Epson S1F70000 User Manual

S1F70000 Series

2–11

Technical Manual

The on-chip CR oscillator network frequency is deter-
mined by the external resistor, R

OSC

, connected be-

tween OSC1 and OSC2. This oscillator can be disabled
in favor of an external clock by leaving OSC2 open and
applying an external clock signal to OSC1.

OSC1

Oscillator

External clock

External clock

signal

R

OSC

OSC2

OSC1

OSC2

The reference voltage generator supplies a reference
voltage to the voltage regulator to control the output.
This voltage can be switched ON and OFF.

V

DD

V

REG

R

RV 

= 100 k

Ω

 to 1 M

Ω

RV

P

OFF

Control signal

The voltage multiplier uses the clock signal from the
oscillator to double or triple the input voltage. This re-
quires three external capacitors–two charge-pump ca-
pacitors between CAP1+ and CAP1– and CAP2+ and
CAP2–, respectively, and a smoothing capacitor be-
tween V

I

 and V

O

.

C4

R1

R2

+

10 

µ

F

V

REG

 = –8 V

V

I

 = –5 V

R

RV

100 k

Ω

to

1 M

Ω

R

OSC

1 M

Ω

C1

+

10 

µ

F

C2

5 V

+

10 

µ

F

C3

+

10 

µ

F

V

O

 = –15 V

V

DD

 = 0 V

14

13

12

11

10

9

8

1

2

3

4

5

6

7

V

CC

(+5V)

GND

(–5V)

V

DD 

= 0 V

V

I 

= –5 V

V

CAP2 

– = 2V

I 

= –10 V

V

DD 

= 0 V

V

I 

= –5 V

V

O 

= 3V

I 

= –15 V