scholarly journals A Low Power Sigma-Delta Modulator with Hybrid Architecture

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5309
Author(s):  
Shengbiao An ◽  
Shuang Xia ◽  
Yue Ma ◽  
Arfan Ghani ◽  
Chan Hwang See ◽  
...  

Analogue-to-digital converters (ADC) using oversampling technology and the Σ-∆ modulation mechanism are widely applied in digital audio systems. This paper presents an audio modulator with high accuracy and low power consumption by using a discrete second-order feedforward structure. A 5-bit successive approximation register (SAR) quantizer is integrated into the chip, which reduces the number of comparators and the power consumption of the quantizer compared with flash ADC-type quantizers. An analogue passive adder is used to sum the input signals and it is embedded in a SAR ADC composed of a capacitor array and a dynamic comparator which has no static power consumption. To validate the design concept, the designed modulator is developed in a 180 nm CMOS process. The peak signal to noise distortion ratio (SNDR) is calculated as 106 dB and the total power consumption of the chip is recorded as 3.654 mW at the chip supply voltage of 1.8 V. The input sine wave of 0 to 25 kHz is sampled at a sampling frequency of 3.2 Ms/s. Moreover, the results achieve a 16-bit effective number of bits (ENOB) when the amplitude of the input signal is varied between 0.15 and 1.65 V. By comparing with other modulators which were realized by a 180 nm CMOS process, the proposed architecture outperforms with lower power consumption.

2018 ◽  
Vol 7 (2.16) ◽  
pp. 38
Author(s):  
Anshu Gupta ◽  
Lalita Gupta ◽  
R K. Baghel

A second-order sigma delta modulator that uses an operational transconductance amplifier as integrator and latch comparator as quantizer. The proposed technique where a low power high gain OTA is used as integrator and another circuit called dynamic latch comparator with two tail transistors and two controlling switches are used to achieve high speed, low power and high resolution in second order delta sigma modulator. It enhances the power efficiency and compactness of the modulator by implementing these blocks as sub modules. A second order modulator has been designed to justify the effectiveness of the proposed design. Technology 180nm CMOS process is used to implement complete second order continuous time sigma delta modulator.  We introduce the sub threshold three stage OTA, which is a way of achieving low distortion operation with input referred noise at 1 KHz is equal to the 2.2647pV/   and with low power consumption of 296.72nW.  A high-speed, low-voltage and a low-power Double-Tail dynamic comparator is also proposed. The proposed structure is contrasted with past dynamic comparators. In this paper, the comparator’s delay will be investigated and systematic analysis are inferred. a novel comparator using two tail transistor is proposed, here circuitry of a customized comparator having two tail is changed for low power dissipation and also it operates fast at little supply voltages. By maintaining the outline and by including couple of transistors, during the regeneration strengthening of positive feedback can be maintained, this results in amazingly diminished delay parameter. It is investigated that in proposed design structure of comparator using two tail transistors, power consumption is reduced and delay time is also diminished to a great extent. The proposed comparator is having maximum clock frequency that is possibly expanded up to 1GHz at voltages of 1 V whereas it is dissipating 10.99 µW of power, individually. By using sub threshold three stage OTA and dynamic standard two tail latch comparator, designed second order sigma delta ADC will consume 29.95µW of power.


Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5285
Author(s):  
Juyong Lee ◽  
Younggyun Oh ◽  
Sein Oh ◽  
Hyungil Chae

A CMOS (Complementary metal-oxide-semiconductor) Hall sensor with low power consumption and simple structure is introduced. The tiny magnetic signal from Hall device could be detected by a high-resolution delta-sigma ADC in presence of offset and flickering noise. Also, the offset as well as the flickering noise are effectively suppressed by the current spinning technique combined with double sampling switches of the ADC. The double sampling scheme of the ADC reduces the operating frequency and helps to reduce the power consumption. The prototype Hall sensor is fabricated in a 0.18-µm CMOS process, and the measurement shows detection range of ±150 mT and sensitivity of 110 µV/mT. The size of active area is 0.7 mm2, and the total power consumption is 4.9 mW. The proposed system is advantageous not only for low power consumption, but also for small sensor size due to its simplicity.


