4 POWER SUPPLY
4-2
EPSON
S1C17704 TECHNICAL MANUAL
4.2 Internal Power Supply Circuit
The S1C17704 has a built-in power supply circuit shown in Figure 4.2.1 to generate all the power voltages required
for the internal circuits. The power supply module consists of three circuits.
Table 4.2.1 Power Supply Circuit
Circuit
Power supply circuit
Output voltage
Oscillator and internal logic circuits Internal logic voltage regulator
V
D1
LCD system voltage regulator
Power voltage booster
V
DD
or V
D2
LCD driver
LCD system voltage regulator
V
C1
to V
C5
V
D1
V
D2
V
DD
External
power
supply
Oscillation circuit
Internal logic
voltage regulator
Power voltage booster
VD1MD
PBON
Internal circuit
OSC1, OSC2
OSC3, OSC4
V
DD
V
D1
V
D2
CF
CG
V
C1
V
C2
V
C3
V
C4
V
C5
CA
CB
CC
CD
CE
V
SS
LCD driver
COM0–COM31
SEG0–SEG55
VDSEL
HVLD
LCD system
voltage regulator
V
C1
~V
C5
LHVLD
Figure 4.2.1 Configuration of Power Supply Circuit
Note
: Be sure to avoid using the V
D1
, V
D2
, and V
C1
–V
C5
pin outputs to drive external circuits.
Internal logic voltage regulator
The internal logic voltage regulator generates the V
D1
operating voltage for the internal logic circuits and
oscillators. The V
D1
voltage value can be switched in the program; set it to 1.8 V for normal operation and 2.5
V for Flash programming.
Power voltage booster
The power voltage booster generates the V
D2
operating voltage for the LCD system voltage regulator. Either
V
DD
or V
D2
can be selected as the power source for the LCD system voltage regulator according to the V
DD
supply voltage value.
Table 4.2.2 Power Source for LCD System Voltage Regulator
Power supply voltage V
DD
Power source for the LCD system voltage regulator
1.8 to 2.5 V
V
D2
(
≅
V
DD
×
2)
2.5 to 3.6 V
V
DD
LCD system voltage regulator
The LCD system voltage regulator generates the 1/5-bias LCD drive voltages V
C1
, V
C2
, V
C3
, V
C4
, and V
C5
.
In the S1C17704, the LCD drive voltage is supplied to the built-in LCD driver that drives the LCD panel
connected to the SEG and COM pins.
Note
: If V
DD
is used as the power source for the LCD system voltage regulator when V
DD
is 2.5 V or
less, the V
C1
to V
C5
voltages cannot be generated within the specifications.
Summary of Contents for S1C17704
Page 1: ...TECHNICAL MANUAL S1C17704 CMOS 16 BIT SINGLE CHIP MICROCOMPUTER ...
Page 22: ...1 OVERVIEW 1 10 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 42: ...3 MEMORY MAP BUS CONTROL 3 12 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 82: ...6 INTERRUPT CONTROLLER ITC 6 26 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 108: ...8 CLOCK GENERATOR CLG 8 8 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 112: ...9 PRESCALER PSC 9 4 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 138: ...10 I O PORTS P 10 26 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 156: ...11 16 BIT TIMERS T16 11 18 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 208: ...14 8 BIT OSC1 TIMER T8OSC1 14 16 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 234: ...16 STOPWATCH TIMER SWT 16 14 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 242: ...17 WATCHDOG TIMER WDT 17 8 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 264: ...18 UART 18 22 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 300: ...20 I2C 20 20 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 320: ...21 REMOTE CONTROLLER REMC 21 20 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 360: ...24 ON CHIP DEBUGGER DBG 24 6 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 362: ...25 BASIC EXTERNAL WIRING DIAGRAM 25 2 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...