scholarly journals A Design of Low-Power 10-bit 1-MS/s Asynchronous SAR ADC for DSRC Application

Electronics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1100
Author(s):  
Deeksha Verma ◽  
Khuram Shehzad ◽  
Danial Khan ◽  
Sung Jin Kim ◽  
Young Gun Pu ◽  
...  
Keyword(s):  
Low Power ◽  
Sampling Rate ◽  
Complementary Metal Oxide Semiconductor ◽  
Sar Adc ◽  
Oxide Semiconductor ◽  
Digital To Analog Converter ◽  
Analog To Digital ◽  
Clock Generation ◽  
Analog Converter ◽  
Asynchronous Sar

A design of low-power 10-bit 1 MS/s asynchronous successive approximation register analog-to-digital converter (SAR ADC) is presented in this paper. To improve the linearity of the digital-to-analog converter (DAC) and energy efficiency, a common mode-based monotonic charge recovery (CMMC) switching technique is proposed. The proposed switching technique consumes only 63.75 CVREF2 switching energy, which is far less as compared to the conventional switching technique without dividing or adding additional switches. In addition, bootstrap switching is implemented to ensure enhanced linearity. To reduce the power consumption from the comparator, a dynamic latch comparator with a self-comparator clock generation circuit is implemented. The proposed prototype of the SAR ADC is implemented in a 55 nm CMOS (complementary metal-oxide-semiconductor) process. The proposed architecture achieves a figure of merit (FOM) of 17.4 fJ/conversion, signal-to-noise distortion ratio (SNDR) of 60.39 dB, and an effective number of bits (ENOB) of 9.74 bits with a sampling rate of 1 MS/s at measurement levels. The implemented SAR ADC consumes 14.8 µW power at 1 V power supply.

scholarly journals Noise shaping in SAR ADC

2020 ◽  
Vol 33 (1) ◽  
pp. 15-26
Author(s):  
Dmitry Osipov ◽  
Aleksandr Gusev ◽  
Vitaly Shumikhin ◽  
Steffen Paul
Keyword(s):  
Power Efficiency ◽  
Sampling Rate ◽  
Complementary Metal Oxide Semiconductor ◽  
Sar Adc ◽  
Oxide Semiconductor ◽  
Noise Shaping ◽  
Digital To Analog Converter ◽  
Analog To Digital ◽  
Noise Transfer Function ◽  
Adc Architectures

The successive approximation register (SAR) analog-to-digital converter (ADC) is currently the most popular type of ADC architecture, owing to its power efficiency. They are also used in multichannel systems, where power efficiency is of high importance because of the large number of simultaneously working channels. However, the SAR ADC architecture is not the most area efficient. In SAR ADCs, the binary weighted capacitive digital-to-analog converter (DAC) is used, which means that one additional bit of resolution costs double the increase of area. Oversampling and noise shaping are methods that allow an increase in resolution without an increase of area. In this paper we present the new SAR ADC architectures with a noise shaping. A first-order noise transfer function (NTF) with zero located nearly at one can be achieved. We propose two modifications of the architecture: with zero-only NTF and with the NTF with additional pole. The additional pole theoretically increases the efficiency of noise shaping to further 3 dB. The architectures were applied to the design of SAR ADCs in a 65 nm complementary metal-oxide semiconductor (CMOS) with OSR equal to 10. A 6-bit capacitive DAC was used. The proposed architectures provide nearly 4 additional bits in ENOB. The equalent input bandwitdth is equal to 200 kHz with the sampling rate equal to 4 MS/s.

scholarly journals A 2.6 GS/s 8-Bit Time-Interleaved SAR ADC in 55 nm CMOS Technology

Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 305 ◽  
Author(s):  
Dong Wang ◽  
Xiaoge Zhu ◽  
Xuan Guo ◽  
Jian Luan ◽  
Lei Zhou ◽  
...  
Keyword(s):  
High Speed ◽  
Complementary Metal Oxide Semiconductor ◽  
Cmos Technology ◽  
Sar Adc ◽  
Oxide Semiconductor ◽  
Power Measurement ◽  
Cmos Process ◽  
Analog To Digital ◽  
Full Speed ◽  
Time Interleaved

This paper presents an eight-channel time-interleaved (TI) 2.6 GS/s 8-bit successive approximation register (SAR) analog-to-digital converter (ADC) prototype in a 55-nm complementary metal-oxide-semiconductor (CMOS) process. The channel-selection-embedded bootstrap switch is adopted to perform sampling times synchronization using the full-speed master clock to suppress the time skew between channels. Based on the segmented pre-quantization and bypass switching scheme, double alternate comparators clocked asynchronously with background offset calibration are utilized in sub-channel SAR ADC to achieve high speed and low power. Measurement results show that the signal-to-noise-and-distortion ratio (SNDR) of the ADC is above 38.2 dB up to 500 MHz input frequency and above 31.8 dB across the entire first Nyquist zone. The differential non-linearity (DNL) and integral non-linearity (INL) are +0.93/−0.85 LSB and +0.71/−0.91 LSB, respectively. The ADC consumes 60 mW from a 1.2 V supply, occupies an area of 400 μm × 550 μm, and exhibits a figure-of-merit (FoM) of 348 fJ/conversion-step.

