Gain-reconfigurable current-sensing circuit for high-frequency low-power dc-dc converters
Posted on:2011-05-12
Degree:M.Sc
Type:Thesis
University:University of Toronto (Canada)
Candidate:Yiu, C. Francis
Full Text:PDF
GTID:2442390002958763
Subject:Engineering
Abstract/Summary:
A novel current-sensing circuit that can operate from 1MHz to 4MHz has been designed and implemented for high-frequency low-power dc-dc power converter applications. The design is based on SenseFET concept with embedded SenseFETs in the main switch (MS) and synchronous rectifier (SR). An intermediate RC filter merges outputs from the MS and SR SenseFETs and supplies a smooth voltage signal to an op-amp. This reduces the need for a very high gain-bandwidth op-amp circuit and improves the efficiency of the power converter. The circuit has configurable feedback gain in order to increase current sensing accuracy when the average inductor current is small.