This paper presents a design of M-band near perfect reconstructed (NPR) cosine-modulated filterbank (CMFB). The prototype filter is formulated as an interpolated finite impulse response (IFIR) filter. Suitable stretch...This paper presents a design of M-band near perfect reconstructed (NPR) cosine-modulated filterbank (CMFB). The prototype filter is formulated as an interpolated finite impulse response (IFIR) filter. Suitable stretched factor is used to provide considerable reduction in computation cost as well as minimum value of error parameters. Further minimization in errors has been achieved by applying a linear gradient optimization technique. The IFIR approach provides reduction in stopband energy as side-lobe-fall-off-rate (SLFOR) in magnitude response of the prototype filter is improved. Design examples have been included to illustrate the effectiveness of the proposed technique over the existing work.展开更多
This paper describes the design and analysis of a fully differential,gain-enhanced CMOS telescopic operational transconductance amplifier （OTA） used in a pipeline analog-to-digital converter （ADC）. Specifications ...This paper describes the design and analysis of a fully differential,gain-enhanced CMOS telescopic operational transconductance amplifier （OTA） used in a pipeline analog-to-digital converter （ADC）. Specifications of the OTA are derived from the requirements of ADC. Simulation shows that for a lpF load capacitance, this OTA achieves a high DC gain （approximately 145dB） and a wide unity-gain bandwidth （above 750MHz） at a phase margin 58°. In a configuration where the closed loop-gain is 4,the design spends about 18ns for settling with 0.05% accuracy. Simulations of this design are performed in SMIC CMOS 0.18μm technology.展开更多
This paper presents the design of a two-stage bulk-input pseudo-differential operational transconductance amplifier (OTA) and its application in active-RC filters. The OTA was designed in 90 nm CMOS process and operat...This paper presents the design of a two-stage bulk-input pseudo-differential operational transconductance amplifier (OTA) and its application in active-RC filters. The OTA was designed in 90 nm CMOS process and operates at a single supply voltage of 0.5 V. Using a two-path bulk-driven OTA by the combination of two different amplifiers the DC gain and speed of the OTA is increased. Rail-to-rail input is made possible using the transistor’s bulk terminal as in input. Also a Miller-Feed-forward (MFF) compensation is utilized which is improved the gain bandwidth (GBW) and phase margin of the OTA. In addition, a new merged cross-coupled self-cascode pair is used that can provide higher gain. Also, a novel cost-effective bulk-input common-mode feedback (CMFB) circuit has been designed. Simplicity and ability of using this new merged CMFB circuit is superior compared with state-of-the-art CMFBs. The OTA has a 70.2 dB DC gain, a 2.5 MHz GBW and a 70.8o phase margin for a 20 PF capacitive load whereas consumes only 25 μw. Finally, an 8th order Butterworth active Biquadrate RC filter has been designed and this OTA was checked by a typical switched-capacitor (SC) integrator with a 1 MHz clock-frequency.展开更多
In this paper, a new approach for the design of non-uniform frequency spacing filter bank using Simulated Annealing has been presented. The filter bank structure is obtained by merging the relevant bands of a uniforml...In this paper, a new approach for the design of non-uniform frequency spacing filter bank using Simulated Annealing has been presented. The filter bank structure is obtained by merging the relevant bands of a uniformly shifted filter bank with integer sampling factors. The design problem is formulated as a single objective unconstrained optimization problem for reducing the amplitude distortion of the overall filter bank for a specified pass-band ripple and stop-band attenuation of the prototype filter. The prototype filter coefficients are optimized using block update method to reach global optimum very quickly and the near perfect reconstruction of the filter bank is also preserved. Simulation results demonstrate that the linear-phase non-uniform filter banks designed by the proposed method have small amplitude distortions and aliasing distortions. Using this technique to minimize design objective is suitable for filter banks applied in sub-band filtering because linear phase property is assured here.展开更多
文摘This paper presents a design of M-band near perfect reconstructed (NPR) cosine-modulated filterbank (CMFB). The prototype filter is formulated as an interpolated finite impulse response (IFIR) filter. Suitable stretched factor is used to provide considerable reduction in computation cost as well as minimum value of error parameters. Further minimization in errors has been achieved by applying a linear gradient optimization technique. The IFIR approach provides reduction in stopband energy as side-lobe-fall-off-rate (SLFOR) in magnitude response of the prototype filter is improved. Design examples have been included to illustrate the effectiveness of the proposed technique over the existing work.
