一种光接收机中的高增益宽动态范围跨阻放大器

As the front-end preamplifiers in optical receivers, transimpedance amplifiers （TIAs） are commonly required to have a high gain and low input noise to amplify the weak and susceptible input signal. At the same time, the TIAs should possess a wide dynamic range （DR） to prevent the circuit from becoming saturated by high input currents. Based on the above, this paper presents a CMOS transimpedance amplifier with high gain and a wide DR for 2.5 Gbit/s communications. The TIA proposed consists of a three-stage cascade pull push inverter, an automatic gain control circuit, and a shunt transistor controlled by the resistive divider. The inductive-series peaking technique is used to further extend the bandwidth. The TIA proposed displays a maximum transimpedance gain of 88.3 dBΩ with the -3 dB bandwidth of 1.8 GHz, exhibits an input current dynamic range from 100 nA to 10 mA. The output voltage noise is less than 48.23 nV/√Hz within the -3 dB bandwidth. The circuit is fabricated using an SMIC 0.18 μm 1P6M RFCMOS process and dissipates a dc power of 9.4 mW with 1.8 V supply voltage.     

A 10-bit 100-MS/s CMOS pipelined folding A/D converter

This paper presents a 10-bit 100-MSample/s analog-to-digital（A/D） converter with pipelined folding architecture.The linearity is improved by using an offset cancellation technique and a resistive averaging interpolation network.Cascading alleviates the wide bandwidth requirement of the folding amplifier and distributed interstage track/hold amplifiers are used to realize the pipeline technique for obtaining high resolution.In SMIC 0.18μm CMOS,the A/D converter is measured as follows:the peak integral nonlinearity and differential nonlinearity are±0.48 LSB and±0.33 LSB,respectively.Input range is 1.0 V_P-P with a 2.29 mm² active area.At 20 MHz input @ 100 MHz sample clock,9.59 effective number of bits,59.5 dB of the signal-to-noise-and-distortion ratio and 82.49 dB of the spurious-free dynamic range are achieved.The dissipation power is only 95 mW with a 1.8 V power supply.     

用于片上网络的全异步串行连接转换器

针对传统片上网络路由器之间互连线过多,传输功耗大的缺陷,提出了一种用于全异步片上网络的串行传输转换器。通过将路由器之间的并行数据分组并以更小的数据块传输,使得片上路由之间的互连线成倍减少,并可以大大减小传输过程带来的功率损耗。零协议逻辑门限门的应用使电路准延时不敏感,提高了转换器的鲁棒性。基于SMIC 0.18μm标准CMOS工艺实现了此串行连接转换器及串行通道。结果表明,在32位数据位宽下,此全异步串行连接转换器可节约路由器之间近3/4的连线资源以及减少近2/3的功耗。此全异步串行连接转换器适用于对面积和功耗较为敏感的片上网络互连应用。     

基于90nm CMOS工艺的一种10位低功耗SAR A/D转换器

Traditional and some recently reported low power,high speed and high resolution approaches for SAR A/D converters are discussed.Based on SMIC 65 nm CMOS technology,two typical low power methods reported in previous works are validated by circuit design and simulation.Design challenges and considerations for high speed SAR A/D converters are presented.Moreover,an R–C combination based method is also addressed and a 10-bit SAR A/D converter with this approach is implemented in SMIC 90 nm CMOS process.The DNL and INL are measured to be less than 0.31 LSB and 0.59 LSB respectively.With an input frequency of 420 kHz at 1 MS/s sampling rate, the SFDR and ENOB are measured to be 67.6 dB and 9.46 bits respectively,and the power dissipation is measured to be just 3.17 mW.     

