LC5540LF Datasheet, PDF (1/13 Pages) Sanken electric – Single-Stage Power Factor Corrected Off-Line Switching Regulators

LC5540LF 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
Packages: 7-pin TO-220F
Not to scale
LF 3052
LF 3051
LF 3054
Description
LC5540LF 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 LC5540LF devices are intended for isolated designs.
The incorporated MOSFET has a V_DSS(min) rating from
650 V (LC5546LF and LC5547LF) to 800 V (LC5549LF).
The R_DS(on)(max) is 1.1 Ω (LC5547LF) to 1.9 Ω
(LC5546LF). It is capable of a maximum output power
of 80 W on 230 VAC supply to 55 W on universal supply
(LC5547LF) 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
F1
L1
D1
D2 L2
Typical Application
C11
T1
VAC _C1
D3
D4
C8
R5
C2
D8
PC2
R8 ^R10
U1
L C554x LF
Control
Part
D9
D5
R1
C4
PC2
R6
D6
C9
C10
Q1
R13
R9
PC1 _R11
R12
C13
R17
DZ2
DZ1
-
C12 ^{U2 +}
C17
C14
D/ST S/GND VCC OCP FB NC OVP
12
3 4 567
R14
R15
R18
C15
R16
R19 R20
C3
R2
(Rocp)
C5 C6
R3
R7
R4
PC1
D7
C7
LED
C16
LC5540LF-DS
SANKEN ELECTRIC CO., LTD.