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Revision 1.07

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AS1323

Datasheet - Application In form atio n

9 Application Information

Figure 21. Typical Application

9.1 Inductor Selection

The control scheme of the AS1323 allows for a wide range if inductor values. A 10µH inductor should be sufficient for most applications (see

Figure 21).

Smaller inductance values typically offer smaller physical size for a given series resistance, allowing the smallest overall circuit dimensions.

Applications using larger inductance values may startup at lower battery voltages, provide higher efficiency and exhibit less ripple, but they may

For maximum output current, the inductor value should be chosen such that the controller reaches the current-limit before the maximum on-time

is triggered:

The inductor’s incremental saturation current rating should be greater than the peak switching current. However, it is generally advisable to bias

the inductor into saturation by as much as 20%, although this will slightly reduce efficiency.

9.2 Maximum Output Current

η) as indicated in the formula for

AS1323

3

SHDNN

1

VBATT

4

VOUT

5

LX

10

µF

2

VSS

10

µF

10µH

L

⋅

--------------------------------

>

(EQ 1)

⋅

L

--------------------------------

=

(EQ 2)

1

2

-----------------

⎝⎠

⎛⎞ η

⋅⋅

⋅

=

(EQ 3)