Pipelined adc design and enhancement techniques analog. Pipelined adcs have seen phenomenal improvements in performance over the last few years. Pipeline adc with a nonlinear gain stage and digital. Large dc gain and large capacitors are shown to be necessary to achieve high linearity in a pipelined adc. Directconversion adcs are a class of adcs that operate at very high speeds, because. Adcs by their dac structures, conversionspeed enhancement techniques. Written for both researchers and professionals, pipelined adc design and enhancement techniques provides.
Below is a simulink model for a pipelined adc including nonidealities such as offsets, matching, and noise. Bibhudatta sahoo university of illinois at urbanachampaign. Pipelined adc design and enhancement techniques by imran. Design of highperformance pipeline analogto digital. Detailed knowledge of the behavior in a system allows the adc design margin to be minimized thus saving cost and power consumption. Basic block of pipelined adc design requirements vilem kledrowetz, jiri haze dept.
As such, when designing a pipelined adc a clear understanding of the design tradeoffs, and state of the art techniques is required to implement todays high performance low. In this work three techniques to improve pipelined adc performance with respect to linearity and power consumption are presented. Pipelined adc design and enhancement techniques imran. The pipelined adc is a practical and efficient structure for moderate speed1200mss, moderate resolution 1016 bits adcs. Accuracy enhancement techniques in lowvoltage highspeed pipelined adc design public deposited. Jasbir kaur, 2saurabh kansal 1assistant professor, 2me scholar electronics vlsi design electronics and communication engineering department pec university of technology, chandigarh, india abstractthe performance of the analog to digital. This dissertation presents the design of three highperformance successiveapproximationregister sar analogtodigital converters adcs using distinct digital background calibration techniques under the framework of a generalized codedomain linear equalizer. In addition, it explores the limitations of pipelined sar adcs, which recently have demonstrated high power efficiency at conversion rates of several tens of mss and sndr 65 db.
Bicmos or bipolar processes, the mainstream of pipelined adc design has already. Design of highspeed analogtodigital converters using low. High performance sar ad converter with calibration. Design challenges and improvement techniques for sar adc. A new approach for low power adc design nicholas wood erik jonsson school of engineering and computer science the university of texas at dallas richardson, texas, 750803021 email. Introduction the goal of this project is to design a 12bit pipeline analog to digital converter adc. The motivation for designing a pipeline adc comes from the desire to characterize and test the functionality of the novel split adc architecture concept 1 using a nonalgorithmic adc. As cmos technologies improve and smaller process sizes lead to an increase in the implementation of digital signal processing, the potential for digital correction and calibration of adcs has. Accuracy enhancement techniques in lowvoltage high. Butterfield boise state university december 15, 2011 1. The second technique develops a new mdac topology which enables a pipelined adc to be designed without a frontend sampleandhold, and thus allows for. Low power design techniques for high speed pipelined adcs.
Through the aid of new techniques and concepts, the power dissipation of lowtomedium resolution adcs benefit from going to more modern cmos processes. The adc has 8 stage, that expect amplifiers the other elements are ideal. Monotonic multiswitching method for ultralowvoltage. At unfortunately by enhancement of resolution, power the front end, the. Pdf basic block of pipelined adc design requirements. A 15bit radix4 pipeline adc 6, 7 has been simulated in matlab for illustration validity of calibration method. The successive approximation adc has a very simple structure, low power, and reasonably fast. This thesis project aims at modeling and implementation of a pipelined adc with high speed and low power consumption. Improving accuracy and energy efficiency of pipeline analog. Improving accuracy and energy efficiency of pipeline. Pipeline adc block diagram university of california. In this chapter circuit level implementation and design related issued were discussed for key components in a 1.
Department of electrical and computer engineering university of toronto abstract in this work three techniques to improve pipelined adc performance with respect to linearity and power consumption are presented. The pic32 12bit highspeed successive approximation register sar analogtodigital converter adc includes the following features. Design and implementation a 8 bits pipeline analog to digital. Accuracy enhancement techniques in lowvoltage highspeed. Sensor data is lost andor adc dynamic range is not fully utilized because the spans are unequal, start at different dc voltages, or both. Trimming is one such method, but it cannot track varia. The paper describes design requirements of a basic stage called mdac multiplying digitalto. The first is a capacitor and opamp sharing technique that reduces the load on the first stage opamp by three fold.
Sampling frequency is 100 mhz and desired adc is chosen a 15bit sigmadelta. Pipelined adc design and enhancement techniques springerlink. Background calibration techniques for multistage pipelined adcs. Low power design techniques for high speed pipelined adcs public deposited. We believe in bringing together your team and ours early in the concept phase to develop the most cost effective design for fabrication and assembly. Pipeline adc with a nonlinear gain stage and digital correction. In switchedcapacitor techniques for highaccuracy filter and adc design, alternative sc techniques are proposed which allow the achievement of higher.
This research investigates the design of highspeed sar adcs to identify circuit techniques that improve their conversion speed while maintaining low energy operation. It was shown for a desired settling accuracy, mdac opamps require. The digital outputs from adc are executed in the digital signal processor dsp. A design tradeoff which exists for pipeline adcs is the choice between a larger number of bits resolved per stage hence less latency, but more design complexity, or a fewer number of bits. This paper describes a 8 bits, 20 msampless pipeline analogtodigital converter implemented in 0. Adc snr is shown to be related to capacitor area, where to achieve a high snr large capacitors are required. Study of various adcs and compare their performance and parameters 1mrs. Butterfield 1 12bit pipelined adc design project justin d. The proposed rapid calibration scheme enables significantly shorter. Modeling and implementation of a 6 bit, 50mhz pipelined adc. Because adc circuits take in an analog signal, which is continuously variable, and resolve it into one of many discrete steps, it is important to know how many of these steps there are in total. Pipelined adc analog to digital converter digital to. Many good adc architectures have been invented to satisfy different requirements in different applications.
