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External component setting procedure

(1) Setting of output L constant

of the coil.

shown below.

Furthermore, since the coil L value may also vary by approximately ±30%, set this value with an adequate margin. If the

setting of coil value in the range of 4.7 μF to 100 μF.

(2) Setting of output Co constant

whichever larger for the capacitor. The output ripple voltage can be obtained according to the formula shown below.

Design the component so that this constant will fall within the allowable ripple voltage.

However, 10 μsec will be the estimated value of the DC/DC converter response speed.

Make setting of capacitance with thorough consideration given to the margin so that these two values will fall into the

specified values. It is recommended to make setting of the capacitance in the range of 10 μF to 100 μF. if a short circuit

occurs, an inverse current passes through the parasitic diode to cause damage to the internal circuits. To prevent that,

insert a backflow prevention diode.

Step-down

[A] . . . (1.1)

1

f

1

L

,where f: Switching frequency

,where f: Switching frequency

Step-down

[V]

¥

¥

1

f

[V]

DI

Adjust so that (IOMAX +

not conflict with the rating.

t

Fig.22

Fig.23

L