MP3310—50V, 1.3A, STEP-UP WHITE LED DRIVER WITH TRUE PWM DIMMING

MP3310 Rev.1.0

www.MonolithicPower.com

4

7/5/2011

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PIN FUNCTIONS

Pin #

Name

Pin Function

1

OVP

Open Load Protection Programming Pin. Connect a resistor divider from output to this

pin to program the OVP threshold. When this pin voltage reaches the shutdown

threshold 1.24V, the switch will be turned off and latch up until the IC is turned off and

enabled again.

2

ISET

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

whole LED current.

3

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.

4

LED

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

control switch. Connect the LED cathode to this pin. With internal 500mV

reference, the current flows into LED pin should be less than 120mA for normal

operation.

5

GND,

Exposed Pad

Ground. Connect exposed pad to GND plane for proper thermal performance.

6

SW

Power Switch Output. SW is the drain of the internal MOSFET switch. Connect the

power inductor and output rectifier to SW.

7

EN/DIM

ON/OFF Control and Dimming Command Input. To use PWM dimming, add a 200Hz to

2kHz square wave signal to this pin.

8

VIN

Input Supply Pin. Must be locally bypassed.

9

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.

10

FSET

Switching Frequency Programming Pin. Connect a resistor to ground to set the switching

frequency.