10bit 100M低功耗时间交织运放共享模数转换器设计

本文设计了一个应用于3G接收机中频的10比特100兆采样率的双通道时间交织流水线模数转换器,为了降低功耗,运放在两通道间共享。针对通道间的直流失调失配,增益失配以及采样时间偏差,设计分别采用共享运放,增加每个通道转换精度以及全局采样技术来加以解决。通过改变时序,消除了输出开关电荷注入以及断开开关的电容造成的串扰,从而提高了整个模数转换器的线性度。整个模数转换器的供电电压为3.3V,功耗为70毫瓦,采用了180纳米CMOS工艺,面积为3×2mm2,在奈奎斯特频率以内,其杂散无失真动态范围大于70dB,其信杂比大于56dB。     

An energy-efficient reconfigurable analog-to-digital converter for orthopedic implants

This paper presents a pipelined analog to digital converter (ADC) with reconfigurable resolution and sampling rate for biomedical applications. Significant power saving is achieved by turning off the sample-and-hold stage and the first two pipeline stages of the ADC instead of turning off the last two stages. The reconfiguration scheme allows having three modes of operation with variable resolutions and sampling rates. Reconfigurable operational transconductance amplifiers and an interference elimination technique have been employed to optimize power-speed-accuracy performance in biomedical instrumentation. The proposed ADC exhibits a 56.9 dB SNDR with 35.4 mW power consumption in 10-bit, 40 MS/s mode and 49.2 dB SNDR with only 7.9 mW power consumption in 8-bit, 2.5 MS/s mode. The area of the core layout is 1.9 mm² in a 0.35 μm bulk-CMOS process.     

一种用于14位250 MS/s ADC的3.5 Gb/s发送器

提出了一种用于14位250 MS/s ADC的数据发送器。该发送器输出采用电流模驱动方式,最高数据传输速率达3.5 Gb/s,数据输出仅需要2个数据端口。电路采用180 nm 1.8 V 1P5M CMOS工艺实现。测试结果表明,该发送器在3.5 Gb/s速率下的输出信号摆幅为800 mV,抖动峰峰值为100 ps,功耗为32 mW。采用该3.5 Gb/s数据发送器的ADC在250 MHz采样率下得到的信噪比为71.1 dBFS,无杂散动态范围为77.6 dB。     

An ultra low area asynchronous combo 4/8/12-bit/quaternary A/D converter based on integer division

An asynchronous A/D Converter architecture based on a binary tree structure is presented in this paper. Two alternative design strategies are presented that lead either to a high mismatch immunity ADC that requires a light calibration logic (area: 0.123 mm², power: 72 mW) or a faster, tinier and even lower power ADC (area: 0.21 mm², power: 25 mW) with lower mismatch immunity that needs a slightly more complicated calibration logic. Both alternative ADC design strategies require at least one or two orders of magnitude lower area than any known approach and a remarkable low power consumption without sacrificing speed. The designed A/D Converter can operate with a configurable resolution of either 4, 8, or 12-bits. Moreover, 6 quaternary digits or three 16-level outputs are also available from the intermediate nodes of the binary tree, for applications that require multi-valued communication lines. Simulation results prove that the peak conversion rate of the high mismatch immunity A/D design alternative exceeds 300, 230 and 225 MS/s for 4, 8 and 12-bit resolution, respectively, while the peak conversion rate of the faster design alternative is higher than 500, 440 and 420 MS/s for 4, 8 and 12-bit resolution, respectively. An appropriate sample/hold and voltage to current conversion architecture has been developed along with an intelligent output latching technique that improve the achieved signal to noise and distortion ratio by up to 7 dB. Moreover, an appropriate calibration method that extends the temperature operating range and compensates for the component mismatches is presented. The ultra low area and power consumption of the developed ADC architecture favours its employment in sensor networks while these features make its use attractive as a building block in time interleaved parallel ADCs for the achievement of ultra high speed conversion.     

An 8-bit, 200 MSPS Folding and Interpolating ADC

An 8-bit, 200 MSPS folding and interpolating analog-to-digitalconverter, ADC, has been implemented in a 1.2 µmBiCMOS-process. It achieves 7.5 effective bits with a power dissipationof 575mW. The active area is 4mm². The implementationand measured results are presented. A simple analytical modelfor the interpolation-induced nonlinearity in a folding and interpolatingADC using sinusoidal folding is presented. The bowing of thereference ladder due to interaction with the input stages isanalyzed, and analytical models are derived.     

