A 1.2-V 19.2-mW 10-bit 30-MS/s pipelined ADC in 0.13-icm CMOS

A 10-bit 30-MS/s pipelined analog-to-digital converter (ADC) is presented.For the sake of lower power and area,the pipelined stages are scaled in current and area,and op amps are shared between the successive stages.The ADC is realized in the 0.13-tt,m 1-poly 8-copper mixed signal CMOS process operating at 1.2-V supply voltage.Design approaches are discussed to overcome the challenges associated with this choice of process and supply voltage,such as limited dynamic range,poor analog characteristic devices,the limited linearity of analog switches and the embedded sub-1-V bandgap voltage reference.Measured results show that the ADC achieves 55.1-dB signal-to-noise and distortion ratio,67.5-dB spurious free dynamic range and 19.2-mW power under conditions of 30 MSPS and 10.7-MHz input signal.The FoM is 0.33 pJ/step.The peak integral and differential nonlinearities are 1.13 LSB and 0.77 LSB,respectively.The ADC core area is 0.94 mm2.     

An Ultra-Energy-Efficient Wide-Bandwidth Video Pipeline ADC Using Optimized Architectural Partitioning

The classical pipeline analog-to-digital converter (ADC) architecture is analyzed to determine optimal partitioning for high effective resolution bandwidth (ERBW) and low-power consumption at reduced supply voltages. It is found that multibit inter-stage partitioning, in particular 2.5 bits per stage, is optimum for the reduction of power consumption in subsampling video ADCs for mobile/handheld receivers. To validate the analysis, a 1.5-V, 10-bit pipeline ADC for the digital video broadcast-handheld application was realized in a standard 3.3-V, 0.35-mum CMOS technology, with 2.5-2.5-2.5-4 partitioning employed. At the target sampling rate of 20.48 MS/s, measured results show that the converter achieves 56-dB SNR, 60-dB spurious-free dynamic range, 100-MHz ERBW and a power consumption of 19.5 mW. Energy consumption per conversion is only 0.19 pJ, making it the most energy-efficient 10-bit video-rate pipeline ADC reported to date     

A 69-mW 10-bit 80-MSample/s Pipelined CMOS ADC

A 10-bit 80-MS/s analog-to-digital converter (ADC) with an area- and power-efficient architecture is described. By sharing an amplifier between two successive pipeline stages, a 10-bit pipeline is realized using just four amplifiers with a separate sample-and-hold block. The proposed feedback signal polarity inverting (FSPI) technique addresses the drawback of the conventional amplifier sharing technique. A wide-swing wide-bandwidth telescopic amplifier and an early comparison technique with a constant delay circuit have been developed to further reduce power consumption. The ADC is implemented in a 0.18-/spl mu/m dual-gate-oxidation CMOS process technology, achieves 72.8-dBc spurious free dynamic range, 57.92-dBc signal-to-noise ratio, 9.29 effective number of bits (ENOB) for a 99-MHz input at full sampling rate, and consumes 69 mW from a 3-V supply. The ADC occupies 1.85 mm/sup 2/.     

A 10-bit 50-MS/s subsampling pipelined ADC based on SMDAC and opamp sharing

This paper describes a 10-bit,50-MS/s pipelined A/D converter(ADC) with proposed area- and power-efficient architecture.The conventional dedicated sample-hold-amplifier(SHA) is eliminated and the matching requirement between the first multiplying digital-to-analog converter(MDAC) and sub-ADC is also avoided by using the SHA merged with the first MDAC(SMDAC) architecture,which features low power and stabilization.Further reduction of power and area is achieved by sharing an opamp between two successive pi...     

A 1-V 1.25-GS/S 8-Bit Self-Calibrated Flash ADC in 90-nm Digital CMOS

We present an 8-bit 1.25-GS/s flash analog-to-digital converter (ADC) in 90-nm digital CMOS with wide analog input bandwidth and low power dissipation. The ADC employs two key techniques: a self-biased track-and-hold amplifier which enhances the ADC full-scale voltage and enables the converter operating under a single 1-V supply; and an improved calibration scheme based on reference pre-distortion to enhance the ADC linearity without sacrificing its sampling speed. The prototype converter thus achieves 7-, 6.9-, 6.5–bit ENOB at 1.25 GS/s for input signal frequencies of 10 MHz, 600 MHz, and 1.3 GHz, respectively, and better than 52-dB SFDR across the full Nyquist-band, while dissipating 207 mW from a single 1-V supply.      

