Light emitting diodes (LEDs) are current driven devices. So, it is essential to maintain the stability of LED voltage and current. Variation temperature may cause instabilities bifurcations in driver. Driving LEDs from an offline power source faces design challenges like have low harmonics input current, achieve high factor, efficiency constant ensure long lifetime. This paper proposes techniqu...

A flicker-free resonant LED driver with high power factor (PF) and passive current balancing is proposed analysed in this paper. The are composed a buck correction (PFC) unit dc-dc by sharing an active switch. Based on topology, the low output ripple can be achieved via small voltage bulk capacitor fast voltage-mode control loop. By charge balance for capacitor, of each string balanced. In half...

PSPICE modeling of a commercial LED driver IC (TOP245P) and PC817A optocoupler is proposed for the switch-mode power supply (SMPS) (applicable to LED driver) design and simulation. An analog behavioral model of the TOP245P IC including the shunt regulator, undervoltage(UV) detection, over-voltage(OV) shut-down and SR flip-flop is developed by using PSPICE. The empirical equation of PC817A curre...

Abstract – Modeling of the cascode switching structure used in Flyback converter for achieving fast startup in the deeply dimmed phase-cut LED driver is presented in this paper. The cascode structure’s inherent instability and oscillation issue is modeled and analyzed quantitatively. Three solutions are proposed to stabilize the structure and suppress the unstable voltage oscillation. Solutions...

The NCL30001 is a highly integrated controller for implementing power factor correction (PFC) and isolated step down ac−dc power conversion in a single stage, resulting in a lower cost and reduced part count solution. This controller is ideal for LED Driver power supplies with power requirements between 40 W and 150 W. The single stage is based on the flyback converter and it is designed to ope...

High power Light Emitting Diodes (HPLEDS) are adopted for lighting purpose, making them the fastest growing light source worldwide. This paper discusses HPLED lamp of various shapes with different lux levels and different heat sink requirements when used for indoor lighting. To provide constant current to LED, a driver circuit is designed using a dc to dc converter and a microcontroller. The in...