S6613SA is a high-precision primary-side feedback LED constant current control switching chip. It operates in discontinuous conduction mode of inductive current and is suitable for isolated flyback LED constant current power supplies with an input voltage range of 85~265Vac. S6613SA integrates a high-voltage power transistor internally and does not require auxiliary winding detection and power supply. The chip has a simple periphery and the system solution has high cost performance. The chip has built-in line voltage compensation and high-precision current sampling, and high current accuracy can be achieved without adding a current compensation circuit.