circuit uses signals from the oscillator circuit, the
oscillator circuit must operate.
Subsection 10.1.1 gives an external wiring example to use master
and slave chips when on-board power supply is active.
From equations
The voltage regulator circuit has a temperature gradient of
approximately -0.2%/ C as the V
temperature gradient, use the Electronic Volume Control Function
for software processing using the MPU.
As the V
lines must be protected from a noise interference.
Voltage regulator using the Electronic Volume Control
Function
The Electronic Volume Control Function can adjust the intensity
(brightness level) of liquid crystal display (LCD) screen by command
control of V
This function sets five-bit data in the electronic volume control
register, and the V
voltages.
To use the Electronic Volume Control Function, issue the Set Power
Control command to simultaneously operate both the voltage
regulator circuit and voltage follower circuit.
Also, when the boosting circuit is off, the voltage must be supplied
from V
When the Electronic Volume Control Function is used, the V
voltage can be expressed as follows:
V
The increased V
of the IC. (For 32 voltage levels, I
5
= (1 +
R1=1.27M
R2=0.85M
R3=2.88M
5
OUT
liquid crystal display (LCD) driver voltage is output. This
R
Rb
Ra
pin has a high input impedance, the shielded and short
To obtain V
To obtain V
terminal.
5
Variable voltage range
R2 = R2, V
) V
LCD driver voltage.
R2 + R3 = 2.92
1.35
5
2
REG
voltage is controlled by use of I
,
5
3
LCD driver voltage can be one of 32-state
+ Rb
and
(R1 + R2) = R3 ..................
5
5
REG
V
= -10 V, from equation
= -6 V, from equation
V
4
SS
DD
Potential during quadruple boosting
:
= –2.55V
=-3V
V
=0V
I
OUT
REF
REG
R1 .....................
=3V
........................
REF
voltage. To obtain another
SS
= I
=-12V
REF
/31)
REF
1
1
:
:
3
4
5
current source
Rev.1.4
OUT
|.
5