CAT6243

www.onsemi.com

12

Figure 28. Thermal Resistance vs. PCB Copper Area for 3 mm x 3 mm WDFN Package

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1 oz C.F

2 oz C.F

1 oz Sim

2 oz Sim

Figure 29. Topside Copper Foil Pattern for Heat Dissipation

Close−up of pad area

PCB Layout Top Layer and

connections to heat spreading plane

Design Hints

wide as possible. When the impedance of these traces is high

due to narrow trace width or long length, there is a chance

to pick up noise or cause the regulator to malfunction. Place

external components, especially the input and output

capacitors, as close as possible to the CAT6243, and keep

traces between power source and load as short as possible.