S1F78100Y2A Epson Electronics America, Inc., S1F78100Y2A Datasheet - Page 30

• Manufacturer Part Number: S1F78100Y2A
• Description: High Precision Voltage Regulators
• Manufacturer: Epson Electronics America, Inc.

FUNCTIONAL DESCRIPTIONS
CR Oscillator
S1F76620 has a built-in CR oscillator as the internal os-
cillator, and an external oscillation resistor R
nected between the pins OSC1 and OSC2 before opera-
tion.
Note 1
Since the oscillation frequency varies with wiring ca-
pacitance, make the cables between the terminals OSC1
and OSC2 and R
When setting the external resistor R
able for f
from characteristics graph (9) and (10). The relations
between R
expressed approximately with the following formula as
far as the
straight portion (500k < R
(A : Constant, When GND is 0V and V
approximately 2.0 10
So, the R
(Recommended oscillation frequency : 10kHz to 30kHz
(R
When the external clock operates, make the pin OSC2
open as shown below and input the 50% duty of the ex-
ternal clock from the pin OSC1.
S1F70000 Series
Technical Manual
OSC
: 2M to 680k ))
OSC
OSC
OSC
OSC1
OSC2
that brings about the maximum efficiency
value can be obtained from this formula.
and f
OSC1
OSC2
OSC
R
OSC
OSC
as short as possible.
10
= A • (1/f
Open
in characteristics graph (1) are
(I/F).)
OSC
External clock
< 2M ) is concerned:
OSC
(Note 1)
OSC
R
)
OSC
, find R
DD
is 5V, A is
OSC
OSC
is con-
suit-
EPSON
Voltage Conversion Circuit
The voltage conversion circuit uses clocks generated in
the CR oscillator to double the input supply voltage
V
In case of 2 times step-up, 2 times voltage (2V
the input voltage is obtained from the V
pump up capacitor is connected between CAP1+ and
CAP2– and a smoothing capacitor is connected be-
tween V
When GND is 0 and V
input/output and voltage are as shown below:
DD
.
DD
CAP1=2V
V
G
and V
DD
ND
=5V
=0V
O
outside.
DD
=10V
DD
is 5, the relations between
S1F76620 Series
O
pin when a
DD
1–13
) of