LC5555LD Datasheet, PDF (1/11 Pages) Sanken electric – Single-Stage Power Factor Corrected High Efficiency Non-Isolated Buck LED Driver

LC5550LD Series
Single-Stage Power Factor Corrected
High Efficiency Non-Isolated Buck LED Driver
Features and Benefits
• PWM and quasi-resonant topology
• Integrated on-time control circuit (it realizes high power
factor by average current control)
• 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 V_CC 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
Description
LC5550LD series are PWM and quasi-resonant topology
non-isolated buck LED driver ICs. They incorporate sepa-
rate controller and power MOSFET chips, and are designed
for input capacitorless applications. The controller adapts
the average current control method for realizing high power
factors. The rich set of protection features helps to realize
low component counts, and high performance-to-cost power
supply.
Applications
• LED lighting fixtures
• LED light bulbs
Not to scale
Typical Application
R1
D6
D3
D4
VAC
D1
D2
5
NF
6
ISENSE
U1
LC5550LD
COMP
4
3 ^OCP/BD
2 ^VCC
D/ST
8
1 ^S/GND
C1
R2
C3 C4 C5 C6
C2
R3
R5
R4
D5
T1
C7 R6
LED
LC5550LD-DS
SANKEN ELECTRIC CO., LTD.
July 9, 2012