LC5540LD Datasheet, PDF (1/11 Pages) Sanken electric – Single-Stage Power Factor Corrected Off-Line Switching Regulators

LC5540LD Series
Single-Stage Power Factor Corrected
Off-Line Switching Regulators
Features and Benefits
• Integrated on-width 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 rectifier)
• Integrated bias assist circuit (improves the startup
performance, suppresses V_CC voltage droop during
operation, allows reduction of VCC capacitor value as well
as use of a ceramic capacitor)
• Integrated Leading Edge Blanking (LEB) circuit
• Integrated maximum on-time limit circuit
• Dual-chip structure, with an avalanche-guaranteed power
MOSFET (allows simplified surge suppressing circuits)
• Protection features:
▫ Overcurrent protection (OCP): pulse-by-pulse
▫ Overvoltage protection (OVP): latched shutdown
▫ Overload protection (OLP): latched shutdown
▫ Thermal shutdown (TSD): latched shutdown
Package: 8-pin DIP
Not to scale
Description
LC5540LD series is a quasi-resonant topology switching
power supply IC, designed for input capacitorless applica-
tions, and making it possible for systems to comply with the
harmonics standard (IEC61000-3-2 class C). It incorporates
separate controller and power MOSFET chips. The control-
ler adapts the average current control method for realizing
high power factors, and the quasi-resonant topology contrib-
utes to high efficiency and low EMI noise. The rich set of
protection features helps to realize low component counts,
and high performance-to-cost power supply.
The LC5540LD devices are intended for isolated designs.
The incorporated MOSFET has a V_DSS(min) rating from
650 V (LC5545LD and LC5546LD) to 800 V (LC5548LD).
The R_DS(on)(max) is 1.9 Ω (LC5546LD) to 3.95 Ω
(LC5545LD). It is capable of a maximum output power
of 20 W on 230 VAC supply to 16 W on universal supply
(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 applications with low
output voltage or short duty cycle.
Applications
• LED lighting fixtures
• LED light bulbs
Typical Application
F1
L1
D1
D2 L2
C11
T1
VAC _C1
D3
D4
C8
R5
C2
D8
PC2
R8 ^R10
C9
C10
Q1
R13
D9
U1
LC554xLD
8
6
D/ST OVP
S/GND
5
NF
D5
R1
C4
C3
PC2
Control
Part
R6
C17
D6
R9
PC1 _R11
R12
C13
R17
DZ2
DZ1
-
C12 ^{U2 +}
C14
R14
R15
R18
C15
R16
R19 R20
S/GND VCC OCP FB
1
2
34
C5
R2
(Rocp)
R3
R7
C6
D7
R4
PC1
C7
LED
C16
LC5540LD-DS
SANKEN ELECTRIC CO., LTD.