A 12-bit current steering DAC with 2-dimensional gradient-error tolerant switching scheme

A 12-bit intrinsic accuracy digital-to-analog converter integrated into standard digital 0.18μm CMOS technology is proposed.It is based on a current steering segmented 6+6 architecture and requires no calibration.By dividing one most significant bit unary source into 16 elements located in 16 separated regions of the array,the linear gradient errors and quadratic errors can be averaged and eliminated effectively.A novel static performance testing method is proposed.The measured differential nonlinearity ...     

An 8-bit 20-MS/s ZCBC Time-Domain Analog-to-Digital Data Converter

An 8-bit 20-MS/s time-domain analog-to-digital data converter (ADC) using the zero-crossing-based circuit technique is presented. Compared with the conventional ADCs, signal processing is executed in both the voltage and time domains. Since no high-gain operational amplifier is needed, this time-domain ADC works well in a low supply voltage. The proposed ADC has been fabricated in a 0.18-mum CMOS process. Its power dissipation is 4.64 mW from a supply voltage of 1.8 V. This active area occupies 1.2 times 0.7 mm². The measured signal-to-noise-distortion ratio achieves 44.2 dB at an input frequency of 10 MHz. The integral nonlinearity is less than plusmn1.07 LSB, and the differential nonlinearity is less than plusmn0.72 LSB. This time-domain ADC achieves the effective bits of 7.1 for a Nyquist input frequency at 20 MS/s.     

A 1.2?V 10-bit 60-MS/s 23?mW CMOS pipeline ADC with 0.67?pJ/conversion-step and on-chip reference voltages generator

A 1.2?V 10-bit 60?MS/s pipeline Analog-to-Digital Converter (ADC), fabricated in a 130?nm CMOS technology, is presented. The prototype is composed by five 3-bit pipeline stages and a Sample and Hold (S&H) circuit at the front. Two-stage Miller-compensated Operational Transconductance Amplifiers (OTAs), offset-compensated comparators and bootstrapping sampling switches have been used due to the low voltage supply requirements. Special attention has been paid to the reduction of the power consumption using a thorough design methodology. The converter only consumes 23?mW including on-chip reference voltages and bias current generators. The differential and integral nonlinearity of the ADC are below 0.60 and 0.61 LSBs, respectively. The pipeline converter achieves an effective resolution above 9 bits along the Nyquist bandwidth, and obtains 0.67?pJ energy consumption per conversion, making it one of the most energy-efficient 10-bit video-rate pipeline ADC reported to date.     

A 10-bit 200-MHz CMOS video DAC for HDTV applications

This paper describes a 10-bit 200-MHz CMOS current steering digital-to-analog converter (DAC) for HDTV applications. The proposed 10-bit DAC is composed of a unit decoded matrix for 6 MSBs and a binary weighted array for 4 LSB’s, considering linearity, power consumption, routing area, and glitch energy. A new switching scheme for the unit decoded matrix is developed to improve linearity further. Cascade current sources and differential switches with deglitch latch improve dynamic performance. The measured differential nonlinearity (DNL) and integral nonlinearity (INL) are 0.3 LSB and 0.2 LSB, respectively. The converter achieves a spurious-free dynamic range (SFDR) of above 55 dB over a100-MHz bandwidth and low glitch energy of 1.5 pVs. The circuit is fabricated in a 0.25 μm CMOS process and occupies 0.91 mm². When operating at 200 M Sample/s, it dissipates 82 mW from a 3.3 V power supply.     

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 high performance 90 nm CMOS SAR ADC with hybrid architecture

A 10-bit 2.5 MS/s SAR A/D converter is presented. In the circuit design, an R-C hybrid architecture D/A converter, pseudo-differential comparison architecture and low power voltage level shifters are utilized. Design chal-lenges and considerations are also discussed. In the layout design, each unit resistor is sided by dummies for good matching performance, and the capacitors are routed with a common-central symmetry method to reduce the nonlin-earity error. This proposed converter is implemented based on 90 nm CMOS logic process. With a 3.3 V analog supply and a 1.0 V digital supply, the differential and integral nonlinearity are measured to be less than 0.36 LSB and 0.69 LSB respectively. With an input frequency of 1.2 MHz at 2.5 MS/s sampling rate, the SFDR and ENOB are measured to be 72.86 dB and 9.43 bits respectively, and the power dissipation is measured to be 6.62 mW including the output drivers. This SAR A/D converter occupies an area of 238×214 μm~2. The design results of this converter show that it is suitable for multi-supply embedded SoC applications.     

