A 64-Gb/s 4-PAM Transceiver Utilizing an Adaptive Threshold ADC in 16-nm FinFET
A 64-Gb/s 4-PAM Transceiver Utilizing an Adaptive Threshold ADC in 16-nm FinFET
复制标题
采用 16 nm FinFET 的自适应阈值 ADC 的 64 Gb/s 4-PAM 收发器
DOI：
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发表时间：
2019
影响因子：
5.4
通讯作者：
A. Chan Carusone
中科院分区：
文献类型：
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作者：
Luke Wang;Yingying Fu;Marc;Euhan Chong;A. Chan Carusone
提出了一种采用16 nm鳍式场效应晶体管（FinFET）技术制造的64 Gb/s 4脉冲幅度调制（PAM）收发器，其功耗与链路损耗成比例。发射机（TX）包括一个三抽头前馈均衡器（FFE）（一个前置，一个后置），可实现99%的电平分离失配比（RLM）和162 fs rms的随机抖动（RJ）。最大摆幅为1.1 Vppd，功耗为89.7 mW，包括来自1.2 V电源的时钟分配，对应于1.39 pJ/bit。接收机模拟前端（RX-AFE）由半速率（HR）采样连续时间线性均衡器（CTLE）和能够进行非均匀量化的6位闪存（1位折叠）模数转换器（ADC）组成。基于贪婪搜索方法来选择非均匀阈值，该贪婪搜索方法允许RX以高粒度的方式在低信道损耗下降低功率，并且实现比均匀量化器更好的误比特率（BER）。对于奈奎斯特时具有−8.6 dB损耗的通道，ADC可以配置为2位模式，在RX-AFE功耗为100 mW时实现BER <1 e- 6。对于−29.5 dB损耗信道，RX-AFE功耗为283.9 mW，结合软件数字均衡器可实现BER <1 e- 4。对于−13.5 dB损耗信道，使用贪婪搜索来优化量化阈值水平，与均匀量化相比，BER提高了一个数量级。
A 64-Gb/s 4-pulse-amplitude modulation (PAM) transceiver fabricated with a 16-nm fin field effect transistor (FinFET) technology is presented with a power consumption that scales with link loss. The transmitter (TX) includes a three-tap feed-forward equalizer (FFE) (one pre and one post) achieving a level separation mismatch ratio (RLM) of 99% and a random jitter (RJ) of 162-fs rms. The maximum swing is 1.1 Vppd at a power consumption of 89.7 mW including clock distribution from a 1.2-V supply, corresponding to 1.39 pJ/bit. The receiver analog front end (RX-AFE) consists of a half-rate (HR) sampling continuous-time linear equalizer (CTLE) and 6-bit flash (1-bit folding) analog-to-digital converter (ADC) capable of non-uniform quantization. The non-uniform thresholds are selected based on a greedy search approach which allows the RX to reduce power at low channel loss in a highly granular manner and achieves better bit error rate (BER) than a uniform quantizer. For a channel with −8.6-dB loss at Nyquist, ADC can be configured in 2-bit mode, achieving BER < 1e – 6 at an RX-AFE power consumption of 100 mW. For a −29.5-dB loss channel, the RX-AFE consumes 283.9 mW and achieves a BER < 1e – 4 in conjunction with a software digital equalizer. For a −13.5-dB loss channel, a greedy search is used to optimize the quantization threshold levels, achieving an order of magnitude improvement in BER compared to uniform quantization.