A Noise Reduction 12-bit 125-MSPS SAR ADC with Modified Asynchronous Logic Regulation Technique

2020 ◽  
pp. 2150040
Author(s):  
Daiguo Xu ◽  
Han Yang ◽  
Xing Sheng ◽  
Ting Sun ◽  
Guangbing Chen ◽  
...  
Keyword(s):  
Noise Reduction ◽  
Feedback Loop ◽  
Cmos Technology ◽  
Sar Adc ◽  
Dynamic Comparator ◽  
Digital To Analog Converter ◽  
Analog To Digital ◽  
Asynchronous Logic ◽  
Analog Converter ◽  
Nyquist Rate

This paper presents noise reduction and modified asynchronous logic regulation techniques used in successive approximation register (SAR) analog-to-digital converter (ADC). With a transconductance enhanced structure, noise reduction is provided in the dynamic comparator. The input referred noise of the proposed comparator is about 165[Formula: see text][Formula: see text]V rms at 60∘C (typical corner). An enhanced-positive-feedback loop is introduced to reduce the regeneration delay of the comparator. In addition, a modified asynchronous logic regulation technique is exhibited, a clock with adaptable delay is driving the comparator in approximation phase. Consequently, the settling accuracy of DAC (Digital-to-Analog Converter) is enough and the conversion speed of SAR ADC is increased without any redundant cycles. To demonstrate the proposed techniques, a design of SAR ADC is fabricated in 65-nm CMOS technology, consuming 4[Formula: see text]mW from 1.2[Formula: see text]V power supply with a [Formula: see text][Formula: see text]dB and [Formula: see text][Formula: see text]dB. The proposed ADC core occupies an active area of 0.048[Formula: see text]mm2, and the corresponding FoM is 27.2[Formula: see text]fJ/conversion-step at Nyquist rate.

scholarly journals Design and Implementation of High Speed and Low Power 12-bit SAR ADC using 22nm FinFET

2022 ◽  
Vol 17 ◽  
pp. 1-15
Author(s):  
G. Vasudeva ◽  
B. V. Uma
Keyword(s):  
Low Power ◽  
High Speed ◽  
Performance Metrics ◽  
Sampling Rate ◽  
Geometrical Parameters ◽  
Design Strategies ◽  
Digital To Analog Converter ◽  
Analog To Digital ◽  
Transconductance Amplifier ◽  
And Performance

Successive Approximation Register (SAR) Analog to Digital Converter (ADC) architecture comprises of sub modules such as comparator, Digital to Analog Converter and SAR logic. Each of these modules imposes challenges as the signal makes transition from analog to digital and vice-versa. Design strategies for optimum design of circuits considering 22nm FinFET technology meeting area, timing, power requirements and ADC metrics is presented in this work. Operational Transconductance Amplifier (OTA) based comparator, 12-bit two stage segmented resistive string DAC architecture and low power SAR logic is designed and integrated to form the ADC architecture with maximum sampling rate of 1 GS/s. Circuit schematic is captured in Cadence environment with optimum geometrical parameters and performance metrics of the proposed ADC is evaluated in MATLAB environment. Differential Non Linearity and Integral Non Linearity metrics for the 12-bit ADC is limited to +1.15/-1 LSB and +1.22/-0.69 LSB respectively. ENOB of 10.1663 with SNR of 62.9613 dB is achieved for the designed ADC measured for conversion of input signal of 100 MHz with 20dB noise. ADC with sampling frequency upto 1 GSps is designed in this work with low power dissipation less than 10 mW.

scholarly journals Design of a Memristor-Based Digital to Analog Converter (DAC)

Electronics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 622
Author(s):  
Ghazal A. Fahmy ◽  
Mohamed Zorkany
Keyword(s):  
Dynamic Range ◽  
Sar Adc ◽  
Large Area ◽  
Digital To Analog Converter ◽  
Analog To Digital ◽  
Low Area ◽  
Switching Power ◽  
Analog Converter ◽  
Low Threshold ◽  
Digital To Analog

