SIC63616-(Rev. 1.0) NO. P10
3240-0412
Power supply voltage booster/halver circuit
The S1C63616 supports a wide supply voltage (V
DD
) range that exceeds the operating voltage range of
the voltage regulator (LCD system voltage regulator). The power supply voltage booster/halver circuit
generates the V
D2
voltage to drive the voltage regulators when the supply voltage V
DD
is out of the
operating voltage range of the voltage regulators.
Table 2.1.2.2 Relationship between supply voltage V
DD
and voltage regulator operating voltage
Power supply
voltage V
DD
1.6 to 2.5 V
2.5 to 5.5 V
Power source for
LCD system voltage regulator
V
D2
(
≈
V
DD
×
2)
V
DD
When a V
C2
reference voltage option for the LCD drive power supply is selected, the LCD system volt-
age regulator must be driven with a 2.5 V or more operating voltage. Therefore, the LCD system voltage
regulator can be driven with V
DD
if 2.5 V or more supply voltage V
DD
is used. When the supply voltage
V
DD
is less than 2.5 V, drive the power supply voltage booster/halver in boost mode to generate V
D2
and use it to drive the LCD system voltage regulator. The V
D2
voltage generated in boost mode is about
double the V
DD
voltage level.
The V
D2
voltage is not required when the power supply voltage (V
DD
) is within the range from 2.5 V to
5.5 V (1.6 V to 5.5 V when the V
C1
reference LCD drive power option is selected). In this case the power
supply voltage booster/halver can be turned off.
The S1C63616 allows software to control the power supply voltage booster/halver and to select the
power source of the voltage regulator. Refer to Section 4.2, "Power Control", for details.
Internal voltage regulator
The internal voltage regulator generates the operating voltage V
D1
for driving the internal logic circuits
and the OSC3 oscillation circuit.
Oscillation system voltage regulator
The oscillation system voltage regulator generates the V
OSC
voltage for driving the OSC1 oscillation
circuit and is provided separately with the internal voltage regulator to stabilize the oscillation and to
reduce power consumption.
LCD system voltage regulator
The LCD system voltage regulator generates the LCD drive voltages V
C1
to V
C5
. See Chapter 7, "Electri-
cal Characteristics" for the voltage values.
In the S1C63616, the LCD drive voltage is supplied to the built-in LCD driver which drives the LCD
panel connected to the SEG and COM terminals.
Notes: • Be sure not to use the V
D1
, V
D2
, V
OSC
and V
C1
to V
C5
terminal output voltages to drive external
circuits.
• If V
DD
equal to or less than 2.5 V is used as the power source for the LCD system voltage
regulator, the V
C1
to V
C5
voltages cannot be generated within specifications (when a V
C2
reference
voltage option is selected).
• HLON is prohibited from use. Always be sure to set to "0".