Adaptive On-Time Control Circuits for Buck Converter with Quick Dynamic Response

Abstract

This dissertation presents and studies the adaptive on-time control circuits for buck converter with quick dynamic response The adaptive on-time control circuits for buck converter are widely used for the improvement of light-load efficiency because it can reduce switching loss at light load condition In recent years switching power supply requirement has the trend of fast transient response because it can improve load transient response to reduce output capacitance especially to central processing unit (CPU) and high current slew rate load applications The main contributions of the dissertation are the development and analysis of the quick dynamic response of the ripple-based constant frequency on-time control circuit with virtual inductor current ripple for buck converter the constant frequency on-time control circuit for buck converter and constant current ripple on-time control circuit with native adaptive voltage positioning (AVP) design for voltage regulators (VRs) The concept of operation uses the high frequency feedback control to filter VOUT at the load transient and change the on-time width dynamically It not only prevents VOUT from dropping significantly at the droop but also reduces the settling time at the load transient compared to the control without quick response Both experimental and simulation results confirm that the proposed adaptive on-time control circuits for buck converter with quick dynamic response can reduce the cost and size of the output capacitance and improve load transient response

Date of Award	2014 Dec 24
Original language	English
Supervisor	Jiann-Fuh Chen (Supervisor)