Epson Power Supply IC S1F70000 Technical Manual page 77

S1F76540 Series
Setup conditions of Figure 2.12
• Internal clock : ON (Low Output mode)
• Booster circuit : ON
• Regulator : ON (if C
Figure 2.13 Potential relationship during 6-time boosting using diodes
Power-off procedure
• Set the P pin to low (V
OFF1
Output voltages
• When diodes are used for voltage boosting, the characteristics of diodes directly affect on the voltage boosting
characteristics. The forward voltage drop (V
of Figure 2.12 uses two diodes, the drop of "V
booster output voltage is expressed by equation (5).
To increase the |V
O
| V ' | = 6 | V
O
Notes
1 Input and output current conditions
To satisfy the input and output current ratings, limit the total current does not exceed the rated input current.
The total current means the total boost time multiplied by the output load current. The example of Figure 2.12
has the maximum load current of 13.3 mA ( = 80 mA divided by 6).
2 Input and output voltage conditions
To satisfy the input and output voltage ratings, take care not to violate the electric potential relationship of
higher time boosting using diodes. The example of Figure 2.12 must have the "V
voltage conditions during 6-time boosting (see Table 2.3).
Application in other setup conditions
1 When used in the High Output mode
Connect the FC pin to the V
2 When changing the temperature coefficient (C
Change the TC1 and TC2 pin setup by following the definition of Table 2.7.
2–34
= –0.04%/ C)
T
V
DD
V
I
V
I
4V
I
V
O
) to turn off all circuits.
I
'| value, use the diodes having a smaller V
| – 2 V
I F
pin.
I
6V
I
6V
I
2 V
F
) of diodes can reduce the booster output voltage. As the example
F
" voltage multiplied by two occurs as shown in Figure 2.13. The
F
.
F
)
T
EPSON
– (2 V )
F
V '
O
• • • • Equation (5)
" that can satisfy the input
I
S1F70000 Series
Technical Manual