A Two-Tone Test Method for Continuous-Time Adaptive Equalizers
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With the increasing demand of higher bandwidth, the data rate of I/Os is approaching the tens of gigahertz range. While the continuing advancement of process technology enables an I/O chip to run at such frequencies, the bandwidth of the communication channels, including cables and legacy backplanes, has become the limiting factor.
The bandwidth limitation of the channel causes ISI. Various equalization techniques, which multiply the inverse response of the channel to flatten out the overall frequency response, have been developed to compensate for this channel effect. In addition, the channel characteristics may not be known in advance and might be time-variant . To cope with such problems, several adaptation algorithms have also been developed to adjust the overall system response depending on the channel conditions.
The equalizer can be implemented either in the transmitter or in the receiver. The implementation of the transmitter equalizer is relatively easier than that of the receiver equalizer because the required Finite Impulse Response (FIR) filter deals with the digital data at the transmitter side, rather than the received analog data at the receiver side [60, 61]. However, since channel information is not easily available at the transmitter, it is difficult to apply the adaptive technique at the transmitter.
KeywordsReceive Analog Data Filter Deals Gigahertz Range Equalization Filter Adaptive Loop
- 9.Robertson I et al. (Nov 2005) Testing high-speed, large scale implementation of SerDes I/Os on chips used in throughput computing systems. In: Proceedings of International Test Conference, pp 1–8Google Scholar
- 59.Zerbe J (2005) Comparison of adaptive and non-adaptive equalization methods in high-performance backplanes DesignConGoogle Scholar
- 60.Liu J, Lin X (2004) Equalization in high-speed communication systems. IEEE Circuits Systems Magazine, Second quarter, pp 4–17Google Scholar
- 64.Sun R et al. (Sept 2005) A low-power, 20-Gb/s continuous-time adaptive passive equalizer. In: Proceedings of International Symposium on Circuits and Systems, pp 920–923Google Scholar
- 66.Ahang G et al. (Feb 2004) A BiCMOS 10 Gb/s Adaptive cable equalizer. In: Proceedings of International Solid-State Circuits Conference, pp 92–93Google Scholar
- 67.Maxim Integrated Products (2003) Designing a simple, wide-band and low-power equalizer for FR4 copper link, DesignConGoogle Scholar
- 68.Lee J (Feb 2006) A 20-Gb/s adaptive equalizer in 0.13 um CMOS technology. In: Proceedings of International Solid-State Circuits Conference, pp 92–93Google Scholar
- 69.Sun R et al. (June 2006) A tunable passive filter for low-power high-speed equalizers. In: Proceedings of VLSI Circuit Symposium, pp 198–201Google Scholar
- 71.Tripp M et al. (Oct 2003) Elimination of traditional functional testing of interface timings at Intel. In: Proceedings of International Test Conference, pp 1014–1022Google Scholar
- 72.Sun R (Dec 2005) A low-power, 20-Gb/s continuous-time adaptive passive equalizer, MS thesis, Carnegie Mellon UniversityGoogle Scholar