digitally assisted pipeline adcs theory and implementation

[...]... 7-6 Digitally Assisted Pipeline ADCs Published flash ADC performance vs technology Basic amplifier model Noise limited circuit energy versus speed and technology Ratio slewing/linear settling time vs sampling speed Noise limited circuit energy with slewing included Published 10-bit pipelined ADC performance vs technology Typical 10-bit pipelined ADC power distribution Analog circuit challenges and. .. circuit power efficiency, and provides a correction to previous, pessimistic analyses Chapter 4 aims to identify opportunities for improving the power efficiency in ADCs The cost for precise and linear analog signal amplification in terms of power efficiency is evaluated, and serves as the main motivation for the modified, open loop pipelined ADCs discussed in chapter 5 Chapters 6 and 7 describe the proposed... linear and nonlinear pipeline stage nonidealities The two main elements of the developed scheme are a redundancy-based digital correction mechanism and a statistics based background calibration technique Chapter 8 details the implementation of a 12-bit 75 MS/s pipelined ADC [5] that was used to evaluate the proposed concepts Detailed measurement results confirming the feasibility of the digitally assisted. .. block diagram of the digitally assisted ADC A digital post-processor takes the raw, imprecise conversion result and performs the task of identifying and compensating analog domain nonidealities, including mismatch errors and amplifier nonlinearity In the described converter, the system identification process is based on the INTRODUCTION 3 evaluation of the raw code signal statistics, and “blind” in the... during normal ADC operation to track variations in operating conditions such as temperature and supply voltage Digital correction and calibration of analog domain non-idealities is not new Especially in pipelined ADCs, digital correction [3] and calibration [4] have been used extensively to overcome offset and unit element mismatch errors However, the characteristic feature of the approach demonstrated... 97 102 103 103 104 106 107 108 109 110 112 113 113 114 115 115 116 117 117 118 119 xiv 9-14 9-15 9-16 A-1 A-2 B-1 C-1 Digitally Assisted Pipeline ADCs Stage 1 power breakdown FOM2 performance of the prototype Estimated post-processor area for linear and cubic calibration Open-loop pipeline stage Equivalent stage model Simulated estimator variance for Gaussian input LMS loop block diagram 119 120 122... high speed Nyquist conversion at medium resolutions of 8-14 bits and conversion speeds ranging from 1-200 Mega-Samples per second (MS/s) Typical applications include radio receivers and base stations, digital imaging and video, ultra-sound, radar and sonar systems In this book, the pipelined ADC topology is used as a vehicle to derive and demonstrate an alternative approach to conventional quantizers... speed and power efficiency of analog-to-digital converters In particular, we explore the opportunity to overcome analog circuit limitations by incorporating digital domain algorithms into the conversion process The proposed digitally assisted converter makes extensive use of the dense, low cost and low power DSP circuitry available in modern integrated circuit technology In recent years, the pipelined... being impeded by its limitations Among the key building blocks in pipelined ADCs are the residue amplifiers that interface successive converter stages Especially in the converter front-end, these gain elements have to meet very stringent speed, noise and linearity specifications and therefore tend to set the overall power dissipation and attainable speed The key feature of this research is a DSP driven... include an 8-bit, 20-GSample/s ADC [13], and 5-GHz transceiver chips for wireless local area networks [14-16] In the following survey, we will examine the rate of performance growth in ADCs To capture and compare performance of ADCs, we use a set of commonly used figures of merit The following section briefly discusses these quantities with respect to their origin and limitations 3.1 ADC Figure of Merit . h1" alt="" DIGITALLY ASSISTED PIPELINE ADCs This page intentionally left blank Digitally Assisted Pipeline ADCs Theory and Implementation by Boris Murmann Standford University and Bernhard. 45 viii Digitally Assisted Pipeline ADCs 4. Two-Stage Feedback Amplifier vs. Open-Loop Gain Stage 46 5. Discussion 52 5. OPEN-LOOP PIPELINED ADCS 53 1. A Brief Review of Pipelined ADCs 53. factors A VT , and A E with technology). 30 3-12. Estimated flash ADC energy versus feature size (from speed trajectory in Figure 3-11). 31 xii Digitally Assisted Pipeline ADCs 3-13. Published