基于流水线ADC的高速数据采集系统设计

由于流水线模数转换器（ADC）能在较低的功耗条件下实现中、高精度高速数据采样功能,因而被广泛应用于雷达、通信、医学成像、精确控制等技术领域的数据采集系统。文章介绍了流水线ADC的基本原理及其最新研究成果,并且基于流水线ADC完成了一种14位精度125Msps高速数据采集系统的设计。测试结果表明,该系统在75Msps采样...     

A 90-nm CMOS, 8-bit pipeline ADC with 60-MHz bandwidth and 125-MS/s or 250-MS/s sampling frequency

In this paper a dual operating mode 8-bit, 1.1-V pipeline ADC for Gigabit Ethernet applications is presented. In the two operating modes, the ADC features different sampling frequency (125 and 250 MHz) and power consumption (9.4 and 22.8 mW). Considering a signal bandwidth of 60 MHz in both operating modes, as required by the Gigabit Ethernet standard, the ADC achieves a SNDR always larger than 39.4 dB at 125 MHz and 38.7 dB at 250 MHz (6.25-bit and 6.13-bit ENOB, respectively), with a FoM of 0.84 pJ/conv at 125 MHz and 2.2 pJ/conv at 250 MHz. The ENOB achieved is mainly limited by clock jitter. The ADC is fabricated with a 90-nm CMOS technology, with an active area of 1.25 × 0.65 mm².     

一种10位50MS/s两级逐次逼近流水线混合型A/D转换器

本文在0.18μm CMOS工艺下,实现了一款10位50MS/s两级逐次逼近流水线混合型模数转换器（pipeline SAR ADC）。其由基于逐次逼近的增益模数单元和逐次逼近ADC组成,并采用1位冗余位放宽了子模数转换器的比较误差。通过采用逐次逼近结构,增益减半MDAC技术,动态比较器及动态逐次逼近控制逻辑,降低了模数转换器的功耗和面积。流片测试结果表明,在1.8V电源电压,50MS/s采样速率下,信噪失真比(SFDR)和功耗分别为56.04dB和5mV。     

A new pipelined analog-to-digital converter using current conveyors

A new pipelined analog-to-digital converter (ADC) using second-generation current conveyor (CCII) is presented. Two main building blocks of the pipelined ADC, sample-and-hold (S/H) circuit and multiplying digital-to-analog converter (MDAC) are constructed of CCII instead of operational amplifier (OA). Experimental results show that the proposed CCII-based pipelined ADC can work at 12.5 MHz with a 7.3-bit resolution. The DNL is within −0.4 LSB and 0.4 LSB and INL is within −0.8 LSB and 0.8 LSB, respectively. The pipelined ADC is realized in TSMC 0.35 μm CMOS technology and consumes 29 mW under a 3.3 V power supply. The core size is 0.85×0.85 mm². Sing-Yen Wu received the M.S. degree in the Department of Electronic Engineering from National Taipei University of Technology, Taipei, Taiwan, in 2005. His current research interests include CMOS pipelined analog-to-digital converters and mixed-signal integrated circuit. Lu-Po Liao received the M.S. degree in the Department of Electronic Engineering from National Taipei University of Technology, Taipei, Taiwan, in 2003. His current research interests include analog integrated circuit design and mixed-signal integrated circuit design. Chia-Chun Tsai received the Ph.D. degrees in Electrical Engineering from National Taiwan University, Taipei, Taiwan, 1991. From 1989 to 2005, he served at the Department of Electronic Engineering, National Taipei University of Technology, Taipei, Taiwan. Since 2005 he has been with the Department of Computer Science and Information Engineering, Nanhua University, Chiayi, Taiwan, where he is a Full Professor. His current research interests include VLSI design automation and mixed-signal IC designs.     

A 360 fJ/conversion-step, 14-bit, 100 MS/s,digitally background calibrated pipelined ADC in 130-nm CMOS

This paper describes a 14-bit digitally background calibrated pipeline analog-to-digital converter (ADC) implemented in a mainstream 130-nm CMOS technology. The proposed calibration technique linearizes the digital output to correct for errors resulting from capacitor mismatch, finite amplifier gain, voltage reference errors and differential offsets. The software-based calibration technique requires quite modest digital resources and its estimated dynamic power is under 1 % of the ADC power consumption. After calibration, the 14-bit ADC achieves a measured peak Signal-to-Noise-plus-Distortion-Ratio of 71.1 dB at 100 MS/s sampling rate. The worst-case integral nonlinearity is improved from 32.9 down to 4 Least-Significant-Bits after calibration. The chip occupies an active area of 1.25 mm² and the core ADC (S/H+analog+digital power) consumes 105 mW. The Figure-of-Merit is 360 fJ per conversion-step.     

