MP4012 ─ HIGH-VOLTAGE, HIGH-CURRENT ACCURACY WLED CONTROLLER

MP4012 Rev. 1.12

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10/12/2013

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PIN FUNCTIONS

Pin #

Name

Pin Function

1

VIN

Input Supply Pin. It is the input of internal linear regulator. Must be locally bypassed.

2

VDD

The Internal Linear Regulator Output Pin. VDD provides power supply for the external

MOSFET gate driver and the internal control circuitry. Bypass VDD to GND with a 0.47μF

or larger ceramic capacitor.

3

GATE

External MOSFET Gate Driver Pin.

4

GND

Ground.

5

CS

Switch Current Sense Input Pin. It is used to sense the current of the external power FET.

It has a built-in 100ns (min) blanking time.

6

SL

Slope Compensation Pin for current sense. Connecting a resistor between SL and GND

programs the slope compensation. In case of constant off-time mode of operation, slope

compensation is unnecessary and let this pin open.

7

RT

Switching frequency/off-time set Pin. A resistor connected between this pin and

GND/GATE sets the frequency/off-time.

8

SYNC

Synchronization Pin. Connecting the multiple MP4012 SYNC pins together to achieve the

synchronous working mode.

9

CL

Current Limit Set Pin. This pin sets the external MOSFET current limit. The current limit

can be set by using a resistor divider from the REF pin to GND.

10

REF

Reference Output Pin. A 0.1μF or larger ceramic capacitor should be connected to bypass

this pin to GND.

11

FAULT

Fault Indication Output Pin. This pin is pulled down to GND in case of short circuit

condition or over voltage condition. It is also used to drive the external MOSFET to

disconnect the load from Vin for boost converter.

12

OVP

Over Voltage Protection Input Pin. Connect a resistor divider from output to this pin to

program the OVP threshold. When the voltage of this pin reaches 4.95V, the MP4012

triggers over voltage protection.

13

PWM

PWM Dimming Input Pin. Apply a PWM signal on this pin for brightness control. The

GATE is disabled when PWM signal is low. The GATE is enabled when PWM signal is

high.

14

COMP

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. COMP pin is also used

for hiccup timer. At IC start up, short protection or over voltage protection, the 5uA current

source charges COMP pint until 5V, and then the 5μA current source discharges COMP

voltage. IC is active when COMP voltage reduces to 1V.

15

ISET

LED Current Set Pin. Connect a resistor divider from REF pin to set the LED current

reference. The analog dimming function can be achieved through adjusting the voltage on

ISET pin.

16

FB

Feedback Input Pin. Connect a current sense resistor from FB to GND. The MP4012

regulates the voltage across the current sense resistor. The regulation voltage is set by

ISET pin.