LC554XLD Datasheet, PDF (1/11 Pages) Sanken electric – Single-Stage Power Factor Corrected Off-Line Switching Regulator ICs

LC5540LD Series
Single-Stage Power Factor Corrected
Off-Line Switching Regulator ICs
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
Package: 8-pin DIP
Not to scale
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.
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 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.
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
L C554x LD
8
6
D/ST OVP
S/GND
5
NC
D5
R1
C4
C3
PC2
Controller
Chip
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
R_OCP
R3
R7
R21 C18 DZ3 ^R4
C6
PC1
D7
C7
LED
C16
LC5540LD-DS
SANKEN ELECTRIC CO., LTD.
http://www.sanken-ele.co.jp/en/
January 28, 2013