2012 ◽  
Vol 229-231 ◽  
pp. 1507-1510
Author(s):  
Xiang Ning Fan ◽  
Hao Zheng ◽  
Yu Tao Sun ◽  
Xiang Yan

In this paper, a 12-bit 100MS/s pipelined ADC is designed. Capacitance flip-around structure is used in sample and hold circuit, and bootstrap structure is adopted in sampling switch which has high linearity. Progressively decreasing technology is used to reduce power consumption and circuit area, where 2.5bit/stage structure is used in the first two stages, 1.5bit/stage structure is used for 3rd to 8th stages, and at the end of the circuit is a 2bit-flash ADC. Digital calibration is designed to eliminate the offset of comparators. Switched-capacitor dynamic comparator structure is used to further reduce the power consumption. The ADC is implemented by using TSMC 0.18m CMOS process with die area be 1.23mm×2.3mm. SNDR and SFDR are 65dB and 71.3dB, when sampling at 100MHz sampling clock. The current of the circuit is 96mA under 1.8V power supply.


2012 ◽  
Vol 203 ◽  
pp. 469-473
Author(s):  
Ruei Chang Chen ◽  
Shih Fong Lee

This paper presents the design and implementation of a novel pulse width modulation control class D amplifiers chip. With high-performance, low-voltage, low-power and small area, these circuits are employed in portable electronic systems, such as the low-power circuits, wireless communication and high-frequency circuit systems. This class D chip followed the chip implementation center advanced design flow, and then was fabricated using Taiwan Semiconductor Manufacture Company 0.35-μm 2P4M mixed-signal CMOS process. The chip supply voltage is 3.3 V which can operate at a maximum frequency of 100 MHz. The total power consumption is 2.8307 mW, and the chip area size is 1.1497×1.1497 mm2. Finally, the class D chip was tested and the experimental results are discussed. From the excellent performance of the chip verified that it can be applied to audio amplifiers, low-power circuits, etc.


2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Zigang Dong ◽  
Xiaolin Zhou ◽  
Yuanting Zhang

We proposed a new method for designing the CMOS differential log-companding amplifier which achieves significant improvements in linearity, common-mode rejection ratio (CMRR), and output range. With the new nonlinear function used in the log-companding technology, this proposed amplifier has a very small total harmonic distortion (THD) and simultaneously a wide output current range. Furthermore, a differential structure with conventionally symmetrical configuration has been adopted in this novel method in order to obtain a high CMRR. Because all transistors in this amplifier operate in the weak inversion, the supply voltage and the total power consumption are significantly reduced. The novel log-companding amplifier was designed using a 0.18 μm CMOS technology. Improvements in THD, output current range, noise, and CMRR are verified using simulation data. The proposed amplifier operates from a 0.8 V supply voltage, shows a 6.3 μA maximum output current range, and has a 6 μW power consumption. The THD is less than 0.03%, the CMRR of this circuit is 74 dB, and the input referred current noise density is166.1 fA/Hz. This new method is suitable for biomedical applications such as electrocardiogram (ECG) signal acquisition.


Author(s):  
Ming-Cheng Liu ◽  
Paul C.-P. Chao ◽  
Soh Sze Khiong

In this paper a low power all-digital clock and data recovery (ADCDR) with 1Mhz frequency has been proposed. The proposed circuit is designed for optical receiver circuit on the battery-less photovoltaic IoT (Internet of Things) tags. The conventional RF receiver has been replaced by the visible light optical receiver for battery-less IoT tags. With this proposed ADCDR a low voltage, low power consumption & tiny IoT tags can be fabricated. The proposed circuit achieve the maximum bandwidth of 1MHz, which is compatible with the commercial available LED and light sensor. The proposed circuit has been fabricated in TSMC 0.18um 1P6M standard CMOS process. Experimental results show that the power consumption of the optical receiver is approximately 5.58uW with a supply voltage of 1V and the data rate achieves 1Mbit/s. The lock time of the ADCDR is 0.893ms with 3.31ns RMS jitter period.


