Title :
A Novel Control Technique for Single-Inductor Multiple-Output DC-DC Buck Converters
Author :
Patra, Pradipta ; Samanta, Susovon ; Patra, Amit ; Chattopadhyay, Souvik
Author_Institution :
IIT Kharagpur, Kharagpur
Abstract :
This paper presents the design of a single-inductor regulated multiple-output (SIMO) buck converter with interleaved switched capacitor outputs. A small signal analysis of the buck converter using state space averaging technique is carried out. A compensating network and novel control logic are designed to minimize effects of cross regulation and load transient in the three-coupled outputs. In view of the significant advantages of current-mode control over voltage-mode the main switch of this multiple-output converter is made current-controlled. Interestingly, sub-harmonic oscillations start occurring at a much lower duty cycle than 0.5 in multiple-output current controlled converters. Our work focuses on the cause of instability and the minimum duty ratio beyond which sub-harmonic oscillations occur. Lastly, the expression of a slope-compensating ramp, required to eliminate sub-harmonic oscillations, has been derived for multiple-output converters. The transistor level design of the above has been designed and simulated in cadence analog environment in a 0.5 mu process. The simulation results are in conformity with the evaluated stabilizing ramp to eliminate sub-harmonic oscillations.
Keywords :
DC-DC power convertors; compensation; electric current control; harmonic oscillators; power inductors; switched capacitor networks; voltage control; compensating network; control logic; current-mode control; interleaved switched capacitor; signal analysis; single-inductor multiple-output dc-dc buck converter; state space averaging; subharmonic oscillation; voltage-mode control; Buck converters; Circuit simulation; DSL; Inductors; Open loop systems; Signal analysis; State-space methods; Switches; Transfer functions; Voltage control;
Conference_Titel :
Industrial Technology, 2006. ICIT 2006. IEEE International Conference on
Conference_Location :
Mumbai
Print_ISBN :
1-4244-0726-5
Electronic_ISBN :
1-4244-0726-5
DOI :
10.1109/ICIT.2006.372361