Package Markings; Functional Descriptions - Epson Power Supply IC S1F70000 Technical Manual

Timing diagram
V
I1
PWCR
RST

PACKAGE MARKINGS

S1F76310, S1F76380 series device packages use the
following markings.
7 6 3 1

FUNCTIONAL DESCRIPTIONS

Basic Voltage Booster Operation
Tr1 switches ON and OFF at half the frequency of the
clock pulses from the built-in RC oscillator. When the
transistor is ON, the circuit stores energy in L. When it
is off, this energy flows through D to change C.
L
V
I1
GND
S1F70000 Series
Technical Manual
t
pd
Series number
First subcode character
Second subcode character
Code number
D
V
O
Tr1 C
GND
EPSON
Measurement circuit
V
O
R 100 k
PWCR
C
Internal Circuits
CR oscillator
The S1F76310, S1F76380 series use a built-in CR os-
cillator to drive the voltage booster circuit. The circuit
is supplied by V . All circuit components are on-chip
I1
and thus the drive frequency is set internally. To ensure
50% duty, this frequency is twice that used by the volt-
age booster circuit.
When PS is Low, the oscillator is disabled and the chip
is in standby mode.
PS
R
S1F76300 Series
V
O
RST
C
4–13