MP3386- 50V, 6 STRINGS WHITE LED DRIVERS

MP3386 Rev. 1.0

www.MonolithicPower.com

5

1/19/2012

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© 2012 MPS. All Rights Reserved.

PIN FUNCTIONS

QFN24

Pin #

SOIC28

Pin #

Name

Description

1

5

EN

Enable Control Input. Do not let this pin floating.

2

6

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

7

FSET

Dimming PWM Frequency Set. Connect a capacitor between FSET and GND to

DPWM is recommended to be set from 100Hz to 2kHz.

4

8

PWMO

PWM Filter Output. To use external PWM dimming mode, connect a capacitor

between PWMO and GND to form a low-pass filter with an internal 400kΩ

resistor. It filters the external PWM logic signal on PWMI pin into a DC signal

whose level is inversely proportional to the duty-cycle of the input PWM signal

and then the DC signal is translated into a duty-cycle of the dimming PWM. To

use DC input PWM dimming mode, directly apply a DC voltage from 0.2V to

1.2V on PWMO pin for dimming PWM duty cycle control. The DC input PWM

dimming polarity is negative.

5

9

GND

Analog Ground.

6

10

PWMI

PWM Signal Input. To use external PWM dimming mode, apply a PWM signal

on this pin for brightness control. This signal is filtered and its duty cycle is

converted into a DC signal to calculate the DPWM duty cycle. And the DPWM

duty cycle equals to the input PWM duty cycle. To use DC input PWM dimming

mode, float this pin.

7

11

LED6

LED String 6 Current Input. This pin is the open-drain output of an internal

dimming control switch. Connect the LED String 6 cathode to this pin. If this

string is not used, connect Vout to this pin.

8

12

LED5

LED String 5 Current Input. This pin is the open-drain output of an internal

dimming control switch. Connect the LED String 5 cathode to this pin. If this

string is not used, connect Vout to this pin.

9

13

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

14

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.

11

16

ISET

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

12

18

LED2

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.

13

19

LED1

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.

14

15, 17,

20, 25,

27

NC

No Connection.

15

21

Vout

Voltage Output. Connect this pin to output.