The BP3122 is a high precision primary-side feedback and regulation controller for LED lighting that functions in constant current control mode and is designed to work in inductor current discontinuous conduction mode, making it particularly ideal for fly back converters with universal input. The system's output power should be less than 5W. The BP3122 contains a 650V power MOSFET. The secondary sensing and feedback circuit has been deleted since the adoption of main sense and feedback control technology. The looping compensatory components are likewise deleted while the overall operating conditions remain stable. It employs patent-pending source driver design and demagnetization detecting technology, has a very low operating current, and does not require an extra winding for measuring output current and powering the device. Because of the low component counts Using the innovative high precise current sensing technology, the BP3122 achieves 5% LED current accuracy as well as good line and load control. The BP3122 includes several protective features such as LED open/short circuit protection, CS resistor short circuit protection, over-temperature protection, and VCC under voltage protection.