CAT3604A

http://onsemi.com

9

TYPICAL CHARACTERISTICS

Figure 21. Foldback Current Limiting

OUTPUT CURRENT (mA)

500

400

300

200

100

0

0

1

2

3

4

5

1x Mode

Recommended Layout

When the driver is in the 1.5x charge pump mode, the

1 MHz switching frequency operation requires to minimize

trace length and impedance to ground on all 4 capacitors. A

ground plane should cover the area on the bottom side of the

PCB opposite to the IC and the bypass capacitors.

Capacitors Cin and Cout require short connection to ground

which can be done with multiple vias as shown on Figure 22.

A square copper area matches the QFN16 exposed pad

(GND) which is connected by a trace to the pin 12 pad

(GND). A large via (metalized hole) centered in the square

pad provides a low impedance connection to the ground

plane on the opposite side of the PCB and allows the heat

dissipated by the driver IC to spread out resulting in

excellent thermal performance.

2.25 mm

0.35 mm

0.65 mm

Figure 22. PCB Layout

Figure 23. Recommended QFN 16

Package Land Pattern