A Compact 3V, 70mW, 12-bit Video-Speed CMOS ADC

A 12-bit video speed pipelined switched capacitor analog-to-digitalconverter (ADC) has been implemented in a 0.5 µmstandard CMOS process. It operates from a single 2.6–;3.3Vsupply, dissipates 23mA (independent of supply voltage) at 20MSPS and occupies only 1.1mm ². A 61dB SINAD (f_in = 4.5 MHz) and an effective resolution bandwidthof 9 MHz is achieved.     

A 25-GS/s 6-bit time-interleaved SAR ADC with design-for-test memory in 40-nm low-leakage CMOS

This paper presents a 25-GS/s 6-bit time-interleaved (TI) SAR ADC in a 40-nm CMOS low-leakage (LL) process. The prototype utilizes 4 × 12 hierarchical sampling architecture to reduce the complexity of track-and-hold circuits and the timing skew calibration. The single-channel SAR ADC adopts asynchronous processing with two alternate comparators. A partially active reference voltage buffer is designed to reduce the power consumption. The method based on sinusoidal signal approximation is employed to calibrate timing skew errors. To characterize the ultra-high-speed ADC, an on-chip design-for-test memory is designed. At 25 GS/s, the ADC achieves the SNDR of 32.18 dB for low input frequency and 27.28 dB for Nyquist frequency. The chip consumes 800 mW and occupies 1.3 × 2.6 mm², including the TI ADC core and memory.     

A 5-bit 1.8 GS/s ADC-based receiver with two-tap low-overhead embedded DFE in 130-nm CMOS

Along with CMOS technology scaling, ADC-based serial link receivers have drawn growing interest in backplane communications but power dissipation of the ADC and complex digital equalizer in such digital receivers can be a limiting factor in high-speed applications. Implementing analog embedded equalization within the front-end ADC structure can potentially relax the ADC resolution requirement and reduces the complexity of the DSP which results in a more energy-efficient receiver. In this paper, the equivalence between the speculative comparisons of a loop-unrolling DFE and an ADC with non-uniform quantization levels is utilized to propose a novel ADC-based DFE receiver structure. The equivalency partially compensates for the power overhead imposed by loop-unrolling DFE. The 5-bit prototype receiver with two-tap embedded DFE is designed, laid out and simulated in a 130-nm CMOS process with 1.8 Gbps data rate. With embedded DFE disabled, the receiver achieves 4.57-bits ENOB and 1.77 pJ/conv.-step FOM. With 1.8-Gbps signaling across a 48-in FR4 channel, the two-tap DFE enabled receiver opens the completely closed eye and allows for a 0.26 UI timing margin at a BER of 10⁻⁹. The total active area is 0.21 mm² and the ADC consumes 76 mW from a 1.2-V supply.     

A 1.8-V 67-mW 10-bit 100-MS/s pipelined ADC using time-shifted CDS technique

A time-shifted correlated double sampling (CDS) technique is proposed in the design of a 10-bit 100-MS/s pipelined ADC. This technique significantly reduces the finite opamp gain error without compromising the conversion speed, allowing the active opamp blocks to be replaced by simple cascoded CMOS inverters. Both high-speed and low-power operation is achieved without compromising the accuracy requirement. An efficient common-mode voltage control is introduced for pseudodifferential architecture which can further reduce power consumption. Fabricated in a 0.18-/spl mu/m CMOS process, the prototype 10-bit pipelined ADC occupies 2.5 mm/sup 2/ of active die area. With 1-MHz input signal, it achieves 65-dB SFDR and 54-dB SNDR at 100MS/s. For 99-MHz input signal, the SFDR and SNDR are 63 and 51 dB, respectively. The total power consumption is 67 mW at 1.8-V supply, of which analog portion consumes 45 mW without any opamp current scaling down the pipeline.     