一种3.3 V 9位50 MS/s CMOS流水线A/D转换器

设计了一种3.3 V 9位50 MS/s CMOS流水线A/D转换器。该A/D转换器电路采用1.5位/级,8级流水线结构。相邻级交替工作,各级产生的数据汇总至数字纠错电路,经数字纠错电路输出9位数字值。仿真结果表明,A/D转换器的输出有效位数(ENOB)为8.712位,信噪比(SNR)为54.624 dB,INL小于1 LSB,DNL小于0.6 LSB,芯片面积0.37 mm2,功耗仅为82 mW。     

A low glitch 14-b 100-MHz D/A converter

A low glitch 14-b 100-MHz current output digital-to-analog converter (DAC) is described. In addition to segmentation of the four most significant bits (MSB's) into 15 equally weighted current sources, a proportional-to-absolute-temperature (PTAT) switching voltage is applied to the current steering devices to minimize glitch over temperature. A bidirectional thin-film trim network and high β n-p-n devices reduce the amount of laser trimming required to achieve 14-b accuracy, resulting in less post-trim degradation of DAC linearity over temperature and the life of the chip. The converter has been fabricated in a 4-GHz/1.4-μm BiCMOS technology and exhibits a measured glitch energy of 0.5 pV·s (singlet). Settling time to within ±0.012% of the final value is ⩽20 ns for both rising and falling edges of a full scale step. Spurious free dynamic range (SFDR) for the described converter is 87 dBc at an update rate (f_CLK) of 10 MHz and an output frequency (f_OUT) of 2.03 MHz. The converter operates from +5 V and -5.2 V supplies and consumes 650 mW independent of conversion rate. The chip size is 4.09×4.09 mm including bond pads and electrostatic discharge (ESD) protection devices     

A Programmable 0.8-V 10-bit 60-MS/s 19.2-mW 0.13-$mu$ m CMOS ADC Operating Down to 0.5 V

This work describes a programmable 10- to 100-MS/s, low-power 10-bit two-step pipeline analog-digital converter (ADC) operating at a power supply from 0.5- to 1.2-V. MOS transistors with a low-threshold voltage are employed partially in the input sampling switches and differential pair of the SHA and MDAC for a proper signal swing margin at a 0.5-V supply. The integrated adjustable current reference optimizes the static and dynamic performance of amplifiers at 10-bit accuracy with a wide range of supply voltages. A signal-isolated layout improves the capacitor mismatch of the multiplying digital-to-analog converter, while a switched- bias power-reduction technique reduces the power dissipation of comparators in the flash ADCs. The prototype ADC in a 0.13-mum CMOS process demonstrates the measured differential nonlin- earity and integral nonlinearity within 0.35 and 0.49 least significant bits. The ADC, with an active die area of 0.98 mm², shows a maximum signal-to-noise distortion ratio and spurious free dynamic range of 56.0 and 69.6 dB, respectively, and a power consumption of 19.2 mW at a nominal condition of 0.8 V and 60 MS/s.     

A 100-MS/s 8-b CMOS subranging ADC with sustained parametricperformance from 3.8 V down to 2.2 V

A 100-MS/s 8-b CMOS analog-to-digital converter (ADC) designed for very low supply voltage and power dissipation is presented. This single-ended-input ADC is based on the unified two-step subranging architecture, which processes the coarse and fine decisions in identical signal paths to maximize their matching. However, to minimize power and area, the coarse-to-fine overlap correction has been aggressively reduced to only one LSB. The ADC incorporates five established design techniques to maximize performance: bottom-plate sampling, distributed sampling, autozeroing, interpolation, and interleaving. Very low voltage operation required for a general purpose ADC was obtained with four additional and new circuit techniques. These are a dual-gain first-stage amplifier, differential T-gate boosting, a supply independent delay generator, and a digital delay-locked-loop controlled output driver. For a clock rate of 100 MS/s, 7.0 (7.3) effective bits for a 50 MHz (10 MHz) input are maintained from 3.8 V down to 2.2 V. At 2.2 V, this 100-MS/s converter dissipates 75 mW plus 9 mW for the reference ladder. For a typical supply of 2.7 V, it consumes just 1 mW per MS/s over the 10-160-MS/s clock frequency range. Differential nonlinearity below 0.5 LSB is maintained from 2.7 V down to 2.2 V, and it degrades only slightly to 0.8 LSB at 3.8-V supply. The converter is implemented in a 0.35-μm CMOS process, with double-poly capacitors and no low-threshold devices     

