Design of a high efficiency boost DC-DC converter

Abstract

Abstract：An accurate circuit of PWM/PFM mode converting and a circuit of auto-adaptively adjusting dimension of power transistor are described. The duty cycle of the signal when the control mode converts can be gained accurately by using ratios of currents and capacitances, and an optimal dimension of power transistor is derived with different loads. The converter is designed by 0.35 μm standard CMOS technology. Simulation results indicate that the converter starts work at 0.8 V input voltage. Combined with synchronized rectification, the transfer efficiency is higher than 90% with full load range, and achieves 97.5% at rating output. Keywords：control mode；power transistor；synchronized rectification；efficiency With the development of portable electronics, the high efficiency DC-DC converter is becoming a hot research subject [1][2][3] . The longevity of the battery is primarily determined by the power consumption and the transfer efficiency of the converter. Traditional pulse width modulation (PWM) DC-DC converter provides high stability and low output ripple with constant frequency, but the transfer efficiency reduces obviously with light load. Pulse frequency modulation (PFM) DC-DC converter provides high transfer efficiency with light load or even standby state with variable frequency, but the noise and electro magnetic interference (EMI) in converter is hard to filter [4,5] . An accurate circuit of PWM/PFM mode converting and a circuit of auto-adaptively adjusting dimension of power transistors are described in this paper. The converter works in PWM mode with heavy load while in PFM mode with light load, and this converter auto-adaptively adjusts the dimension of power transistor by estimating the load condition. Combined with synchronized rectification, the converter achieves high transfer efficiency during large load range.

Style classification and prediction of residential buildings based on machine learning

“…For example, both minimalism and modernism use simple rectangular forms, and both Baroque and Rococo use complex curves (Claudia and Daniela 2019). Second, architectural historians have proposed different theoretical and philosophical views, such as constructivism (Frampton and Cava2001), deconstructivism (Xue 2019) and functionalism (Gao 2009). There is no uniform standard.…”