www.austriamicrosystems.com/AS3492

1.2

15 - 18

AS3492

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

The fast switching frequency (2MHz) of the AS3492 allows for the use of small SMDs for the external inductor. The

inductor should have low DC resistance (DCR) to reduce the I

ciency.

If a different inductor is chosen, ensure similar DCR values and at least 2.45µH inductance at maximum peak input

current.

PCB Layout Guideline

The high speed operation requires proper layout for optimum performance. Route the power traces first and try to min-

imize the area and wire length of the three high frequency/high current loops:

At the pin GND a single via (or more vias, which are closely combined) connects to the common ground plane. This

via(s) will isolate the DCDC high frequency currents from the common ground (as most high frequency current will flow

between Loop1 and Loop2 and will not pass the ground plane) - see the ‘island’ at the two through ground vias in

Figure 20:

Figure 20. Layout recommendation

Note: If component placement rules allow, move all components close to the AS3492 to reduce the area and length

of Loop1 and Loop2

Table 6. Recommended Inductor

Part Number

L

DCR

Size

Manufacturer

LQM2HPN4R7MGC

4.7µH;

>2.45µH @ 0.5A

160m



2.5x2.0x0.9mm

max height 1.0mm

Murata

www.murata.com

CIG32K1R0SAF

4.57µH;

>2.45µH @ 0.5A

<300m



2.0x1.25x0.9mm

max height 1.0mm

Samsung Electro-

Mechancs

www.sem.samsung.co.kr

  









 





  

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AS3492