Research and design of a white LED driver chip applied in backlight

摘要

A white LED driver chip applied in backlight is proposed, which is based on pulse width modulator. The design of modules such as current reference, oscillator and dynamic slope compensation are discussed in detail. The simulation results, based on CSMC 0.5µm BCD technology, show that the input voltage is in the range of 3.3∼5.5V, the output voltage is up to 20V when the output current is between 15 ∼ 60mA, which can drive 2∼6 white LEDs in series with the conversion efficiency 88%. Characteristics such as the overall circuit loop stability, dynamic characteristics, load capacity are well satisfied the design requirements.