A low-glitch binary-weighted DAC with delay compensation scheme

This paper presents a high-speed, low-glitch, and low-power design for a 10-bit binary-weighted current-steering digital-to-analog converter (DAC). Instead of using large input buffers to drive a lot of current switches and re-timing latches, the proposed design uses variable-delay buffers with a compact layout to compensate for the delay difference among different bits, and to reduce glitch energy from 132 to 1.36 pV s during major code transitions. The measured spurious free dynamic range (SFDR) has been improved over 10 dB, as compared to DACs without variable-delay buffers. At 250 MS/s update rate, the proposed DAC achieves 56 dB SFDR for 0.67 MHz output frequency and 49 dB SFDR for 94 MHz output frequency with 50 Ω termination. For static performance, the measured integral nonlinearity (INL) and differential nonlinearity (DNL) is less than 1.6 and 1.8 LSB, respectively. The proposed DAC can be used in various applications in industry, including digital video, digital TV, wireless communication system, etc. This chip was implemented in TSMC 1P6M 0.18 μm CMOS technology and dissipates 19 mW from a single 1.8 V power supply.     

Comparator-based switched-capacitor pipelined analog-to-digital converter with comparator preset,and comparator delay compensation

We present a differential comparator-based switched-capacitor (CBSC) pipelined analog-to-digital converter (ADC) with comparator preset, and comparator delay compensation. Compensating for the comparator delay by digitally adjusting the comparator threshold improves the ADC resolution from 2.5-bit to 7.05-bit. The ADC is manufactured in a 90 nm CMOS technology, with a core area of 0.85 mm × 0.35 mm, a 1.2 V supply for the core and 1.8 V for the input switches. It has an effective number of bits (ENOB) of 7.05-bit, and a power dissipation of 8.5 mW at 60 MS/s.     

一种改进的高速DAC电流开关及其控制信号的产生

系统分析了高速电流型CMOS数模转换器中电流开关对输出毛刺的影响,给出了减小输出毛刺的方法.改进了电流开关及其控制信号的产生电路.利用改进后的电路设计了一个8位数模转换器,在5V电源,满量程输出2 0mA条件下,模拟得到最大输出毛刺为3pV s,且电路在1 0 0MHz采样频率,1 0MHz信号频率下,无假信号动态范围达到53dB     

A systematic design approach for low-power 10-bit 100 MS/s pipelined ADC

A systematic design approach for low-power 10-bit, 100 MS/s pipelined analog-to-digital converter (ADC) is presented. At architectural level various per-stage-resolution are analyzed and most suitable architecture is selected for designing 10-bit, 100 MS/s pipeline ADC. At Circuit level a modified wide-bandwidth and high-gain two-stage operational transconductance amplifier (OTA) proposed in this work is used in track-and-hold amplifier (THA) and multiplying digital-to-analog converter (MDAC) sections, to reduce power consumption and thermal noise contribution by the ADC. The signal swing of the analog functional blocks (THA and MDAC sections) is allowed to exceed the supply voltage (1.8 V), which further increases the dynamic range of the circuit. Charge-sharing comparator is proposed in this work, which reduces the dynamic power dissipation and kickback noise of the comparator circuit. The bootstrap technique and bottom plate sampling technique is employed in THA and MDAC sections to reduce the nonlinearity error associated with the input signal resulting in a signal-to-noise-distortion ratio of 58.72/57.57 dB at 2 MHz/Nyquist frequency, respectively. The maximum differential nonlinearity (DNL) is +0.6167/−0.3151 LSB and the maximum integral nonlinearity (INL) is +0.4271/−0.4712 LSB. The dynamic range of the ADC is 58.72 dB for full-scale input signal at 2 MHz input frequency. The ADC consumes 52.6 mW at 100 MS/s sampling rate. The circuit is implemented using UMC-180 nm digital CMOS technology.     