An 8-b 300MS/s folding and interpolating ADC for embedded applications

A 1.4-V 8-bit 300-MS/s folding and interpolating analog-to-digital converter (ADC) is proposed. Fabricated in the 0.13-μm CMOS process and occupying only 0.6-mm2 active area, the ADC is especially suitable for embedded applications. The system is optimized for a low-power purpose. Pipelining sampling switches help to cut down the extra power needed for complete settling. An averaging resistor array is placed between two folding stages for power-saving considerations. The converter achieves 43.4-dB signal-to-noise and distortion ratio and 53.3-dB spurious-free dynamic range at 1-MHz input and 42.1-dB and 49.5-dB for Nyquist input. Measured results show a power dissipation of 34 mW and a figure of merit of 1.14 pJ/convstep at 250-MHz sampling rate at 1.4-V supply.     

A 6-bit 800-MS/s Pipelined A/D Converter With Open-Loop Amplifiers

A 6-bit 800-MS/s pipelined A/D converter (ADC) achieves SNDR and SFDR of 33.7 dB and 47.5 dB, respectively. Employing voltage-mode open-loop amplifiers in gain stages, global gain control techniques, and two-bank-interleaved architecture, the proposed pipelined A/D converter relaxes stringent design tradeoffs between speed and power. Fabricated in a 0.18-mum CMOS technology, the ADC consumes 105 mW from a 1.8-V power supply while the active area is only 0.5 mm²     

A 14-bit, 10-Msamples/s D/A converter using multibit /spl Sigma//spl Delta/ modulation

A 14-bit digital-to-analog converter based on a fourth-order multibit sigma-delta modulator is described. The digital modulator is pipelined to minimize both its power dissipation and design complexity. The 6-bit output of this modulator is converted to analog using 64 current-steering cells that are continuously calibrated to a reference current. This converter achieves 85-dB dynamic range at 5-MHz signal bandwidth, with an oversampling ratio of 12. The chip was fabricated in a 0.5-/spl mu/m CMOS technology and operates from a single 2.5-V supply.     

A wide input bandwidth 7-bit 300-MSample/s folding and current-mode interpolating ADC

A 7-bit Nyquist folding and interpolating analog-to-digital converter (ADC) that converts at 300 MSamples/s is presented. Using current-mode signal processing techniques for analog preprocessing and a front-end sample-and-hold, the proposed 7-bit folding and interpolating ADC yields a wide input bandwidth up to 60 MHz with six effective number of bits. The ADC consumes 200 mW from a 3.3-V power supply. The chip occupies 1.2 mm/sup 2/ active area, fabricated in 0.35-/spl mu/m CMOS.     

Low-power CMOS fully-folding ADC with a mixed-averaging distributed T/H circuit

This paper describes an 8-bit 125 Mhzlow-powerCMOS fully-foldinganalog-to-digital converter(ADC).A novel mixed-averaging distributed T/H circuit is proposed to improve the accuracy. Folding circuits are not only used in the fine converter but also in the coarse one and in the bit synchronization block to reduce the number of comparators for low power. This ADC is implemented in 0.5μm CMOS technology and occupies a die area of 2 × 1.5 mm~2. The measured differential nonlinearity and integral nonlinearity are 0.6 LSB/-0.8 LSB and 0.9 LSB/-1.2 LSB, respectively. The ADC exhibits 44.3 dB of signal-to-noise plus distortion ratio and 53.5 dB of spurious-free dynamic range for 1 MHz input sine-wave. The power dissipation is 138 mW at a sampling rate of 125 MHz at a 5 V supply.     

