Epson Power Supply IC S1F70000 Technical Manual page 71

S1F76540 Series
Power-off Control Function
The S1F76540 has the power-off function and turns on
or off each circuit function when control signals are en-
tered in the P and P
OFF1
tem (such as microprocessor) as defined on Table 2.7.
This power-off function can also cut the reactive current
Table 2.7 Available combination of power-off control
P
OFF1
(High = V ) (High = V
DD
Mode (Low = V ) (Low = V
I
PS1 High
PS2 Low
PS3 High
PS4 Low
*1 When the booster circuit is off, approximately V
*2 When the regulator is off, the V
Application notes on power-off function:
• When using external system signals for power-on control, start to control the power only when V
becomes stable after power-on. Unstable V
V
I
P
OFF1
P
OFF2
2–28
pins from an external sys-
OFF2
P
OFF2
) Oscillator Booster Regulator
DD
)
I
Low ON
Low OFF
High OFF
High ON
pin becomes high-impedance state.
REG
Figure 2.6 Start timing of power-off control
in parallel connection and other application circuits.
To use the dual-state, power-off control (all ON and all
OFF states) only, connect pin P
only pin P
OFF1
Functions
circuit circuit
ON ON
OFF (*1) OFF (*2) All circuits are turned off.
ON ON
ON OFF
+ 0.6 V voltage appears at V
I
voltage may destroy the IC permanently during on/off control.
I
V
I
P
OFF1
P
OFF2
EPSON
OFF2
for power-off control.
Applications
All circuits are turned on.
Slave unit side of parallel connection
(Booster and regulator)
Master unit side of parallel
connection (Booster only)
pin.
O
to pin V and use
I
voltage
I
S1F70000 Series
Technical Manual