MP4032-2—OFFLINE LED DRIVER WITH FULLY-INTEGRATED INTERNAL MOSFET

MP4032-2 Rev.1.01

www.MonolithicPower.com

10

10/23/2014

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PIN FUNCTIONS

Pin #

Name

Pin Function

1

COMP

Loop Compensation.

Connects a compensation network to stabilize the LED driver and get

an accurate LED driver current.

2

MULT

Multiplier Input.

Connect this pin to the tap of resistor divider from the rectified voltage of

the AC line. The half-wave sinusoid signal on this pin provides a reference signal for the

internal current control loop.

3

ZCD

Zero Current Detection Input.

A negative going-edge triggers the turn-on signal of the

internal MOSFET. Connect this pin to a resistor divider between the auxiliary winding to

GND. Over-voltage condition is detected through ZCD. For each switching turn-off interval, if

the ZCD voltage exceeds the over-voltage-protection (OVP) threshold after the 1.9μs

blanking time, OVP will trigger and the system will stop switching until auto-restart.

4

VCC

Power Supply Input.

Powers both the control signal and the internal high-voltage MOSFET

gate driver. Bypass to ground with an external bulk capacitor (typically 22μF) to reduce

ripple.

5

GND

Ground.

Current return for the control signal and the gate drive signal.

6

CS

Internal MOSFET Source and Current Sense Input.

Connect a current-sensing resistor

from this pin to GND to set the LED current. Senses the MOSFET current. Comparing the

resulting voltage and the internal sinusoidal-current reference signal determines when the

MOSFET turns off. If the pin voltage exceeds the current limit threshold of 2.24V (after turn-

on blanking) the gate drive will turn off.

7

NC

8

DRAIN

Drain of the Internal MOSFET.

Provides charging current from the rectified AC line voltage

to VCC for start-up.