Design of a high speed and low area latch-based comparator in 90-nm CMOS technology having low offset voltage

Author(s):  
Satyabrata Nanda ◽  
Avipsa S. Panda ◽  
G.L.K. Moganti

Strong arm comparator has some characteristics like it devours zero static power and yields rail to rail swing. It acquires a positive feedback allowed by two cross coupled pairs of comparators and results a low offset voltage in input differential stage. We modified a strong arm Comparator for high speed without relying on complex calibration Schemes. a 5- bit 600MS/s asynchronous digital slope analog to digital converter (ADS-ADC) with modified strong arm comparator designed in cadence virtuoso at 180nm CMOS technology. The design of SR-Latch using Pseudo NMOS NOR Gate optimizes the speed. Thus delay reduced in select signal generation block. Power dissipation is minimized with lesser transistor count in Strong arm comparator and SR-Latch with maximum sampling speed. The speed of the converter can be improved by resolution. The proposed circuit is 5-bit ADC containing a delay cell, Sample and hold, continuous time comparator, strong arm comparator, Pseudo NMOS SR-Latch and Multiplexer. This 5- bit ADC operates voltage at 1.8 volts and consumes an average power.


2014 ◽  
Vol 513-517 ◽  
pp. 4572-4575
Author(s):  
Zhong Ying Zhu ◽  
Hui Hong ◽  
Shi Liang Li

A high speed, low offset fully differential comparator for high-speed analog-to-digital converter which can work at a sampling rate of 8GS/s is presented in this paper. The three-stage pre-amplifiers in the improved comparator structure is proposed to ameliorate its gain. The positive feedback regeneration circuit and the improved output buffer are used to ameliorate the comparator bandwidth. Operating with an input sine signal of 1GHz frequency, the circuit can oversample up to 8GS/s with 5bits of resolution. The simulated offset voltage of the comparator by Monte Carlo at 8GHz clock is 5.09mV.


2011 ◽  
Vol 20 (07) ◽  
pp. 1377-1387 ◽  
Author(s):  
CHIH-WEN LU ◽  
CHING-MIN HSIAO

A high-speed low-power rail-to-rail buffer amplifier, which is suitable for liquid crystal display driver applications, is proposed. An offset voltage is intentionally built in the second stage to cut off the transistors of last stage from the output node in the stable state and hence achieve low dc power consumption. The input referred offset voltage due to the built-in offset is very small. The buffer draws little current while static but has a large driving capability while transient. An experimental prototype buffer amplifier implemented in a 0.35-μm CMOS technology demonstrates that the circuit can operate under a wide power supply range. Quiescent current of 5 μA is measured. The buffer exhibits the settling time of 1.5 μs for a voltage swing of 0.1 ~ (VDD – 0.1) V under a 600 pF capacitance load. The area of this buffer is 30 × 98 μm2. The measured data show that the proposed output buffer amplifier is very suitable for LCD driver applications.


2021 ◽  
Vol 12 ◽  
pp. 1-8
Author(s):  
Sujata A. A ◽  
Lalitha. Y. S

The recent technologies in VLSI Chips have grown in terms of scaling of transistor and device parameters but still, there is challenging task for controlling current between the source and drain terminals. For effective control of device current, the FinFET transistors have come into VLSI chip, through which current can be controlled effectively. This paper is to address the issues present in CMOS technology and majorly concentrated on the proposed 4-bit Nano processor using FinFET 32nm technology by using the Cadence Virtuoso software tool. In the proposed Nano processor, the first part is to design using 4bit ALU which includes all basic and universal gates, efficient and high-speed adder, multiplier, and multiplexer. The Carry Save Adder (CSA) and multiplier are the major subcomponents which can optimize the power consumption and area reduction. The second part of the proposed Nano processor is 4-bit 6T SRAM and Encoder and decoder and also Artificial Neural Network (ANN). All these subcomponents are designed at analog transistors (Schematic level) through which the Graphic Data System (GDS-II) is generated through mask layout design. Finally, the verification and validation are done using DRC and LVS, at the last chip-level circuit is generated for chip fabrication. The ALU is designed by using CMOS inverters and the designed ALU schematic is simulated through 32nm FinFET technological library and compared with CMOS technology which is simulated through 32nm CMOS library (without FinFET). The power consumption of AND, OR, XOR, NOT, NAND gates, SRAM, Encoder, Decoder and ANN are 36.09nW, 64.970nW, 61.13nW, 33.31nW, 37.45nW, 32.5% optimization in power dissipation and 47% optimization in leakage current, 2.68uW, 1.98uW and 7.5% improvement in power consumption and 0.5% information loses compressed subsequently respectively. The basic gates and universal gates, CSA, subtraction, and MUX are integrated for 4-bit ALU design, and its delay, power consumption, and area are 0.104nsec, 314.4uW, and 56.8usqm respectively


2013 ◽  
Vol 22 (04) ◽  
pp. 1350018 ◽  
Author(s):  
ZHANGMING ZHU ◽  
HONGBING WU ◽  
GUANGWEN YU ◽  
YANHONG LI ◽  
LIANXI LIU ◽  
...  

A low offset and high speed preamplifier latch comparator is proposed for high-speed pipeline analog-to-digital converters (ADCs). In order to realize low offset, both offset cancellation techniques and kickback noise reduction techniques are adopted. Based on TSMC 0.18 μm 3.3 V CMOS process, Monte Carlo simulation shows that the comparator has a low offset voltage 1.1806 mV at 1 sigma at 125 MHz, with a power dissipation of 413.48 μW.


