A programmable integrated digital controller for switching converters with dual-band switching and complex pole-zero compensation

Author

Chui, Martin Yeung-Kei ; Ki, Wing-Hung ; Tsui, Chi-ying

Author_Institution

Dept. of Electr. & Electron. Eng., Hong Kong Univ. of Sci. & Technol., China

Volume

40

Issue

3

fYear

2005

fDate

3/1/2005 12:00:00 AM

Firstpage

772

Lastpage

780

Abstract

The design of a 0.6-μm CMOS programmable integrated digital PID controller for a buck converter is presented. Several novel features are implemented. These include: 1) a dual-band switching scheme for sampling the output voltage for better output resolution; 2) a dual-band switching PWM generator with a modified tapped delay line for area efficiency; 3) a VCO driving a counter to serve as an ADC; 4) a programmable PID compensator employing variable integration times for enhancing accuracy and stability; and 5) complex pole-zero cancellation in extending the bandwidth of the control loop. The converter is designed for variable output applications, and the fast digital loop achieves a tracking time of 50 μs for a 1-V step change of the reference voltage. The converter switches at 1 MHz and attains a maximum efficiency of 90% when delivering a load of 125 mW.

Keywords

CMOS digital integrated circuits; compensation; digital control; poles and zeros; programmable controllers; switching convertors; three-term control; 0.6 micron; 1 MHz; 125 mW; 50 mus; 90 percent; CMOS programmable controller; PID controller; PWM generator; analogue-digital converter; area efficiency; buck converter; complex pole-zero compensation; control loop; digital control; dual-band switching; fast digital loop; programmable PID compensator; programmable integrated digital controller; switching converters; tapped delay line; variable integration times; voltage controlled oscillator; Buck converters; Counting circuits; Delay lines; Digital control; Dual band; Pulse width modulation; Sampling methods; Switching converters; Three-term control; Voltage-controlled oscillators; Digital control; digital PID controller; switching converter;

fLanguage

English

Journal_Title

Solid-State Circuits, IEEE Journal of

Publisher

ieee

ISSN

0018-9200

Type

jour

DOI

10.1109/JSSC.2005.843626

Filename

1408098