S1D15715 Epson Electronics America, Inc., S1D15715 Datasheet - Page 28

• Manufacturer Part Number: S1D15715
• Description: Liquid Crystal Display =lcd Driver
• Manufacturer: Epson Electronics America, Inc.

S1D15715 Series Technical Manual
6.6 Power supply circuit
This power supply circuit is a low power supply consumption circuit that generates voltage required for driving
liquid crystals, which consists of booster, voltage regulator and voltage follower circuits.
The power supply circuit is controlled by power control set command. Using this command, the booster
circuit, the voltage regulator circuit, and the voltage follower circuit can be independently turned ON or OFF.
Consequently, the external power supply and part of internal power supply circuit functions can be used
simultaneously.
Table 8 lists the functions controllable from 3 bits data of the power control set command. And, Table 9 shows
sample combinations of the bits.
6.6.1 Booster circuit
Using the booster circuit, it is possible to Triple/Double boosting of the V
Triple boosting:
Double boosting:
If the potential between V
built in the V
Fig.9 shows the connections and voltage relationships :
22
D2 Booster circuit control bit
D1 Voltage regulator circuit (V regulator circuit) control bit
D0 Voltage follower circuit (V/F circuit) control bit
External power supply alone is
Built-in power supply alone is
If capacitor C
V
pin.
If capacitor C
between CAP2+ and V
and it is output at V
V/F circuits alone are used
V regulator circuit and V/F
DD
, the potential between V
circuits are used
Pins on the booster circuits denote CAP1+, CAP1-, CAP2+, CAP2- pins.
Combinations other than the above cannot be used.
Usage
DD
used
used
1
will prevent the V
1
is inserted between CAP1+ and CAP1-, between CAP2+ and CAP2- and between V
is inserted between CAP1+ and CAP1-, between V
OUT
OUT
pin.
DD
, the potential between V
-V
DD
SS
D2 D1 D0
1
0
0
0
OUT
and V
is 5V±10% and is double boosting, the clamp circuit (approximately 5V)
1
1
0
0
Item
potential from exceeding the absolute maximum rating (10V)
SS
1
1
1
0
is boosted to triple toward the positive side and it is output at V
Booster
circuit
OFF
OFF
OFF
ON
Table 8
Table 9
EPSON
DD
V regulator
and V
circuit
OFF
OFF
ON
ON
SS
is boosted to double toward the positive side
V/F circuit
OUT
OFF
ON
ON
ON
DD
and V
-V
SS
voltage input
V
voltage level.
DD
0
External
to V
, open CAP2-, and jumper
V
V
OUT
DD
V
“1”
ON
ON
ON
0
4
1
1
1
State
booster circuit
Pins on
OPEN
OPEN
OPEN
Used
OFF
OFF
OFF
“0”
OUT
Rev.1.0
OUT
and