MP3394—4-STRING, MAX 200mA/STRING WHITE LED DRIVER

MP3394 Rev. 1.07

www.MonolithicPower.com

5

3/21/2013

MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.

© 2013 MPS. All Rights Reserved.

PIN FUNCTIONS

TSSOP16EP

&SOIC16

SOIC20

Name Description

1

1

COMP

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

regulation control loop. Connect a ceramic capacitor from COMP to GND.

2

2

EN

Enable Control Input. Do not let this pin float.

3

3

DBRT

Brightness Control Input. To use external PWM dimming mode, apply a

PWM signal on this pin for brightness control. To use DC input PWM

dimming mode, apply a DC voltage range from 0.2V to 1.2V on this pin

linearly to set the internal dimming duty cycle from 0% to 100%. The MP3394

has positive dimming polarity on DBRT.

4

5

GND

Ground.

5

7

OSC

Switching Frequency Set. Connect a resistor between OSC and GND to set

the step-up converter switching frequency. The voltage at this pin is

regulated to 1.23V. The clock frequency is proportional to the current

sourced from this pin.

6

8

ISET

LED Current Set. Tie a current setting resistor from this pin to ground to

program the current in each LED string. This pin voltage is regulated to

1.23V. The LED current is proportional to the current through the ISET

resistor.

7

9

BOSC

Dimming Repetition Set. This is the timing pin for the oscillator to set the

dimming frequency. To use DC input PWM dimming mode, connect a

capacitor from this pin to GND to set the internal dimming frequency. A saw-

tooth waveform is generated on this pin. To use external PWM dimming

mode, connect a resistor from this pin to GND, and apply the PWM signal on

DBRT pin.

8

10

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.

9

11

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.

10

12

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.

11

13

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.

12

14

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

MP3394 triggers Over Voltage Protection mode.