Research And Design Of White LED Driver

LED (Light Emitting Diode) is a new type semiconductor solid-state light sources, which has many advantages, such as energy saving and long life etc. Therefore, as the growing tension in the global energy and increasing bressure in environmental protection, using the semiconductor lighting of LED is the best way. With the development of semiconductor technology, the application of white LED is more extensive. To meet various lighting applications of different input voltage and output current, various typier of LED drivers have been designed. Therefore,the demand of white LED is huge, the research of the LED driver is fashion.By the research of white LED drive of which type is the DC/DC (direct current/direct current) switch power, the subject analysis the drive type, the drive mode of switch tube, feedback control pattern, process contrast and power consumption of PWM switch mode which contains oscillation circuit. To reduce power consumption of swich tube which contains oscillation and EMI (Electromagnetic Interference), the application of no oscillator and current feedback control are designed for white LED driver by the purpose of stable, efficient and low-cost.The Boost structure is used to realize white LED drive in this paper, the drive circuit is constituted of four parts which are bandgap reference voltage, comparer1, comparer2 and stationary trigger, explain those fuction and overall principle with the application Compared start structure is designed for bandgap reference voltage, which resolve the quesiton of simple and parallel. Based on the bipolar process, four parts of white LED are designed, simulation annlysis and principle explain is gived by the tool of Spectre of Cadence. Overall simulation validation states that the circuit gets balance in 1.2us with 5V voltage; the circuit can maintain stable in 2.5-5V input voltage, which can achieve the purpose of driving white LED.Finally, the territory of the LED drive circuit is designed based on bipolar process, and painted by applicating Cadence. The territory is validated for DRC and LVS by the tool of Dracular, which is a territory validate tool of Cadence.