CAT3604_08 Datasheet, PDF (9/12 Pages) Catalyst Semiconductor – 4-Channel Regulated Charge Pump White LED Driver

CAT3604
TYPICAL CHARACTERISTICS
V_IN = 3.6V, EN = V_IN, C_IN = C_OUT = 1µF, unless otherwise specified.
Foldback Current Limiting
5
4
1x mode
3
2
1
0
0 100 200 300 400 500
OUTPUT CURRENT [mA]
RECOMMENDED LAYOUT
When the driver is in the 1.5x charge pump mode, the
1MHz 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 2. 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.
0.65mm
Figure 2. PCB Layout
2.25mm
0.35mm
Figure 3. Recommended QFN 16 Package
Land Pattern
© Catalyst Semiconductor, Inc.
9
Characteristics subject to change without notice
Doc. No. MD-5008 Rev. J