General Description
The LD7838H is a 700V HV start-up flyback PFC controller,
specially designed for LED lighting. This device operates in
transition mode(TM) and integrates with completed
protections required. It minimizes the components counts
in either SOP-7 package. Those make it easy to design
with for cost-effective applications.
With HV start-up technology, high power factor and TM
control, the start-up time and resistor loss could be
minimized efficiently. The circuit can easily achieve
PF>0.90 to meet most of the international standard
requirements.
With completed protection built inside this IC, such as
over voltage protection (OVP), over current protection
(OCP), over load protection (OLP), over temperature
protection (OTP), and output short circuit protection
(OSCP), It enable the circuit to meet most safety
requirements in both normal and abnormal test.

Features
 High voltage (700V) startup circuit for 305VAC
 High Power Factor Flyback PFC controller
 High-efficiency Transition mode operation
 Low Operation Current and Fast start up
 Accurate OLP Compensation for High/ Low Line
 BNI/ BNO Detection Function by HV pin
 Wide UVLO (16.5 Von and 8 Voff) Range
 Cycle by Cycle Current Limiting for Over Current
Protection
 OVP (Over Voltage Protection) Function by ZCD
and VCC pin
 Internal OTP function

Applications
 LED Power Supply
 LED Light Bulb/Tube