LED drivers with PPD compensation for achieving fast transient response

Abstract

A trade-off performance between static error and dynamic response is made by the combination of proportional (P) and proportional derivative (PD) compensations. Owing to the fast transient response provided by the P compensator, the static error is also reduced by the PD compensator within a reasonable response time. The proposed control circuit is entirely implemented by voltage mode and has better line and load regulations. An asynchronous 1.8MHz DC/DC boost converter was fabricated by UMC 0-35 mu m to generate 35V output voltage to turn on more than 10 LED at the same time for the notebook's backlight.