An Exact Current-Mode PFM Boost Converter With Dynamic Stored Energy Technique

A novel pulse frequency modulation step-up dc-dc converter with maximum power conversion of 91.91% and steady-state accuracy of 0.33% is presented in this letter. The high efficiency and exact output are achieved by a dynamic stored energy technique that enhances utility rate of energy with less power consumption. This technique uses a dynamic sensing current controller and a load current detector that accurately generates different energy according to various load conditions. The boost converter has been designed and fabricated with a standard TSMC 3.3/5 V 0.35- mum 2P4M CMOS technology. Experimental results show that the output up-ripple voltage variation was 2.5 mV (6.1-8.6 mV), whereas its fixed energy counterpart was 39.4 mV (8.6-48 mV). The proposed boost converter has 16% higher power conversion efficiency than the conventional fixed energy technique at 1 mA load current.