A digitally self-calibrating 14-bit 10-MHz CMOS pipelined A/Dconverter

A digitally self-calibrating pipelined analog-to-digital converter (ADC) featuring 1.5-bit/stage structure is presented. The integral (INL) and differential nonlinearity (DNL) errors are removed using a novel digital calibration algorithm, which also eliminates missing codes that can occur with other calibration algorithms near the extremes of the input range. After calibration, the measured DNL is ±0.6 LSB and the INL is ±2.5 LSB at the 14-bit level. Sampling at a 10-MHz rate, the chip dissipates 220 mW and (post-calibration) yields a signal-to-noise ratio of 77 dB and a spurious-free dynamic range of 95 dB with 4.8-MHz sine wave input signal. The chip is fabricated in 0.5-μm CMOS double-poly double-metal process, measures 3.8 mm × 3.3 mm (150 mil × 130 mil), and operates from a single 5-V supply     

An 8-bit 2-Gsample/s folding-interpolating analog-to-digital converter in SiGe technology

This paper deals with the design and implementation of an 8-bit 2-Gsample/s folding-interpolating analog-to-digital converter (ADC) using a SiGe technology with a unity gain cutoff frequency f/sub T/ of 47 GHz. The high-speed high-resolution ADC has applications in direct IF sampling receivers for wideband communication systems. The converter occupies an area of 3.5 mm/spl times/3.5 mm including pads and exhibits an effective resolution bandwidth of 700 MHz at a sampling rate of 2 Gsample/s. The maximum DNL and INL are 0.5 and 1 LSB, respectively. The ADC dissipates 3.5W (including output buffers) from a 3.3-V power supply.     

A 0.5-V 8-bit 10-Ms/s Pipelined ADC in 90-nm CMOS

This paper presents a pipelined analog-to-digital converter (ADC) operating from a 0.5-V supply voltage. The ADC uses true low-voltage design techniques that do not require any on-chip supply or clock voltage boosting. The switch OFF leakage in the sampling circuit is suppressed using a cascaded sampling technique. A front-end signal-path sample-and-hold amplifier (SHA) is avoided by using a coarse auxiliary sample and hold (S/H) for the sub-ADC and by synchronizing the sub-ADC and pipeline-stage sampling circuit. A 0.5-V operational transconductance amplifier (OTA) is presented that provides inter-stage amplification with an 8-bit performance for the pipelined ADC operating at 10 Ms/s. The chip was fabricated on a standard 90 nm CMOS technology and measures 1.2 mm times 1.2 mm. The prototype chip has eight identical stages and stage scaling was not used. It consumes 2.4 mW for 10-Ms/s operation. Measured peak SNDR is 48.1 dB and peak SFDR is 57.2 dB for a full-scale sinusoidal input. Maximal integral nonlinearity and differential nonlinearity are 1.19 and 0.55 LSB, respectively.     

A 70-mW 300-MHz CMOS continuous-time /spl Sigma//spl Delta/ ADC with 15-MHz bandwidth and 11 bits of resolution

A wide-bandwidth continuous-time sigma-delta ADC is implemented in a 0.13-/spl mu/m CMOS. The circuit is targeted for wide-bandwidth applications such as video or wireless base-stations. The active blocks are composed of regular threshold voltage devices only. The fourth-order architecture uses an OpAmp-RC-based loop filter and a 4-bit internal quantizer operated at 300-MHz clock frequency. The converter achieves a dynamic range of 11 bits over a bandwidth of 15 MHz. The power dissipation is 70 mW from a 1.5-V supply.     

A partially switched-opamp technique for high-speed low-power pipelined analog-to-digital converters

This paper presents a partially switched-opamp technique for a high-speed, low-power pipelined analog-to-digital converter (ADC). Unlike a conventional switched-opamp technique, only the second stage of a two-stage opamp is switched with the enhanced power efficiency and the drawbacks of an opamp sharing technique and a conventional switched-opamp technique are addressed. The prototype of 8-bit 200-MS/s pipelined ADC is implemented in a 0.18-/spl mu/m CMOS process technology. This converter achieves 55.8-dB spurious free dynamic range, 47.3-dB signal-to-noise-plus-distortion ratio, 7.68 effective number of bits for a 90-MHz input at full sampling rate, and consumes 30-mW from a 1.8-V supply. The active area of the ADC is 0.15 mm/sup 2/.     