Equalization and pre-emphasis based LVDS transceiver

This work presents an area-efficient, low-power, high data rate low voltage differential signal (LVDS) transmitter and receiver with signal quality enhancing techniques. The proposed common mode feedback scheme significantly reduces the size of the LVDS transmitter by eliminating the use of area consuming passive resistor and capacitor used for close loop stability compensation. A preemphasis technique has been introduced to enhance the transmitter output’s signal quality without significantly increasing the power draw. On the receiver part, an equalization technique has also been introduced to further enhance signal quality, increases data rate and improved jitter with relatively low power consumption. The LVDS transmitter consumes 5.4 mA of current while driving an external 100 ohm resistor with an output voltage swing of 440 mV. The chip consumes an area of 0.044 mm². This LVDS receiver has an input common mode range from 0.1 to 1.6 V. It consumes 34 mW of power with a maximum data rate of 2 Gbps. It consumes an area of 0.147 mm² a jitter of 11.74 ps rms. A test chip is implemented using 0.18 μm CMOS process.     

A 1.5 V 12-bit 16 MSPS CMOS Pipelined ADC with 68 dB Dynamic Range

A 1.5 V, 12-bit, 16 MSPS analog-to-digital converter was implemented in 0.25 μm 1P5 M standard CMOS process with MIM capacitors. The converter achieves a peak SNDR of 66.5 dB with 5.12 MSPS and that of 63.0 dB with 16.384 MSPS. The dynamic range is 68 dB under both sampling rates. The maximum INL of ±0.8 LSB and DNL of ±0.5 LSB were measured under 5.12 MSPS, while those of 16.384 MSPS decreased to ±3.1 and ±1.0 LSB, respectively. An embedded bandgap reference circuit that provides the conversion voltage range is also presented with 1.5 V supply voltage. The total power consumption of this converter was 138 mW under 16.384 MSPS or 97 mW under 5.12 MSPS. The total area of this chip is 2.8 × 2.5 mm. This chip was implemented without calibration or trimming approaches.     

A Highly Integrated CMOS Analog Baseband Transceiver With 180 MSPS 13-bit Pipelined CMOS ADC and Dual 12-bit DACs

A CMOS analog baseband transceiver with a 13-bit, 180 MSPS pipelined ADC and dual 12-bit, 180 MSPS current-steering DACs is presented. The ADC is implemented without a dedicated track-and-hold stage, utilizes a front-end 2.5-bit stage with matched MDAC/comparator tracking circuits, and demonstrates an ENOB of 10.6 bits at 15 MHz and 9.7 bits at 100 MHz, employing a low-jitter delay-lock loop for its phasing. The dual I/Q DACs show over 62 dB SFDR over the Nyquist band by utilizing a dynamic linearity enhancing architecture.     

一种10位250 MS/s电荷域流水线ADC

提出了一种高速、低功耗、小面积的10位 250 MS/s 模数转换器(ADC)。该ADC采用电荷域流水线结构,消除了高增益带宽积的跨导运算放大器,降低了ADC功耗。采用流水线逐级电荷缩减技术,降低了后级电路的电荷范围,减小了芯片面积。测试结果表明,在250 MS/s采样速率、9.9 MHz输入正弦信号的条件下,该ADC的无杂散动态范围(SFDR)为64.4 dB,信噪失真比(SNDR)为57.7 dB,功耗为45 mW。     

A low power 12-bit 30 MSPS CMOS pipeline ADC with on-chip voltage reference buffer

A 12-bit 30 MSPS pipeline analog-to-digital converter(ADC) implemented in 0.13-μm 1P8M CMOS technology is presented.Low power design with the front-end sample-and-hold amplifier removed is proposed.Except for the first stage,two-stage cascode-compensated operational amplifiers with dual inputs are shared between successive stages to further reduce power consumption.The ADC presents 65.3 dB SNR,75.8 dB SFDR and 64.6 dB SNDR at 5 MHz analog input with 30.7 MHz sampling rate.The chip dissipates 33.6 mW from 1.2 V power supply.FOM is 0.79 pJ/conv step.     

A 16-bit cascaded sigma-delta pipeline A/D converter

A low-noise cascaded multi-bit sigma-delta pipeline analog-to-digital converter （ADC） with a low over-sampling rate is presented. The architecture is composed of a 2-order 5-bit sigma-delta modulator and a cascaded 4-stage 12-bit pipelined ADC, and operates at a low 8X oversampling rate. The static and dynamic performances of the whole ADC can be improved by using dynamic element matching technique. The ADC operates at a 4 MHz clock rate and dissipates 300 mW at a 5 V/3 V analog/digital power supply. It is developed in a 0.35μm CMOS process and achieves an SNR of 82 dB.