Applications of sar adc is used widely data acquisition techniques at the sampling rates higher than. Practical considerations of adc circuits digitalanalog. Study of various adcs and compare their performance and. This paper explores these issues in detail and presents alternative design techniques for. In the proposed technique, design problems of analogue circuits are moved inside.
Circuit techniques used include a precise comparator, operational amplifier and clock management. The goal of this major qualifying project is to design and fabricate a 16bit 10mhz pipeline analog to digital converter adc using 0. Highperformance pipeline ad converter design in deepsubmicron cmos by yun chiu b. Architecture complexity is proportional to the resolution n nj throughput is significantly improved relative to algorithmic or sar digital redundancy works the same way as algorithmic interstage gain enables stage scaling to save power and area. This leads to use digital calibration technique which relaxes design. Pipelined adc design and enhancement techniques analog circuits and signal processing. Through the aid of new techniques and concepts, the power dissipation of lowto medium resolution adcs benefit from going to more modern cmos processes. In this thesis, two novel accuracy improvement techniques to overcome the accuracy limit set by analog building blocks opamps and capacitors in the context of lowvoltage and highspeed pipelined adc design are presented. Highperformance pipeline ad converter design in deep. The pipeline analogtodigital converter adc architecture is the most popular topology for video processing,telecommunications,digital imaging etc. Pipelined adc design and enhancement techniques ebook por. Pdf pipelined adc digital calibration by using polynomial.
Because adc circuits take in an analog signal, which is continuously variable, and resolve it into one of many. Modeling and implementation of a 6 bit, 50mhz pipelined. Over the last 15 years, digital performance has increased 150 times more than anal 1. Mdac design considerations capacitor matchinglinearity. Written for both researchers and professionals, pipelined. Design considerations the first step in the design is to setup the comparators and multiplexers for the 1. However, these techniques are difficult to apply on the middle resolution and middle. Design and implementation a 8 bits pipeline analog to. Finally, residue amplifier pipeline adcs offer a few advantages over typical flash adcs. In addition, it explores the limitations of pipelinedsar adcs, which recently have demonstrated high power efficiency at conversion rates of several tens of mss and sndr 65 db. Design techniques for ultrahighspeed timeinterleaved. Perhaps the most important consideration of an adc is its resolution. Electrical engineering and computer sciences in the graduate division of the university of california, berkeley. Title digital gain error correction technique for 8bit pipeline adc forfattare author khalid javeed sammanfattning abstract an analogtodigital converter adc is a link between the analog and digital domains and plays a vital role in modern mixed signal processing systems.
Pipelined adc enhancement techniques computer engineering. Adc1 control register 1 this register controls the basic operation of the adc module, including behavior in sleep and idle modes, and data formatting. Choose the right data converter for your application. The first technique enables rapid background digital correction of both dac and gain errors in the multibit first stage of an 11bit pipelined adc. Use of multibitperstage architecture and design optimization can achieve 14bit performance as demonstrated in 5, but most pipelined adcs with more than 12bit resolution will usually require some kind of linearity enhancement techniques. Although the highest performance monolithic pipelined adcs are still built in. As such, when designing a pipelined adc a clear understanding of the design tradeoffs, and state of the art techniques is required to implement todays high performance low power adcs. A low power, middleresolution 710 bit, middle speed 20mhz200mhz pipelined adc is an important block in modern applications of telecommunication, consumer electronics, and medical electronics. Pipelined adc design and key tradeoffs are discussed. Correction of nonideal amplifiers effect in pipelined adcs. Pipelined adc design a tutorial based on slides from dr. The model resolution is very flexible, and system level techniques are easily added.
Abo, design for reliability of low voltage, switchedcapacitor circuits, ucb phd thesis, 1999 d1,d0 v dac vc f vc s v i q cs c s xv i q cf c f xv i f 1. As we can see from the flash adc architecture shown in figure 1, the number of comparators and logic elements in a flash adc is on the order of 21, where n is the number of bits, we can see the number of components doubles with each additional bit. Driver circuit design of switchedcapacitor successive approximation register sar analogtodigital converters adc is critical. Sensor to adcanalog interface design introduction the sensor output voltage span seldom equals the analogtodigital converter adc input voltage span. Pipelined adc design and enhancement techniques analog circuits and signal processing ahmed, imran on. Practical considerations of adc circuits chapter digitalanalog conversion pdf version. Background calibration techniques for multistage pipelined. Pipeline adc with a nonlinear gain stage and digital correction a major qualifying project submitted to the afculty. Pdf pipelined adc design and enhancement technqiues. Lowpower highperformance sar adc design with digital.
Adc has a unique experience in solving complex problems through product and process engineering. High performance sar ad converter with calibration techniques. Our approach to product development is based on team work. Design techniques for ultrahighspeed timeinterleaved analogtodigital converters adcs by yida duan a dissertation submitted in partial satisfaction of the requirements for the degree of doctor of philosophy in engineering. Monotonic multiswitching method for ultralowvoltage energy. At unfortunately by enhancement of resolution, power the front end, the sample and. Cascade several low resolution stages to obtain high overall resolution. As cmos technologies improve and smaller process sizes lead to an increase in the implementation of digital signal processing, the potential for digital correction and calibration of adcs has emerged.
In the work included in this thesis an accurate model of a successiveapproximation adc is developed. Review of analogtodigital conversion characteristics and design. As verification of the proposed design methodology, a 10bit 40mhz pipeline analogtodigital converter prototype is developed in commercial tsmc 90nm cmos technology. Pipeline adc block diagram university of california, berkeley.
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