一种65nm CMOS互连线串扰分布式RLC解析模型

基于65nm CMOS工艺,综合考虑电容耦合与电感耦合效应,提出了一种互连线耦合串扰分布式RLC解析模型.采用函数逼近理论与降阶技术,在斜阶跃输入信号下,提出了被干扰线远端的串扰数值表达式.基于65nm CMOS工艺,对不同的互连耦合尺寸下的分布式RLC串扰解析模型和Hspice仿真结果进行了比较,误差绝对值都在2.50%内,能应用于纳米级SOC的计算机辅助设计.     

硅基毫米波高增益LNA技术研究

针对W波段硅基工艺电路面临的功率增益低、效率低以及噪声差等挑战,本文研究硅基毫米波高增益低噪声放大器（Low Noise Amplifier,LNA）技术。该LNA采用带有射极电感反馈的共射放大器,并通过五级共射放大器级联构成。第一级电路通过提供最小噪声偏置电流,并利用最小噪声匹配实现低噪声性能,后级电路通过提供高增益偏置电流实现高增益性能。另外,为了减小射频信号到衬底的损耗以及信号与旁路元件的耦合,有效提高低噪声放大器的性能,用于匹配电路的电感全部采用传输线形式—接地共面波导。低噪声放大器在中心频率94 GHz处的增益S21达到25.2 dB,噪声系数NF小至5.1dB。在90～100 GHz频段内,输入反射系数S11小于-10 dB,输出反射系数S22稳定在-20 dB左右,芯片面积为500 μm×960 μm。     

CMOS多晶电容工艺误差分析及设计研究

研究分析了CMOS多晶电容的工艺误差,给出了氧化硅介质层厚度的梯度误差、边际效应等工艺因素对CMOS多晶电容的影响。基于单位电容的改进设计,给出了CMOS多晶电容阵列的共心设计方法。采用0．6μm CMOS DPDM工艺,实现了基于CMOS多晶电容阵列的开关电容带通滤波器,实验结果表明本文的CMOS多晶电容设计方法具有较高的精度,能直接用于亚微米及深亚微米集成电路设计。     

8位 80 MS/s低功耗流水线型ADC的设计

采用每级为1.5位或者2位精度的7级流水线结构,即7级子ADC,设计了一款8位80 MS/s的低功耗模数转换电路。利用每一级子ADC中的钟控开关及电容实现采样保持功能,节省了整个ADC的采样保持电路模块。在满足整个ADC性能情况下,采用了逐级缩放技术,减小了芯片面积和功耗。版图设计中,考虑了每一级ADC中电容及放大器的对称性,减小了电容失配对整个ADC性能的影响。采用0.18 μm CMOS工艺,在输入信号为11.25 MHz,采样速率为80 MHz的条件下,信噪比(SNR)为49.5 dB,有效位数(ENOB)为7.98 bits,整个ADC的芯片面积为0.56 mm²,典型工作电流为22 mA。     

一种基于前馈补偿技术的高性能CMOS运算放大器

基于传统CMOS折叠共源共栅运算放大器的分析和总结,应用前馈补偿技术,实现了一种高性能CMOS折叠共源共栅运算放大器,不仅保证了高开环增益,而且还大大减小了运放的输入失调电压。设计采用TSMC 0.35μm混合信号CMOS工艺实现,采用Hspice进行仿真,仿真结果表明运放的直流开环增益为95 dB,输入失调电压为0.023 mV,负载电容为2pF时的相位裕度为45.5°。     

A low overhead load balancing router for network-on-chip

The design of a router in a network-on-chip (NoC) system has an important impact on some performance criteria. In this paper, we propose a low overhead load balancing router (LOLBR) for 2D mesh NoC to enhance routing performance criteria with low hardware overhead. The proposed LOLBR employs a balance toggle identifier to control the initial routing direction of X or Y for flit injection. The simplified demultiplexers and multiplexers are used to handle output ports allocation and contention, which provide a guarantee of deadlock avoidance. Simulation results show that the proposed LOLBR yields an improvement of routing performance over the reported routing schemes in average packet latency by 26.5%. The layout area and power consumption of the network compared with the reported routing schemes are 15.3% and 11.6% less respectively.