A Novel Dual-Function Circuit Combining High-Speed Differential Equalizer and Common-Mode Filter With an Additional Zero

Author

Chih-Ying Hsiao ; Tzong-Lin Wu

Author_Institution

Dept. of Electr. Eng., Nat. Taiwan Univ., Taipei, Taiwan

Volume

24

Issue

9

fYear

2014

fDate

Sept. 2014

Firstpage

617

Lastpage

619

Abstract

A new circuit topology combining differential-mode equalizer and common-mode filter is proposed to apply in high-speed digital channel. A differential shunt stub (DSS), which is required in passive equalizer in improving the eye pattern quality, provides an additional transmission zero for the common-mode band-stop filter. This additional zero can be tuned dynamically by adjusting the DSS length and thus enhance the stop-band depth and bandwidth. This topology is implemented on a three-layer PCB. The eye opening is significantly improved for 8 Gb/s differential signals. In addition, the common-mode fractional bandwidth is enhanced from 13% to 46% by introducing an additional zero. Good agreement between simulation and measurement will be seen.

Keywords

band-stop filters; equalisers; DSS length; bit rate 8 Gbit/s; common-mode band-stop filter; differential shunt stub; differential signals; differential-mode equalizer; dual-function circuit; eye pattern quality; fractional bandwidth; high-speed digital channel; passive equalizer; stop-band bandwidth; stop-band depth; three-layer PCB; transmission zero; Bandwidth; Decision support systems; Equalizers; Filtering theory; Integrated circuit modeling; Resistors; Resonant frequency; Common-mode (CM) filter; electromagnetic interference (EMI); equalizer; high-speed differential signaling; inter-symbol interference (ISI);

fLanguage

English

Journal_Title

Microwave and Wireless Components Letters, IEEE

Publisher

ieee

ISSN

1531-1309

Type

jour

DOI

10.1109/LMWC.2014.2328896

Filename

6832622