A 4-channel 10.3Gb/s backplane transceiver macro with 35dB equalizer and sign-based zero-forcing adaptive control
A 4-channel 10.3Gb/s backplane transceiver macro with 35dB equalizer and sign-based zero-forcing adaptive control
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DOI：
10.1109/isscc.2009.4977371
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
Y. Hidaka;Weixin Gai;T. Horie;J. Jiang;Y. Koyanagi;H. Osone
中科院分区：
文献类型：
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作者：
Y. Hidaka;Weixin Gai;T. Horie;J. Jiang;Y. Koyanagi;H. Osone
背板上电信号的最大波特率受到连接器处的反射和串扰噪声以及由频率相关介电损耗引起的ISI的限制。DFE是在不放大噪声的情况下减轻ISI的有效电路。通常使用多抽头DFE来消除长尾ISI [1-3]。然而，当使用非推测抽头[1，2]时，由于模拟反馈，多个DFE抽头可能限制最大操作速度，或者当使用多个推测抽头[3]时，以指数方式增加功率和面积。另一种方法是将1抽头推测DFE与线性均衡器（LE）相结合，以获得更快的速度，消除长尾ISI [4，5]。当组合LE和DFE时，自适应控制具有挑战性，因为必须考虑LE和DFE之间的关系[5]，并且DFE中常用的符号-符号-最小均方（SS-LMS）算法[7]不适用于某些类型的LE，或者以LE中并行信号路径的功率和面积增加为代价[6]。模拟滤波器的迫零（ZF）算法[8]适用于任何类型的LE，但它需要ADC和大量逻辑来执行矩阵乘法。启发式算法[5]需要眼睛测量电路、微控制器和控制软件。
Maximum baud rate of electrical signaling over backplanes is limited by reflection and crosstalk noise at connectors as well as ISI caused by frequency-dependent dielectric loss. A DFE is an effective circuit to alleviate ISI without amplifying noise. A multi-tap DFE is often used in order to cancel long-tail ISI [1–3]. However, multiple DFE taps may limit maximum operation speed due to analog feedback when using non-speculative taps [1,2], or increase power and area exponentially when using multiple speculative taps [3]. Another approach is a combination of a 1-tap speculative DFE to get faster speed and a linear equalizer (LE) to cancel the long-tail ISI [4,5]. Adaptive control is challenging when combining LE and DFE, because the relationship between LE and DFE must be taken into account [5], and the sign-sign-least-mean-square (SS-LMS) algorithm [7] that is commonly used in DFEs is not applicable to some types of LE, or at the cost of increased power and area for parallel signal paths in LE [6]. The zero-forcing (ZF) algorithm for analog filters [8] is applicable to any type of LE, but it needs an ADC and a large amount of logic to perform matrix multiplication. A heuristic algorithm [5] requires an eye measurement circuit, microcontroller, and control software.