Description
The LC5546AD and LC5546LD are isolated LED
drivers in which a power MOSFET and a control IC are
highly integrated.
The IC provides the systems that can comply with the
harmonics standard (IEC61000-3-2 Class C) in all
conditions, including a light load condition. These
systems, moreover, can be achieved without an input
electrolytic capacitor.
The IC employs the average current and quasi-resonant
controls: the average current control realizes high power
factors, whereas the quasi-resonant control contributes to
high efficiency and low noise.
Having a rich set of protection features, the IC can
provide and more cost-effective power supply systems
with fewer external components.

Features
● Built-in On-time Control Circuit
(High Power Factor Achieved by Average Current
Control)
● Built-in Startup Circuit
(Reduced Numnber of External Components)
● Soft Start Function
(Startup Stress Reduction for Power MOSFET and
Secondary Rectifier Diode)
● Bias Assist Function
(Improved Startup Performance, VCC Voltage Drop
Suppresion in Operation, Reduced Capacitance of
VCC Pin Capacitor)
● Leading Edge Blanking Function
● Built-in Maximum On-time Limitation Function
● Protections Include:
Overcurrent Protection (OCP): Pulse-by-Pulse
VCC Pin Overvoltage Protection (VCC_OVP)
OCP Pin Overvoltage Protection (OCP_OVP)
OVP Pin Overvoltage Protection (OVP_OVP)
Overload Protection (OLP)
Thermal Shutdown (TSD)

Applications
● LED Lighting Equipment
● LED Bulbs