A novel one-dimensional(1D) analytical model is proposed for quantifying the breakdown voltage of a reduced surface field(RESURF) lateral power device fabricated on silicon on an insulator(SOI) substrate.We assume that the charges in the depletion region contribute to the lateral PN junctions along the diagonal of the area shared by the lateral and vertical depletion regions.Based on the assumption,the lateral PN junction behaves as a linearly graded junction,thus resulting in a reduced surface electric field and high breakdown voltage.Using the proposed model,the breakdown voltage as a function of device parameters is investigated and compared with the numerical simulation by the TCAD tools.The analytical results are shown to be in fair agreement with the numerical results.Finally,a new RESURF criterion is derived which offers a useful scheme to optimize the structure parameters.This simple 1D model provides a clear physical insight into the RESURF effect and a new explanation on the improvement in breakdown voltage in an SOI RESURF device.
In order to make a 10 Gbit/s 2:1 half-rate multiplexer operate without external clocks, a 5 Gbit/s clock recovery (CR) circuit is needed to extract the desired clock from one input data. For the CR circuit, a 3-stage ring voltage-controlled oscillator (VCO) is employed to avoid an unreliable startup of a 2-stage VCO and a low oscillation frequency of a 4-stage VCO. A phase frequency detector (PFD) is used to expand the pull-in range to meet the wide tuning range of a VCO required by process-voltage-temperature (PVT) variation. SMIC 0. 18-μm CMOS technology is adopted and the core area is 170 μm ×270 μm. Measurements show that, under a 1.8 V supply voltage, it consumes only about 90 mW, and has an input sensitivity of less than 25 mV, an output single-ended swing of above 300 mV, a phase noise of - 114 dBc/Hz at 1 MHz offset and a pull-in range of 1 GHz.
采用标准0.18 μm CMOS工艺,设计了一种高锁定范围的半盲型过采样时钟数据恢复电路.该时钟数据恢复电路(Clock and Data Recovery,CDR)主要由鉴频器(Frequency detector,FD)、多路平行过采样电路、10位数模转换器(Digital To Analog Converter,DAC)、低通滤波器(Low Pass Filter,LPF)、多相位压控振荡器(Voltage Controlled Oscillator,VCO)等构成.该CDR电路采用模数混合设计方法,并提出了基于双环结构实现对采样时钟先粗调后微调的方法,并且在细调过程中提出了加权调相的方法缩短采样时间.仿真结果表明,该CDR电路能恢复1.25~4.00 Gbps之间的伪随机数据电路,锁定时间为2.1 μs,VCO输出的抖动为47.12 ps.