文摘介绍了一种全差分增益增强CMOS运算放大器的设计和实现。该放大器用于12位20 MHz采样频率的流水线模/数转换器(A/D)的采样保持电路。为了实现大的输入共模范围,采用折叠式共源共栅放大器。主放大器采用开关电容共模反馈电路,辅助放大器则采用简单的连续时间共模反馈电路。该放大器采用CMOS 0.5μm工艺,电源电压为3.3 V。Cadence Spectre仿真结果显示,在负载为6 p F的情况下,其增益为99 d B,单位增益带宽为318 MHz,相位裕度为53°。
文摘This paper describes the design and analysis of a fully differential,gain-enhanced CMOS telescopic operational transconductance amplifier （OTA） used in a pipeline analog-to-digital converter （ADC）. Specifications of the OTA are derived from the requirements of ADC. Simulation shows that for a lpF load capacitance, this OTA achieves a high DC gain （approximately 145dB） and a wide unity-gain bandwidth （above 750MHz） at a phase margin 58°. In a configuration where the closed loop-gain is 4,the design spends about 18ns for settling with 0.05% accuracy. Simulations of this design are performed in SMIC CMOS 0.18μm technology.
文摘设计了一种基于CSMC 0.25μm CMOS工艺的高性能全差分输入的折叠式共源共栅运算放大器电路。该电路由折叠式共源共栅运放模块、差分输出模块与共模负反馈模块组成,具有单位增益带宽高、稳定性好、开环增益大等优点。通过Cadance对此电路进行进一步的设计优化与仿真,表明该电路在5 V电源电压下,直流开环增益为115 d B、单位增益带宽为30 MHz、共模抑制比为185 d B、相位裕度为66°,达到了预期的设计目标。
文摘This paper presents the design of a two-stage bulk-input pseudo-differential operational transconductance amplifier (OTA) and its application in active-RC filters. The OTA was designed in 90 nm CMOS process and operates at a single supply voltage of 0.5 V. Using a two-path bulk-driven OTA by the combination of two different amplifiers the DC gain and speed of the OTA is increased. Rail-to-rail input is made possible using the transistor’s bulk terminal as in input. Also a Miller-Feed-forward (MFF) compensation is utilized which is improved the gain bandwidth (GBW) and phase margin of the OTA. In addition, a new merged cross-coupled self-cascode pair is used that can provide higher gain. Also, a novel cost-effective bulk-input common-mode feedback (CMFB) circuit has been designed. Simplicity and ability of using this new merged CMFB circuit is superior compared with state-of-the-art CMFBs. The OTA has a 70.2 dB DC gain, a 2.5 MHz GBW and a 70.8o phase margin for a 20 PF capacitive load whereas consumes only 25 μw. Finally, an 8th order Butterworth active Biquadrate RC filter has been designed and this OTA was checked by a typical switched-capacitor (SC) integrator with a 1 MHz clock-frequency.
文摘In this paper, a new approach for the design of non-uniform frequency spacing filter bank using Simulated Annealing has been presented. The filter bank structure is obtained by merging the relevant bands of a uniformly shifted filter bank with integer sampling factors. The design problem is formulated as a single objective unconstrained optimization problem for reducing the amplitude distortion of the overall filter bank for a specified pass-band ripple and stop-band attenuation of the prototype filter. The prototype filter coefficients are optimized using block update method to reach global optimum very quickly and the near perfect reconstruction of the filter bank is also preserved. Simulation results demonstrate that the linear-phase non-uniform filter banks designed by the proposed method have small amplitude distortions and aliasing distortions. Using this technique to minimize design objective is suitable for filter banks applied in sub-band filtering because linear phase property is assured here.
