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SANKEN ELECTRIC CO., LTD.

LC5540LD-DS

Single-Stage Power Factor Corrected

Off-Line Switching Regulator ICs

LC5540LD Series

January 28, 2013

Functional Block Diagram

Functional Block Diagram

Functional Block Diagram

Pin-out Diagram

Pin List Table

Number

Name

Function

1

S/GND

MOSFET source and GND pin for the Control Part

2

VCC

Supply voltage input and Overvoltage Protection (OVP) signal input

3

OCP

Overcurrent Protection (OCP), quasi-resonant signal input, and

Overvoltage Protection (OVP) signal input

4

FB

Feedback signal input and Overload Protection (OLP) signal input

5NF

No function; must be externally connected to S/GND pin with as

short a trace as possible, for stable operation of the IC

6

OVP

Overvoltage Protection (OVP) signal input

7

–

Pin removed

8

D/ST

MOSFET drain pin and input of the startup current

1

2

3

4

8

6

5

D/ST

OVP

NF

S/GND

VCC

OCP

FB

S/GND

TSD

LEB

D/ST

Control Part

STARTUP

Reg

Bias

UVLO

VCC

OCP

OVP

OVP

OSC

OCP

Detection

Bottom

Reg

Control

Feedback

OLP

⑧

①

②

③

④

Drv

FB

⑥

Q

S

R

⑤

NF