MP3384- 50V, 4-STRING WHITE LED DRIVER

MP3384 Rev. 1.01

www.MonolithicPower.com

5

1/29/2013

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PIN FUNCTIONS

Pin #

Name

Description

1

EN

Enable Control Input. Do not let this pin floating.

2

OSC

Switching Frequency Selection Input. When float this pin or connect this pin to VCC, the

step-up converter switching frequency is 1.25MHz. When connect this pin to GND, the

step-up converter switching frequency is 625kHz.

3

ISET

LED Current Setting. Tie a current setting resistor from this pin to ground to program the

4

GND

Analog Ground.

5

PWM

PWM Signal Input. The logic signal on this pin controls the PWM burst mode dimming

frequency and duty cycle.

6

LED1

LED String 1 Current Input. This pin is the open-drain output of an internal dimming control

switch. Connect the LED String 1 cathode to this pin. If this string is not used, connect Vout to

this pin.

7

LED2

LED String 2 Current Input. This pin is the open-drain output of an internal dimming control

switch. Connect the LED String 2 cathode to this pin. If this string is not used, connect Vout to

this pin.

8

LED3

LED String 3 Current Input. This pin is the open-drain output of an internal dimming control

switch. Connect the LED String 3 cathode to this pin. If this string is not used, connect Vout to

this pin.

9

LED4

LED String 4 Current Input. This pin is the open-drain output of an internal dimming control

switch. Connect the LED String 4 cathode to this pin. If this string is not used, connect Vout to

this pin.

10

OVP

Over-voltage Protection Input. Connect a resistor divider from output to this pin to program

the OVP threshold. When this pin voltage reaches 1.23V, the MP3384 triggers OV Protection

mode.

11

NC

No Connect.

12

PGND

Step-up Converter Power Ground. Connect exposed pad to PGND.

13

SW

Step-up Converter Power Switch Output. SW is the drain of the internal MOSFET switch.

Connect the power inductor and output rectifier to SW. SW can swing between GND and

50V.

14

COMP

Step-up Converter Compensation Pin. This pin is used to compensate the regulation control

loop. Connect a capacitor or a series RC network from COMP to GND.

15

VCC

The Internal 5V Linear Regulator Output. VCC provides power supply for the internal

MOSFET switch gate driver and the internal control circuitry. Bypass VCC to GND with a

ceramic capacitor. If VIN is less than 5.5V, apply an external 5V supply directly on VCC.

16

VIN

Supply Input. VIN supplies the power to the MP3384 chip. Drive VIN with a 4.5V to 25V

power source. Must be locally bypassed.