Title :
PWM switch model of a buck-boost converter operated under discontinuous conduction mode
Author :
Reatti, Alberto ; Balzani, Marianna
Author_Institution :
Dept. of Electron. & Telecommun., Florence Univ.
Abstract :
A small-signal circuit model for PWM dc-dc converters operated in discontinuous conduction mode DCM is presented. The model is composed of controlled current sources, and resistances. The principle of energy conservation approach is utilized to take into account parasitic resistances of the transistor and diode and the diode threshold voltage. The proposed model is suitable for small-signal, frequency-domain representation of the converters. This model is used to derive the expressions for a buck-boost converter control-to-output transfer function, input-to-output voltage transfer function, input impedance, and the output impedance. Bode plots are also given for these transfer functions
Keywords :
Bode diagrams; DC-DC power convertors; PWM power convertors; frequency-domain analysis; switching convertors; transfer functions; Bode plots; PWM dc-dc converters; PWM switch model; RHP zero; buck-boost converter; controlled current sources; diode parasitic resistances; diode threshold voltage; discontinuous conduction mode; energy conservation; frequency-domain representation; input impedance; output impedance; small-signal circuit model; transfer functions; transistor parasitic resistances; Circuits; DC-DC power converters; Diodes; Energy conservation; Impedance; Pulse width modulation; Pulse width modulation converters; Switches; Switching converters; Transfer functions;
Conference_Titel :
Circuits and Systems, 2005. 48th Midwest Symposium on
Conference_Location :
Covington, KY
Print_ISBN :
0-7803-9197-7
DOI :
10.1109/MWSCAS.2005.1594189
