The low-power and low-area PWM by light intensity for photoflash in 0.35-μm CMOS

Abstract

The pulse width modulator by light intensity is presented. Light intensity sensing is achieved by using capacitor, photodiode, and comparator. And IGBT driver has short circuit protection using delay cell. The pulse width modulator has the operating range of V MS from 0.5V to 2.9V. The pulse width modulator fabricated in 0.35-µm CMOS technology occupies 0.85mm x 0.56mm. This circuit consumes 1.2mA at 300Hz and 3.0V.