High efficiency asynchronous PWM boost converter in 90nm CMOS technology for constant current LED driver

A PWM boost converter for constant current LED driver developed in TSMC 90nm 1P9M 3.3V CMOS technology process is presented in this paper. LED displays and LED backlighting systems are commonly used in portable devices, hence, this paper presents an implementation of a power management unit for constant current LED drivers. The application of the system is realized by having a three-channel constant current output which controls the luminance of LED's connected in series. The boost converter uses an asynchronous architecture setup and operates in voltage mode, thus, simplifies and had a smaller chip size implementation without compromising the efficiency in the implementation. The systems operating voltage is from 2.8 - 3.6V and can hold loads from 50mA - 200mA. The system provides efficiency as high as 94.4% at input voltage of 3.6V and a load of 100mA with a total chip size with pad dimension of 943.41μm × 568.14μm.