A current-mode PWM control CMOS power converter with novel slope compensation circuits for biomedical applications

A lower power consumption, smaller output ripple and better regulation current-mode CMOS buck power converter with a novel on-chip slope compensation circuits for feedback control is presented in this paper. In current-mode converters, the slope compensation circuits needs to add ramp voltage signal with the inductor current signal in order to avoid subharmonic oscillation. The converter is designed and simulated using the TSMC 0.18um CMOS Process. Hspice simulation results show that, the buck converter having 1.129×1.200mm² chip size with power efficiency about 90%. This chip can operate with input supply voltage from 2.8V to 3.3V, and its output voltage can stable at 1.2V and less than 22mV ripple voltage at maximum loading current 500mA for biomedical or low power applications.