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AS1341

Data Sheet - A p p l i c a t i o n I n f o r m a t i o n

9 Application Information

Adjusting Output Voltage

The AS1341 feedback input features dual-mode operation. Connect FB to GND for the 5.0V preset output voltage.

Adjust the output voltage by connecting a voltage-divider from the output to GND (Figure 4).

Figure 22. Adjustable Output Voltage Circuit

Ω.

Where:

Setting Current Limit

The AS1341 adjustable peak current limit is set by connecting ILIMIT as shown in Table 4.

The current limit chosen should reflect the maximum load current. The maximum output current is half of the peak cur-

rent limit. Choosing a lower current limit allows using an inductor with a lower current rating, however, it requires a

higher inductance (see Inductor Selection on page 10) and does not allow for reduced inductor package size.

Inductor Selection

The AS1341 operates with a wide range of inductance values. For most applications, values between 10µH and 47µH

work best with the controller’s high switching frequency. Larger inductor values will reduce the switching frequency and

thereby improve efficiency and EMI.

Note: The four key factors in inductor selection are inductance value, saturation rating, series resistance, and size.

Table 4. Setting Peak Current Limit

Current Limit

ILIMIT Connected To

700mA

GND

1400mA

IN

4.5 to

20V

5

IN

7

SHDNN

4

LX

8

OUT

1.25V

2

GND

6

ILIMIT

1

FB

D1

L1

+

Indicates High-Power Trace

AS1341

3

POK

(EQ 2)

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1

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