SANKEN ELECTRIC CO., LTD.

http://www.sanken-ele.co.jp/en/

LC5540LD Series

Description

The LC5540LD series is the power IC for the isolated type

LED driver which has an incorporated power MOSFET,

designed for input capacitorless applications, and making it

possible for systems to comply with the harmonics standard

(IEC61000-3-2 class C), even during light load condition.

The controller adapts the average current control method for

realizing high power factors, and the quasi-resonant topol-

ogy contributes to high efficiency and low EMI noise. The

series is housed in DIP8 packages.

The rich set of protection features helps to realize low com-

ponent counts, and high performance-to-cost power supply.

650 V (LC5545LD and LC5546LD) to 800 V (LC5548LD).

(LC5545LD). It is capable of a maximum output power of

20 W on 230 VAC supply to 16 W on universal input supply

(85 to 265 VAC) (LC5546LD) based on the thermal rating.

Note that the maximum output power can be up to 120% to

140% of this value. However, it may be limited in applica-

tions with low output voltage or short duty cycle.

Features and Benefits

• Integrated on-time control circuit (it realizes high power

factor by average current control)

• Integrated startup circuit (no external startup

circuit necessary)

• Integrated soft-start circuit (reduces power stress during

start-up on the incorporated power MOSFET and

output rectifier)

• Integrated bias assist circuit (improves startup

performance, suppresses VCC voltage droop during

operation, and allows use of low-rated ceramic capacitor

on VCC pin)

• Integrated Leading Edge Blanking (LEB) circuit

• Integrated maximum on-time limit circuit

• Protection features:

▫ Overcurrent protection (OCP): pulse-by-pulse

▫ Overvoltage protection (OVP): latched shutdown

▫ Overload protection (OLP): latched shutdown

▫ Thermal shutdown (TSD): latched shutdown

Single-Stage Power Factor Corrected

Off-Line Switching Regulator ICs

Typical Application

Package: 8-pin DIP

Not to scale

C2

C6

C5

D8

+

-

PC1

U2

DZ1

D1

D3

D2

D4

F1

L1

C1

Q1

D5

C4

C3

T1

D6

D7

DZ2

PC2

L2

LED

R1

PC2

D9

R8

R9

R10

R11

R12

R13

R14

R15

R16

R17

R18

R19 R20

R

OCP

R3

R4

R5

R6

VAC

PC1

R7

R21

DZ3

C18

C7

C8

C10

C9

C11

C12

C13

C14

C15

C16

C17

5

1

2

3

D/ST

8

S/GND VCC

Controller

Chip

U1

OVP

OCP

FB

NC

S/GND

LC554xLD

6

4

Applications

• LED lighting fixtures

• LED light bulbs

LC5540LD-DS

January 28, 2013