Research And Design Of A Multi-channel Boost LED Driver Chip

LED(Light Emitting Diode) is a new generation of light resource, known as "green light", which is characterized as high efficiency, energy-saving, environment-friend, long life and high reliability. LED is gradually replacing traditional lighting. Because of its electrical properties, LED requires a specific drive circuit.This paper describes the principle of white LED light, the luminescence properties and the I-V characteristics; the principle and development of power management chip. We analyze the topology structure of four kinds of DC-DC switching power supply: buck, boost, buck-boost, Cuk, three kinds of modulation:PWM, PFM, PSM. and two kinds of feedback control:Voltage feedback mode and Current feedback mode. In this paper, the PWM modulation, the peak current feedback control mode, the inductor current continuous mode is adopted. This paper describes the design of multi-channel boost DC-DC LED driver IC’s system structure, working principle, circuit structure and simulation results of the main internal modules of the chip. We focus on analyzing the principle of multi-channel LED driver and design a multi-channel LED driver which can realize driving 1-10 channels LED simultaneously, which each channel has 1-10 LEDs. We also discuss a new type of thermal shutdown current. The chip also has over current protection circuit, which can improve protection to circuit and reliability of chips by a current more sensitive to temperature. The current is calculated by subtracting positive and negative temperature coefficient current.The chip use HHNEC_BCD 350 process. It has wide input voltage range:8V-30V, high output voltage:40V, max load current:1A, efficiency:83.4%, current matching accuracy of each LEDs:2.04%or less. The simulation results using Cadence software show that the function and the performance of the chip have met the design requirements.