2012 ◽  
Vol 74 (2) ◽  
pp. 467-471 ◽  
Author(s):  
Zhangming Zhu ◽  
Guangwen Yu ◽  
Hongbing Wu ◽  
Yifei Zhang ◽  
Yintang Yang

Author(s):  
D Anil Kumar

The recent technologies in VLSI chips has grown in terms of scaling of transistor and device parameters but still there is a challenging task for controlling of current between source and drain terminals. For effective control of device current, the FinFET transistors have come into VLSI chip manufacturing, through which current can be effectively controlled. This section addresses the issues present in CMOS technology and majorly concentrated on proposed 4-bit Nano processor using FinFET 32nm technology by using Cadence Virtuoso software tool. In the proposed Nanoprocessor design, the first portion of the design is done using 4bit ALU which includes all basic and universal gates, high speed adder, multiplier and multiplexer. The Carry Save Adder (CSA) and multiplier are the major sub component which can optimize the power consumption and area reduction. The second portion of the proposed Nano processor design is 4-bit 6T SRAM and encoder and decoder and also using Artificial Neural Network (ANN). All these sub components are designed at analog transistors (Schematic level) through which the Graphic Data System (GDS-II) is generated through mask layout design. Finally, the verification and validation are done using DRC and LVS and at the last chip level circuit is generated for chip fabrication. The ALU is designed by using CMOS inverters and the designed ALU schematic is simulated through 32nm FinFET using technological library and compared with CMOS technology which is simulated through 32nm CMOS library (without FinFET). The power consumption of AND, OR, XOR, NOT, NAND gates, SRAM, Encoder, Decoder and ANN are 36.09nW, 64.970nW, 61.13nW, 33.31nW, 37.45nW, 32.5% with optimization in power dissipation of 47% along with optimization in leakage current, with 2.68uW, 1.98uW and 7.5% improvement in power consumption and 0.5% information loses are compressed subsequently respectively. The basic gates, universal gates, CSA, subtraction and MUX are integrated for 4-bit ALU design and its delay, power consumption and area are found to be 0.104nsec, 314.4uW and 56.8μsqm respectively.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Labonnah Farzana Rahman ◽  
Mamun Bin Ibne Reaz ◽  
Chia Chieu Yin ◽  
Mohammad Marufuzzaman ◽  
Mohammad Anisur Rahman

Circuit intricacy, speed, low-offset voltage, and resolution are essential factors for high-speed applications like analog-to-digital converters (ADCs). The comparator circuit with preamplifier increases the power dissipation, as it requires higher amount of currents than the latch circuitry. In this research, a novel topology of dynamic latch comparator is illustrated, which is able to provide high speed, low offset, and high resolution. Moreover, the circuit is able to reduce the power dissipation as the topology is based on latch circuitry. The cross-coupled circuit mechanism with the regenerative latch is employed for enhancing the dynamic latch comparator performance. In addition, input-tracking phase is used to reduce the offset voltage. The Monte-Carlo simulation results for the designed comparator in 0.18 μm CMOS process show that the equivalent input-referred offset voltage is 720 μV with 3.44 mV standard deviation. The simulated result shows that the designed comparator has 8-bit resolution and dissipates 158.5 μW of power under 1.8 V supply while operating with a clock frequency of 50 MHz. In addition, the proposed dynamic latch comparator has a layout size of148.80 μm×59.70 μm.


2013 ◽  
Vol 321-324 ◽  
pp. 367-371
Author(s):  
Jing Lei Han ◽  
Wen Lian Zhang ◽  
Zhi Biao Shao

A pre-amplifier for distributed track and hold (DTH) circuit in high speed and high resolution folding and interpolating analog-to-digital converter (ADC) is proposed. This scheme resolves several limitations of conventional differential difference pre-amplifier (DDPA) in low voltage supply, compared to the conventional DDPA, the proposed scheme increases the input range so that all DDPAs of DTH can operate effectively, improves the averaging effect of average network, saves the random offset voltage from device mismatch, decreases the gain error of DTH, reduces the output common-mode (CM) deviation of DTH, and enhances the CM rejection of DTH. Based on SMIC 0.18μm CMOS technology and 1.8V power supply, over the input range, results from spectre shows dummy DDPAs of DTH operate effectively, the offset of output CM voltage of DTH decrease to less than 2mV, gain error decrease to less than 1%, the gain of middle novel pre-amplifier and boundary novel pre-amplifier are both 2.5, bandwidths are all above 1.9GHZ, while power dissipation of each DDPA is 3.22mW. The high CM rejection and low gain error decrease the quantification error effectively, and enhance the performance of ADC. The design meets the requirement of ADC applied to software defined radio (SDR).


2019 ◽  
Vol 28 (06) ◽  
pp. 1950095 ◽  
Author(s):  
Mahdi Rezvanyvardom ◽  
Amin Mirzaei

This paper investigates a time-to-digital converter (TDC) that employs interpolation and time stretching techniques for digitizing the time interval between the rising edges of two input signals as well as increasing the resolution. In the proposed TDC, interpolation is performed based on a dual-slope conversion. The proposed converter eliminates the comparator offset voltage error and the comparator parasitic capacitor error compared with the TDCs that have been proposed previously. The features of the converter consist of the high accuracy and high resolution due to elimination of errors and usage of the analog interpolation structure. Moreover, it does not use gated delay lines in its structure and has the advantage of low sensitivity to the temperature, power supply and process (PVT) variations. For validation, the proposed TDC is designed in TSMC 0.18[Formula: see text][Formula: see text]m CMOS technology and simulated by Hspice simulator. The comparison between the theoretical and simulation results confirms the benefits of the proposed TDC operation. The results prove that it can be employed for high speed and resolution applications.


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