A high-frequency and high-resolution fourth-order /spl Sigma//spl Delta/ A/D converter in BiCMOS technology

A high-performance cascaded sigma-delta modulator is presented. It has a new three-stage fourth-order topology and provides functionally a maximum signal to quantization noise ratio of 16 bits and 16.5-bit dynamic range with an oversampling ratio of only 32. This modulator is implemented with fully differential switch-capacitor circuits and is manufactured in a 2-/spl mu/m BiCMOS process. The converter, operated from +/-2.5 V power supply, +/-1.25 V reference voltage and oversampling clock of 48 MHz, achieves 97 dB resolution at a Nyquist conversion rate of 1.5 MHz after comb-filtering decimation. The power consumption of the converter is 180 mW.<>     

14位50MS/s100mW0.18μm CMOS流水线ADC

实现了一种14位40MS/s CMOS流水线A/D转换器(ADC)。在1.8V电源电压下,该ADC功耗仅为100mW。基于无采样/保持放大器前端电路和双转换MDAC技术,实现了低功耗设计,其中,无采样/保持放大器前端电路能降低约50%的功耗,双转换MDAC能降低约10%的功耗。该ADC采用0.18μm CMOS工艺制作,芯片尺寸为2.5mm×1.1mm。在40MS/s采样速率、10MHz模拟输入信号下进行测试,电源电压为1.8V,DNL在±0.8LSB以内,INL在±3.5LSB以内,SNR为73.5dB,SINAD为73.3dB,SFDR为89.5dBc,ENOB为11.9位,THD为-90.9dBc。该ADC能够有效降低SOC系统、无线通信系统及数字化雷达的功耗。     

A 1.4-V 25-Mw 600-MS/s 6-bit folding and interpolating ADC in 0.13-μm CMOS

A 600-MSample/s 6-bit folding and interpolating analog-to-digital converter (ADC) is presented. This ADC with single track-and-hold (T/H) circuits is based on cascaded folding amplifiers and input-connection-improved active interpolating amplifiers. The prototype ADC achieves 5.55 bits of the effective number of bits (ENOB) and 47.84 dB of the spurious free dynamic range (SFDR) at 10-MHz input and 4.3 bit of ENOB and 35.65 dB of SFDR at 200-MHz input with a 500 MS/s sampling rate; it achieves 5.48 bit of ENOB and 43.52 dB of SFDR at 1-MHz input and 4.66 bit of ENOB and 39.56 dB of SFDR at 30. 1-MHz input with a 600-MS/s sampling rate. This ADC has a total power consumption of 25 mW from a 1.4 V supply voltage and occupies 0.17 mm~2 in the 0.13-μm CMOS process.     

A 10-bit 100-MS/s CMOS pipelined folding A/D converter

This paper presents a 10-bit 100-MSample/s analog-to-digital（A/D） converter with pipelined folding architecture.The linearity is improved by using an offset cancellation technique and a resistive averaging interpolation network.Cascading alleviates the wide bandwidth requirement of the folding amplifier and distributed interstage track/hold amplifiers are used to realize the pipeline technique for obtaining high resolution.In SMIC 0.18μm CMOS,the A/D converter is measured as follows:the peak integral nonlinearity and differential nonlinearity are±0.48 LSB and±0.33 LSB,respectively.Input range is 1.0 V_P-P with a 2.29 mm² active area.At 20 MHz input @ 100 MHz sample clock,9.59 effective number of bits,59.5 dB of the signal-to-noise-and-distortion ratio and 82.49 dB of the spurious-free dynamic range are achieved.The dissipation power is only 95 mW with a 1.8 V power supply.     

A cost-efficient high-speed 12-bit pipeline ADC in 0.18-/spl mu/m digital CMOS

A 12-bit pipeline ADC fabricated in a 0.18-/spl mu/m pure digital CMOS technology is presented. Its nominal conversion rate is 110 MS/s and the nominal supply voltage is 1.8 V. The effective number of bits is 10.4 when a 10-MHz input signal with 2V/sub P-P/ signal swing is applied. The occupied silicon area is 0.86 mm/sup 2/ and the power consumption equals 97 mW. A switched capacitor bias current generator scales the opamp bias currents automatically with the conversion rate, which gives scaleable power consumption and full performance of the ADC from 20 to 140 MS/s.     

A 12-bit 100 MS/s pipelined ADC with digital background calibration

This paper presents a 12-bit 100 MS/s CMOS pipelined analog-to-digital converter (ADC) with digital background calibration. A large magnitude calibration signal is injected into the multiplying digital-to-analog converter (MDAC) while the architecture of the MDAC remains unchanged. When sampled at 100 MS/s, it takes only 2.8 s to calibrate the 12-bit prototype ADC and achieves a peak spurious-free dynamic range of 85 dB and a peak signal-to-noise plus distortion ratio of 66 dB with 2 MHz input. Integral nonlinearity is improved from 1.9 to 0.6 least significant bits after calibration. The chip is fabricated in a 0.18μm CMOS process, occupies an active area of 2.3×1.6 mm~2, and consumes 205 mW at 1.8 V.