MP1518 – FIXED FREQUENCY WHITE LED DRIVER

MP1518 Rev. 1.6

www.MonolithicPower.com

3

7/25/2006

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© 2006 MPS. All Rights Reserved.

TM

Parameters

Symbol

Condition

Min

Typ

Max Units

Enable

EN Threshold

1.0

1.35

1.6

V

EN Threshold

0.8

V

EN Hysteresis

90

mV

EN Input Bias Current

1

µA

Feedback

FB Voltage

94

104

114

mV

FB Input Bias Current

-600

-300

nA

Output Switch

SW On-Resistance

(4)

0.5

Ω

SW Current Limit

(4)

Duty Cycle = 60%

350

mA

Thermal Shutdown

(4)

160

°C

Notes:

4) Guaranteed by design.

PIN FUNCTIONS

TSOT23-6

Pin #

QFN8

Pin #

Name Pin Function

1

8

SW

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

the power inductor and output rectifier to SW. SW can swing between GND and

25V.

2

1, 5

GND

Ground.

3

6

FB

Feedback Input. The MP1518 regulates the voltage across the current sense

resistor between FB and GND. Connect a current sense resistor from the bottom

of the LED string to GND. Connect the bottom of the LED string to FB. The

regulation voltage is 104mV.

4

4

EN

Regulator On/Off Control Input. A high input at EN turns on the converter, and a

low input turns it off. When not used, connect EN to the input source for

automatic startup. The EN pin cannot be left floating.

5

3

OV

Over Voltage Input. OV measures the output voltage for open circuit protection.

Connect OV to the output at the top of the LED string.

6

2

IN

Input Supply Pin. Must be locally bypassed.