A High-Swing 45 Gb/s Hybrid Voltage and Current-Mode PAM-4 Transmitter in 28 nm CMOS FDSOI
A High-Swing 45 Gb/s Hybrid Voltage and Current-Mode PAM-4 Transmitter in 28 nm CMOS FDSOI
复制标题
采用 28 nm CMOS FDSOI 的高摆幅 45 Gb/s 混合电压和电流模式 PAM-4 发送器
DOI：
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发表时间：
2016
影响因子：
5.4
通讯作者：
A. Mazzanti
中科院分区：
文献类型：
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作者：
M. Bassi;F. Radice;M. Bruccoleri;S. Erba;A. Mazzanti
在日益增长的高速连接需求的推动下，下一代400 Gb/S电力链路正瞄准PAM-4调制，以限制信道损耗和节省链路预算。与NRZ相比，更高的幅度是可取的，以抵消PAM-4垂直开眼量减少1/3的影响。然而，线性度也是关键，PAM-4级别必须精确间隔，以保持其相对于NRZ的水平睁眼优势。本文介绍了一种45 Gb/S PAM-4发射机，它能够提供非常大的输出摆幅，并具有增强的线性度和最新的效率。该驱动器围绕电流模式和电压模式拓扑的混合组合构建，嵌入4抽头5位前馈均衡器(FFE)，并允许调节输出阻抗，以确保良好的源端接。全发射器采用28 nm CMOSFDSOI工艺实现，包括一个半速率串行器、占空比校正电路、>；>；2 kV HBM ESD二极管，在45 Gb/S速率下提供1.3Vppd的全摆幅，而1 V电源仅消耗120 mA。功率效率比以前报道的PAM-4发射机高出约2倍。
Pushed by the ever-increasing demand of high-speed connectivity, next generation 400 Gb/s electrical links are targeting PAM-4 modulation to limit channel loss and preserve link budget. Compared to NRZ, a higher amplitude is desirable to counteract the 1/3 reduction of PAM-4 vertical eye opening. However, linearity is also key, and PAM-4 levels must be precisely spaced to preserve the horizontal eye opening advantage it has over NRZ. This paper presents a 45 Gb/s PAM-4 transmitter able to deliver a very large output swing with enhanced linearity and state-of-the-art efficiency. Built around a hybrid combination of current-mode and voltage-mode topologies, the driver is embedded into a 4-taps 5-bits feed-forward equalizer (FFE), and allows tuning the output impedance to ensure good source termination. Implemented in 28 nm CMOS FDSOI process, the full transmitter includes a half-rate serializer, duty-cycle correction circuit, >> 2 kV HBM ESD diodes, and delivers a full swing of 1.3 Vppd at 45 Gb/s, while drawing only 120 mA from 1 V supply. The power efficiency is ~ 2 times better than previously reported PAM-4 transmitters.