MP3310N—50V, 1.3A, STEP-UP WHITE LED DRIVER WITH TRUE PWM DIMMING
MP3310N Rev.1.0 www.MonolithicPower.com 4
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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 threshold 1.24V,
the switch will be turned off until V
OVP
decrease and kick the hysteresis.
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.