Electronics ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 1429 ◽  
Author(s):  
Jin-Fa Lin ◽  
Cheng-Yu Chan ◽  
Shao-Wei Yu

In this paper, a novel latch-adder based multiplier design, targeting low voltage and low power IoT applications is presented. It employs a semi-dynamic (dynamic circuit with static keeper circuit) full adder design which efficiently incorporates the level sensitive latch circuit with the adder cell. Latch circuit control signals are generated by a chain of delay cell circuits. They are applied to each row of the adder array. This row-wise alignment ensures an orderly procedure, while successfully removing spurious switching resulting in reduced power consumption. Due to the delay cell circuit of our design is also realized by using full adder. Therefore, it is unnecessary to adjust the transistor sizes of the delay cell circuit deliberately. Post-layout simulation results on 8 × 8 multiplier design show that the proposed design has the lowest power consumption of all design candidates. The total power consumption saving compared to conventional array multiplier designs is up to 38.6%. The test chip measurement shows successful operations of our design down to 0.41 V with a power consumption of only 427 nW with a maximum frequency 500 KHz.


Sensors ◽  
2020 ◽  
Vol 20 (13) ◽  
pp. 3649
Author(s):  
Minhyun Jin ◽  
Hyeonseob Noh ◽  
Minkyu Song ◽  
Soo Youn Kim

In this paper, we propose a complementary metal-oxide-semiconductor (CMOS) image sensor (CIS) that has built-in mask circuits to selectively capture either edge-detection images or normal 8-bit images for low-power computer vision applications. To detect the edges of images in the CIS, neighboring column data are compared in in-column memories after column-parallel analog-to-digital conversion with the proposed mask. The proposed built-in mask circuits are implemented in the CIS without a complex image signal processer to obtain edge images with high speed and low power consumption. According to the measurement results, edge images were successfully obtained with a maximum frame rate of 60 fps. A prototype sensor with 1920 × 1440 resolution was fabricated with a 90-nm 1-poly 5-metal CIS process. The area of the 4-shared 4T-active pixel sensor was 1.4 × 1.4 µm2, and the chip size was 5.15 × 5.15 mm2. The total power consumption was 9.4 mW at 60 fps with supply voltages of 3.3 V (analog), 2.8 V (pixel), and 1.2 V (digital).


2018 ◽  
Vol 27 (13) ◽  
pp. 1850206 ◽  
Author(s):  
Qingshan Yang ◽  
Peiqing Han ◽  
Niansong Mei ◽  
Zhaofeng Zhang

A 16.4[Formula: see text]nW, sub-1[Formula: see text]V voltage reference for ultra-low power low voltage applications is proposed. This design reduces the operating voltage to 0.8[Formula: see text]V by a BJT voltage divider and decreases the silicon area considerably by eliminating resistors. The PTAT and CTAT are based on SCM structures and a scaled-down [Formula: see text], respectively, to improve the process insensitivity. This work is fabricated in 0.18[Formula: see text][Formula: see text]m CMOS process with a total area of 0.0033[Formula: see text]mm2. Measured results show that it works properly for supply voltage from 0.8[Formula: see text]V to 2[Formula: see text]V. The reference voltage is 467.2[Formula: see text]mV with standard deviation ([Formula: see text]) being 12.2 mV and measured TC at best is 38.7[Formula: see text]ppm/[Formula: see text]C ranging from [Formula: see text]C to 60[Formula: see text]C. The total power consumption is 16.4[Formula: see text]nW under the minimum supply voltage at 27[Formula: see text]C.


1996 ◽  
Vol 07 (02) ◽  
pp. 305-322
Author(s):  
KAI-YUAN CHAO ◽  
D. F. WONG

In this paper, a floorplanner for low power design is presented. Our objective is to optimize total power consumption and area during the selection and placement of various implementations for circuit modules. Furthermore, the proposed method considers performance requirements, power line noises, and distribution of power consumption in order to generate lower and evenly distributed power dissipation over the resulting circuit floorplan with a specified performance. For a set of benchmark circuits we tested, on the average, our floorplanner can achieve decreases of total power consumption, wire-length, and power/ground network size by 18.3%, 4.6%, and 24%, respectively, at the cost of an area increase of 8.8% when compared with an existing area/wire-length driven floorplanner.


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