ICOLL

V+

VAC

+

+

1

2

3

4

5

6

7

8

9

10

-

VLED

GND

VCC

FILTER

NC

NC

ISNS

GATE

NC

COFF

NC

LM3444

VLED-

D3

C7

C9

C10

D4

D8

D9

R2

D1

Q1

C5

C12

D2

D10

Q2

L2

Q3

R3

R4

C11

C4

U1

VBUCK

BR1

LINE VOLTAGE (VAC)

95.0

90.0

85.0

80.0

75.0

80

90

100

110

120

130

140

14 Series connected LEDs

10 Series connected LEDs

Product

Folder

Sample &

Buy

Technical

Documents

Tools &

Software

Support &

Community

LM3444

SNVS682D – NOVEMBER 2010 – REVISED DECEMBER 2015

LM3444 AC-DC Offline LED Driver

1 Features

3 Description

The LM3444 is an adaptive constant off-time AC/DC

1

•

Application Voltage Range: 80 VAC to 277 VAC

buck (step-down) constant current controller that

•

Capable of Controlling LED Currents

provides a constant current for illuminating high

Greater than 1 A

power

LEDs.

The

high-frequency

capable

architecture allows the use of small external passive

•

Adjustable Switching Frequency

components. A passive PFC circuit ensures good

•

Low Quiescent Current

power factor by drawing current directly from the line

•

Adaptive Programmable Off-Time Allows for

for most of the cycle, and provides a constant positive

Constant Ripple Current

voltage to the buck regulator. Additional features

include thermal shutdown, current limit and VCC

•

Thermal Shutdown

undervoltage lockout. The LM3444 is available in a

•

No Flicker at 120 Hz

low profile 10-pin VSSOP package or an 8-lead SOIC

•

Low-Profile 10-Pin VSSOP Package

package.

or 8-Lead SOIC Package

Device Information(1)

•

Patented Drive Architecture

PART NUMBER

PACKAGE

BODY SIZE (NOM)

2 Applications

VSSOP (10)

3.00 mm × 3.00 mm

LM3444

SOIC (8)

3.91 mm × 4.90 mm

•

Solid State Lighting

•

Industrial and Commercial Lighting

(1) For all available packages, see the orderable addendum at

the end of the data sheet.

•

Residential Lighting

SPACE

Typical LM3444 LED Driver Application Circuit

Efficiency vs Line Voltage

1

An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,

intellectual property matters and other important disclaimers. PRODUCTION DATA.