CAT3603

7

Doc. No. 5017 Rev. C

Characteristics subject to change without notice

PIN DESCRIPTIONS

Pin #

Name

Function

1

LED1

LED1 cathode terminal (if not used, connect to VOUT)

(1)

2

LED2

LED2 cathode terminal (if not used, connect to VOUT)

(1)

3

LED3

LED3 cathode terminal (if not used, connect to VOUT)

(1)

4

RSET

The LED output current is set by the current sourced out of the RSET pin

5

EN

Device enable (active high)

6

VOUT

Charge pump output connected to the LED anodes

7

VIN

Supply voltage

8

C1+

Bucket capacitor 1 terminal

9

C1-

Bucket capacitor 1 terminal

10

C2-

Bucket capacitor 2 terminal

11

C2+

Bucket capacitor 2 terminal

12

GND

Ground Reference

TAB

Connect to GND on the PCB

Note:

(1) LED1, LED2, LED3 pins should not be left floating. They should be connected to the LED cathode, or tied to VOUT pin if not used.

PIN FUNCTION

VIN is the supply pin for the charge pump. A small

1µF ceramic bypass capacitor is required between the

VIN pin and ground near the device. The operating

input voltage range is from 3.0V to 5.5V.

EN is the enable control logic input for all LED

channels. Guaranteed levels of logic high and logic

low are set at 1.3V and 0.4V respectively.

RSET pin is regulated at 1.2V. An external resistor

RSET connected from the RSET pin to GND sets the

LED current.

VOUT is the charge pump output that is connected to

the LED anodes. A small 1µF ceramic bypass

capacitor is required between the VOUT pin and

ground near the device.

GND is the ground reference for the charge pump.

The pin must be connected to the ground plane on the

PCB.

C1+, C1- are connected to each side of the 1µF

ceramic bucket capacitor C1.

C2+, C2- are connected to each side of the 1µF

ceramic bucket capacitor C2.

LED1 to LED3 provide the internal regulated current

for each of the LED cathodes. These pins enter a high

impedance, zero current state whenever the device is

placed in shutdown mode. In applications using less

than three LEDs, all unused channels should be wired

directly to VOUT. This ensures the channel is

automatically disabled dissipating less than 200µA.

TAB is the exposed pad underneath the package. For

best thermal performance, the tab should be soldered

to the PCB and connected to the ground plane.