CAT3616

Doc. No. 5018 Rev. A

8

Characteristics subject to change without notice

PIN DESCRIPTIONS

Pin #

Name

Function

1

MAIN1

MAIN1 LED cathode terminal (if not used, connect to VOUT)

1

2

ENM

¯¯¯

Enable main LED (MAIN1 to MAIN4) input. Active low

3

ENS

¯¯¯

Enable sub LED (SUB1, SUB2) input. Active low

4

EN

Device enable input. Active high.

5

VOUT

Charge pump output connected to the LED anodes

6

VIN

Supply voltage.

7, 8

C1-, C1+

Bucket capacitor 1 terminal

9, 10

C2-, C2+

Bucket capacitor 2 terminal

11

GND

Ground reference

12

SUB2

SUB2 LED cathode terminal (if not used, connect to VOUT)

1

13

SUB1

SUB1 LED cathode terminal (if not used, connect to VOUT)

1

14

MAIN4

MAIN4 LED cathode terminal (if not used, connect to VOUT)

1

15

MAIN3

MAIN3 LED cathode terminal (if not used, connect to VOUT)

1

16

MAIN2

MAIN2 LED cathode terminal (if not used, connect to VOUT)

1

TAB

TAB

Connect to Ground on PCB

Note:

(1) MAIN1 to MAIN4, SUB1, SUB2 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

1

µF ceramic bypass capacitor is required between the

VIN pin and ground near the device. The operating

input voltage range is up to 5.5V. When the input

supply falls below the undervoltage threshold (2V), all

LED channels are disabled.

EN is the enable logic input. Logic level for high and

low are set at 1.3V and 0.4V respectively. When EN is

initially taken high, the device becomes enabled and

all LED currents remain at 0mA. To place the device

into zero current shutdown mode, the EN pin must be

held low for 1.5ms or more.

ENM

logic inputs for respectively main and sub LED

channels. The falling edge of the first pulse applied to

ENM

main and sub LED channels to their full scale of

31mA. On each consecutive falling edge of the pulse

applied to ENM

decreased by 1mA step. On the 32

current is set to zero. The next pulse resets the

current back to the full scale of 31mA.

VOUT is the charge pump output that is connected to

the LED anodes. A small 1

µF 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.

MAIN1-4, SUB1-2 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 six LEDs, the 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.