在SIP(System In a Package)系统中集成具有LVDS(Low-Voltage Differential Signal)接口的多通道高速模数转换器(Analog-to-Digital Converter,ADC)时,面临不同LVDS输出通道延时不同所导致的数据采集错误的问题,为此设计了一个多通道自...在SIP(System In a Package)系统中集成具有LVDS(Low-Voltage Differential Signal)接口的多通道高速模数转换器(Analog-to-Digital Converter,ADC)时,面临不同LVDS输出通道延时不同所导致的数据采集错误的问题,为此设计了一个多通道自适应LVDS接收器。通过采用数据时钟恢复技术产生一个多相位的采样时钟,并结合ADC的测试模式来确认每一个通道的采样相位,能够自动对每一个通道的延时分别进行调整,以达到对齐各通道采样相位点,保证数据正确采集的目的。最后,基于先进CMOS工艺进行了接收器的设计、仿真、后端设计实现和流片测试,仿真和流片后的板级测试结果均表明该接收器能够对通道延迟进行自动调节以对齐采样相位,且最大的采样相位调节范围为±3 bit,信噪比大于65 dB,满足了设计要求和应用需求。展开更多
为了满足大动态范围、高精度、低噪声地磁数据采集的发展需求,采用一种24位Σ-Δ型ADC7192用于三路数据采集的方法。该方法通过使用可编程增益阵列调理交流放大部分减小了整体电路规模和功耗。针对野外等特殊应用场所引入二次数字(模拟...为了满足大动态范围、高精度、低噪声地磁数据采集的发展需求,采用一种24位Σ-Δ型ADC7192用于三路数据采集的方法。该方法通过使用可编程增益阵列调理交流放大部分减小了整体电路规模和功耗。针对野外等特殊应用场所引入二次数字(模拟)电源、自校准、满量程校准和ADC内部滤波器,降低其噪声的同时又抑制了50 Hz工频干扰。后期硬件测试对采集数据进行了对比分析,功耗为4.35 m A、测量精度可达70μG的技术指标。展开更多
A digital background calibration technique that corrects the capacitor mismatches error is proposed for successive approximation register analog-to-digital converter (SAR ADC). The technique is implemented in SAR ADC ...A digital background calibration technique that corrects the capacitor mismatches error is proposed for successive approximation register analog-to-digital converter (SAR ADC). The technique is implemented in SAR ADC which is based on tri-level switching. The termination capacitor in the Digital-to-Analog Converter (DAC) is regarded as a reference capacitor and the digital weights of all other unit capacitors are corrected with respect to the reference capacitor. To make a comparison between the size of the unit capacitor and that of the reference capacitor, each input sample is quantized twice. The unit capacitor being calibrated is swapped with the reference capacitor during the second conversion. The difference between the two conversion results is used to correct the digital weight of the unit capacitor under calibration. The calibration technique with two reference capacitors is presented to reduce the number of parameters to be estimated. Behavior simulation is performed to verify the proposed calibration technique by using a 12-bit SAR ADC with 3% random capacitor mismatch. The simulation results show that the Signal-to-Noise and Distortion Ratio (SNDR) is improved from 57.2 dB to 72.2 dB and the Spurious Free Dynamic Range (SFDR) is improved from 60.0 dB to 85.4 dB.展开更多
文摘在SIP(System In a Package)系统中集成具有LVDS(Low-Voltage Differential Signal)接口的多通道高速模数转换器(Analog-to-Digital Converter,ADC)时,面临不同LVDS输出通道延时不同所导致的数据采集错误的问题,为此设计了一个多通道自适应LVDS接收器。通过采用数据时钟恢复技术产生一个多相位的采样时钟,并结合ADC的测试模式来确认每一个通道的采样相位,能够自动对每一个通道的延时分别进行调整,以达到对齐各通道采样相位点,保证数据正确采集的目的。最后,基于先进CMOS工艺进行了接收器的设计、仿真、后端设计实现和流片测试,仿真和流片后的板级测试结果均表明该接收器能够对通道延迟进行自动调节以对齐采样相位,且最大的采样相位调节范围为±3 bit,信噪比大于65 dB,满足了设计要求和应用需求。
文摘为了满足大动态范围、高精度、低噪声地磁数据采集的发展需求,采用一种24位Σ-Δ型ADC7192用于三路数据采集的方法。该方法通过使用可编程增益阵列调理交流放大部分减小了整体电路规模和功耗。针对野外等特殊应用场所引入二次数字(模拟)电源、自校准、满量程校准和ADC内部滤波器,降低其噪声的同时又抑制了50 Hz工频干扰。后期硬件测试对采集数据进行了对比分析,功耗为4.35 m A、测量精度可达70μG的技术指标。
文摘A digital background calibration technique that corrects the capacitor mismatches error is proposed for successive approximation register analog-to-digital converter (SAR ADC). The technique is implemented in SAR ADC which is based on tri-level switching. The termination capacitor in the Digital-to-Analog Converter (DAC) is regarded as a reference capacitor and the digital weights of all other unit capacitors are corrected with respect to the reference capacitor. To make a comparison between the size of the unit capacitor and that of the reference capacitor, each input sample is quantized twice. The unit capacitor being calibrated is swapped with the reference capacitor during the second conversion. The difference between the two conversion results is used to correct the digital weight of the unit capacitor under calibration. The calibration technique with two reference capacitors is presented to reduce the number of parameters to be estimated. Behavior simulation is performed to verify the proposed calibration technique by using a 12-bit SAR ADC with 3% random capacitor mismatch. The simulation results show that the Signal-to-Noise and Distortion Ratio (SNDR) is improved from 57.2 dB to 72.2 dB and the Spurious Free Dynamic Range (SFDR) is improved from 60.0 dB to 85.4 dB.
