CAT3606

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

Figure 22. RSET Pin Voltage vs. Temperature

−50

−25

0

25

50

75

100

125

1.16

1.18

1.20

1.22

1.24

Figure 23. PWM Dimming at 1 kHz on ENM and ENS

50mA/div

Current

Tot. LED

1V/div

VOUT

ENM & ENS

5V/div

200 msec/div

TEMPERATURE (°C)

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 24.

A square copper area matches the QFN16 exposed pad

(GND) and must be connected to the ground plane

underneath. The use of multiple via will improve the heat

dissipation.

Figure 24. PCB Layout