A memristor element has been highlighted in recent years and has been applied to several applications. In this work, a memristor-based digital to analog converter (DAC) was proposed due to the fact that a memristor has low area, low power, and a low threshold voltage. The proposed memristor DAC depends on the basic DAC cell, consisting of two memristors connected in opposite directions. This basic DAC cell was used to build and simulate both a 4 bit and an 8 bit DAC. Moreover, a sneak path issue was illustrated and its solution was provided. The proposed design reduced the area by 40%. The 8 bit memristor DAC has been designed and used in a successive approximation register analog to digital converter (SAR-ADC) instead of in a capacitor DAC (which would require a large area and consume more switching power). The SAR-ADC with a memristor-based DAC achieves a signal to noise and distortion ratio (SNDR) of 49.3 dB and a spurious free dynamic range (SFDR) of 61 dB with a power supply of 1.2 V and a consumption of 21 µW. The figure of merit (FoM) of the proposed SAR-ADC is 87.9 fj/Conv.-step. The proposed designs were simulated with optimized parameters using a voltage threshold adaptive memristor (VTEAM) model.

scholarly journals Implementation of a digital trim scheme for SAR ADCs

2013 ◽  
Vol 11 ◽  
pp. 227-230
Author(s):  
J. Bialek ◽  
A. Wickmann ◽  
F. Ohnhaeuser ◽  
G. Fischer ◽  
R. Weigel ◽  
...  
Keyword(s):  
Transfer Function ◽  
Power Consumption ◽  
Successive Approximation ◽  
Sar Adc ◽  
Production Test ◽  
Digital To Analog Converter ◽  
Analog To Digital ◽  
Capacitor Array ◽  
Capacitor Mismatch ◽  
Analog Converter

Abstract. Successive approximation register (SAR) analog-to-digital Converters (ADC) are based on a capacitive digital-to-analog converter (CDAC) (McCreary and Gray, 1975). The capacitor mismatch in the capacitor array of the CDAC impacts the differential non-linearity (DNL) of the ADC directly. In order to achieve a transfer function without missing codes, trimming of the capacitor array becomes necessary for SAR ADCs with a resolution of more than 12 bit. This article introduces a novel digital approach for trimming. DNL measurements of an 18 bit SAR ADC show that digital trimming allows the same performance as analog trimming. Digital trimming however reduces the power consumption of the ADC, the die size and the required time for the production test.

Energy and time-efficient circuitry of bat-bootstrap and comp-lifier for ultra-low power SAR-ADC

Circuit World ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Muhammad Yasir Faheem ◽  
Shun'an Zhong ◽  
Muhammad Basit Azeem ◽  
Xinghua Wang
Keyword(s):  
Low Power ◽  
Supply Voltage ◽  
Sampling Rate ◽  
Sar Adc ◽  
Oxide Semiconductor ◽  
Bone Block ◽  
Technological Advancement ◽  
Left Wing ◽  
Ultra Low Power ◽  
Content Type

Purpose Successive Approximation Register-Analog to Digital Converter (SAR-ADC) has been achieved notable technological advancement since the past couple of decades. However, it’s not accurate in terms of size, energy, and time consumption. Many projects proposed to make it energy efficient and time-efficient. Such designs are unable to deliver two parallel outputs. Design/methodology/approach To this end, this study introduced an ultra-low-power circuitry for the two blocks (bootstrap and comparator) of 11-bit SAR-ADC. The bootstrap has three sub-parts: back-bone, left-wing and right-wing, named as bat-bootstrap. The comparator block has a circuitry of the two comparators and an amplifier, named as comp-lifier. In a bat-bootstrap, the authors plant two capacitors in the back-bone block to avoid the patristic capacitance. The switching system of the proposed design highly synchronized with the short pulses of the clocks for high accuracy. This study simulates the proposed circuits using a built-in Cadence 90 nm Complementary Metal Oxide Semiconductor library. Findings The results suggested that the response time of two bat-bootstrap wings and comp-lifier are 80 ns, 120 ns, and 90 ns, respectively. The supply voltage is 0.7 V, wherever the power consumption of bat-bootstrap, comp-lifier and SAR-ADC are 0.3561µW, 0.257µW and 35.76µW, respectively. Signal to Noise and Distortion Ratio is 65 dB with 5 MHz frequency and 25 KS/s sampling rate. The input referred noise of the amplifier and two comparators are 98µVrms, 224µVrms and 224µVrms, respectively. Originality/value Two basic circuit blocks for SAR-ADC are introduced, which fulfill the duality approach and delivered two outputs with highly synchronized clock pulses. The circuit sharing concept introduced for the high performance SAR-ADCs.

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