NCP5602

http://onsemi.com

3

PIN FUNCTION DESCRIPTION

Pin No.

Symbol

Function

Description

1

GND

POWER

This pin is the GROUND signal for the analog and digital blocks and must be

connected to the system ground. This pin is the GROUND reference for the

DC−DC converter and the output current control. The pin must be connected

to the system ground, a ground plane being strongly recommended.

2

LED1

INPUT, POWER

This pin sinks to ground and monitors the current flowing into the first LED,

intended to be used in backlight application. The current is limited to 30 mA

maximum (see Note 2). When the ICON bit of the LED−REG register is

High, the LED2 fulfills the ICON function. In this case, LED1 is deactivated.

3

LED2

INPUT, POWER

This pin sinks to ground and monitors the current flowing into the second

LED, intended to be used in backlight application. The current is limited to

30 mA maximum (see Note 2). When the ICON bit of the LED−REG register

is High, the LED2 fulfills the ICON function. In this case, LED1 is

deactivated. The ICON current is 600

mA typical.

4

INPUT, ANALOG

This pin provides the reference current, based on the internal bandgap

voltage reference, to control the output current flowing in the LED. A 1%

tolerance, or better, resistor shall be used to get the highest accuracy of the

LED biases. An external current source can be used to bias this pin to dim

the light coming out of the LED.

In no case shall the voltage at pin 4 be forced either higher or lower than the

600 mV provided by the internal reference.

5

SDA

INPUT, DIGITAL

This pin carries the data provided by the I2C protocol. The content of the

SDA byte is used to program the mode of operation and to set up the output

current (see Table 2).

6

SCL

INPUT, DIGITAL

This pin carries the I2C clock to control the DC−DC converter and to set up

the output current. The SCL clock is associated with the SDA signal.

7

VOUT

OUTPUT, POWER

This pin provides the output voltage supplied by the DC−DC converter. The

Vout pin must be bypassed by 1.0

mF ceramic capacitor located as close as

possible to the pin to properly bypass the output voltage to ground. The

circuit shall not operate without such bypass capacitor properly connected to

the Vout pin.

The output voltage is internally clamped to 5.5 V maximum in the event of no

load situation. On the other hand, the output current is limited to 40 mA

(typical) in the event of a short circuit to ground.

8

C2P

POWER

pin, associated with C2N (see Note 1).

9

C2N

POWER

pin, associated with C2P (see Note 1).

10

C1P

POWER

pin, associated with C1N, pin 11 (see Note 1).

11

VBAT

INPUT, POWER

Input Battery voltage to supply the analog and digital blocks. The pin must be

decoupled to ground by a 1.0

mF ceramic capacitor.

12

C1N

POWER

pin, associated with C1P, pin 10 (see Note 1).

1. Using low ESR ceramic capacitor is mandatory to optimize the Charge Pump efficiency.

2. Total DC−DC output current is limited to 60 mA.