S1F76540 Series

◊Output voltages

•When diodes are used for voltage boosting, the characteristics of diodes directly affect on the voltage boosting characteristics. The forward voltage drop (VF) of diodes can reduce the booster output voltage. As the example of Figure 2.14 uses three diodes, the drop of “V F” voltage multiplied by three occurs. The booster output voltage is expressed by equation (5).

To increase the VO' value, use the diodes having a smaller VF.

VO' = 3× VI – (3× VF)

• • • • Equation (6)

◊Notes

1 Input and output current conditions

To satisfy the input and output current ratings, take care to limit the input current below the ratings.

2Input and output voltage conditions

During forward voltage conversion, the input voltage ratings are the same as two-time negative voltage boost- ing (see Table 2.3).

◊Application in other setup conditions

When used in the High Output mode, connect the FC pin to the VI pin.

Wiring Example When Changing the Regulator Temperature Coefficient

The temperature coefficient of the regulator depends on the temperature coefficient of the internal reference

voltage. To set another temperature coefficient, use a thermistor resistor or others as shown in Figure 2.16.

CO

+

VREG

 

CREG

1

VO

C2P 16

+

 

+

 

 

 

RP

 

 

 

 

R1

R2

2

VRI

C2N 15

C2

 

RT

 

 

 

 

 

 

3

VREG

C3N 14

 

C3

 

 

4

RV

C1N 13

C1

 

 

 

 

 

 

+

 

 

5

 

 

+

 

 

VDD

C1P 12

 

 

 

 

 

VDD

 

6

FC

VI 11

 

 

 

 

 

 

 

+

7

TC1

POFF1 10

 

 

CI

 

8

TC2

POFF2 9

 

 

 

 

 

 

 

 

VI

Figure 2.16 Wiring example when changing the regulator temperature coefficient

2–36

EPSON

S1F70000 Series Technical Manual