Improved light-load efficiency for synchronous rectifier voltageregulator module

摘要

DC/DC converter with high efficiency over a wide load range isnnecessary for many low voltage applications, such as battery suppliednsystems and micro-processor power supplies-voltage regulator modulen(VRM). In order to improve the efficiency of low voltage converters,nsynchronous rectifier technology is widely used. The disadvantage ofnthis technology is low efficiency at light load. This paper proposes annew technology, which utilizes the duty cycle signal, to improve lightnload efficiency with simple implementation. Since current sensors arennot required, high density and high efficiency can be achieved thatnmakes the whole circuit suitable for integration. In the paper, twonapplication examples are given. Experimental results verified that thenproposed control schemes significantly improve the efficiency ofnsynchronous rectifier buck converters at light load