A 1.4-V 10-bit 25-MS/s pipelined ADC using opamp-reset switching technique

A low-voltage opamp-reset switching technique (ORST) that does not use clock boosting, bootstrapping, switched-opamp (SO), or threshold voltage scaling is presented. This technique greatly reduces device reliability issues. Unlike the SO technique, the opamps stay active for all clock phases and, therefore, the ORST is suitable for high-speed applications. This new switching technique is applied to the design of a 10-bit 25-MS/s pipelined analog-to-digital converter (ADC). The prototype ADC was fabricated in a 0.35-/spl mu/m CMOS process and demonstrates 55-dB signal-to-noise ratio, 55-dB spurious-free dynamic range, and 48-dB signal-to-noise-plus-distortion ratio performance with a 1.4-V power supply. The total power consumption is 21 mW. The ADC's minimum operating power supply is 1.3 V (|V/sub TH,P/| = 0.9 V) and the maximum operating frequency is 32 MS/s. The ORST is fully compatible with future low-voltage submicron CMOS processes.     

A 65-mW, 10-bit, 40-Msample/s BiCMOS Nyquist ADC in 0.8 mm2

This paper describes the design of a 10-bit, 40-MSample/s analog-to-digital converter (ADC) based on a cascaded folding and interpolating architecture. The folding and interpolating factors are optimized for low power. The ADC features balanced circuit design, a newly developed shifted averaging technique, and stacked circuits for analog and digital folding. The untrimmed ADC dissipates 65 mW from a single 5-V supply. The fully differential ADC achieves 9.2 effective bits for a 1.6-V_pp input signal. Its resolution bandwidth is 20 MHz. The ADC is realized in a 7-GHz, 0.6-μm BiCMOS process and measures 0.8 mm²     

A 12-bit 40 MS/s pipelined ADC with over 80 dB SFDR

This paper describes a 12-bit 40 MS/s calibration-free pipelined analog-to-digital converter (ADC), which is optimized for high spurious flee dynamic range (SFDR) performance and low power dissipation. With a 4.9 MHz sine wave input, the prototype ADC implemented in a 0.18-μm 1P6M CMOS process shows measured differential nonlinearity and integral nonlinearity within 0.78 and 1.32 least significant bits at the 12-bit level without any trimming or calibration. The ADC, with a total die area of 3. 1 × 2.1 mm~2, demonstrates a maximum signal-to-noise distortion ratio (SNDR) and SFDR of 66.32 and 83.38 dB, respectively, at a 4.9 MHz analog input and a power consumption of 102 mW from a 1.8 V supply.     

A 14-bit intrinsic accuracy Q2 random walk CMOS DAC

In this paper, a 14-bit, 150-MSamples/s current steering digital-to-analog converter (DAC) is presented. It uses the novel Q² random walk switching scheme to obtain full 14-bit accuracy without trimming or tuning. The measured integral and differential nonlinearity performances are 0.3 and 0.2 LSB, respectively; the spurious-free dynamic range is 84 dB at 500 kHz and 61 dB at 5 MHz. Running from a single 2.7-V power supply, it has a power consumption of 70 mW for an input signal of 500 kHz and 300 mW for an input signal of 15 MHz. The DAC has been integrated in a standard digital single-poly, triple-metal 0.5-μm CMOS process. The die area is 13.1 mm²     

A Low-Power Low-Voltage 10-bit 100-MSample/s Pipeline A/D Converter Using Capacitance Coupling Techniques

This paper presents a low-power low-voltage 10-bit 100-MSample/s pipeline analog-to-digital converter (ADC) using capacitance coupling techniques. A capacitance coupling sample-and-hold stage achieves high SFDR with 1.0-V supply voltage at a high sampling rate. A capacitance coupling folded-cascode amplifier effectively saves the power consumption of the gain stages of the ADC in a 90-nm digital CMOS technology. The SNDR and the SFDR are 55.3 dB and 71.5 dB, respectively, and the power consumption is 33 mW