SCI7654C0A EPSON [Epson Company], SCI7654C0A Datasheet - Page 5

• Manufacturer Part Number: SCI7654C0A
• Description: DC/DC Converter
• Manufacturer: EPSON [Epson Company]

FUNCTIONAL DESCRIPTION
Mode
Voltage Converter Circuit
Clock Generator Circuit
Reference Voltage Circuit
As the SCI7654 has a built-in clock generator circuit, it requires no external source at all. The clock rate changes
depending on the FC pin signal level, and the Low Output or High Output mode can be selected. This allows
a frequency selection according to the current capacitance and load current when the booster output impedance
changes depending on the clock rate and external booster capacitance.
The voltage converter receives a clock from the clock generator, and boosts the V
quadruple, triple or double. Four converter circuits are required for quadruple boosting, three converts are
required for triple boosting, and dual converters are required for double boosting.
The SCI7654 has a built-in reference voltage circuit for the voltage regulator. The temperature coefficient of
reference voltage can be changed using pins TC1 and TC2, and a voltage having one of four types of temperature
gradients can be output at V
CT0
CT1
CT2
CT3
H (V
FC pin
L (V
DD
IN
)
)
H(V
L(V
High Output
Low Output
TC1
H
L
DD
IN
Mode
)
)
H(V
double boosting
L(V
REG
TC2
Voltage step-up diagram (during -5V input)
H
L
16.0 kHz (Typ.)
DD
IN
4.0 kHz (Typ.)
pin for LCD driving.
)
Clock Rate
)
10V
triple boosting
Reference Voltage, V
-1.90
-2.15
-1.55
-1.70
Min.
15V
quadruple boosting
Approx. 4 times of I
Current Consumption
Typ.
-1.5
-1.5
-1.5
-1.5
20V
V
(0V)
V
(-5V)
-10V
-15V
-20V
I
DD
IN
OP
REF
-1.45
-1.30
-1.10
-0.85
Max.
(V)
OP
Temperature Coefficient, CT (%/˚C)
-0.07
-0.25
-0.45
-0.75
Min.
SCI7654M
Approx. 1/4 time of V
Output Ripple
IN
input power voltage
-0.04
-0.15
-0.35
-0.55
Typ.
V
RP
0A
-0.07
-0.20
-0.30
Max.
/C
RI
0
0A
5