ESR Zero Estimation and Auto-compensation in Digitally Controlled Buck Converters

Author

Zhao, Zhenyu ; Ahsanuzzaman, S.M. ; Prodi, Aleksandar

Author_Institution

Toronto Design Centre, Exar Corp., Toronto, ON

fYear

2009

fDate

15-19 Feb. 2009

Firstpage

247

Lastpage

251

Abstract

A method for estimating and compensating the zero introduced by the capacitor equivalent series resistance (ESR) in the buck converter transfer function is introduced. The method is well-suited for practical implementation with digital controllers. The ESR zero is estimated by online measurement of the output voltage ripple and the power stage corner frequency. Accordingly, the coefficients of the PID compensator are updated to avoid potential stability problems. Theoretical basis of the identification and the compensator design are presented. The method is experimentally verified on a 12 V-to-1.5 V, 500 kHz, 10 W buck converter prototype.

Keywords

compensation; digital control; equivalent circuits; power capacitors; power convertors; three-term control; ESR zero estimation; PID compensator; autocompensation; buck converter transfer function; capacitor equivalent series resistance; digital controller; frequency 500 kHz; online measurement; power 10 W; Buck converters; Capacitors; Digital control; Electrical resistance measurement; Frequency estimation; Frequency measurement; Paramagnetic resonance; Power measurement; Transfer functions; Voltage;

fLanguage

English

Publisher

ieee

Conference_Titel

Applied Power Electronics Conference and Exposition, 2009. APEC 2009. Twenty-Fourth Annual IEEE

Conference_Location

Washington, DC

ISSN

1048-2334

Print_ISBN

978-1-4244-2811-3

Electronic_ISBN

1048-2334

Type

conf

DOI

10.1109/APEC.2009.4802663

Filename

4802663