The World Leader in High Performance Signal Processing Solutions Farnell & Analog Devices partner to host a webinar on ‘Converter Simulation – Beyond the Evaluation Board’ Analog Devices’ Approach to Behavioral Modeling By: Tom MacLeod

Outline  Modeling Overview Who am I? What is Converter Simulation? Why Model at All? How Does One Model Behavior? How Does One Model Converter Behavior? Modeling Converter Behavior Can behavioral modeling be any good? What can converter modeling do for me? Does Analog Devices currently have a converter modeling tool? What is the Future for Behavioral Modeling?  Review  Q&A 2

Who am I?  My name is Tom MacLeod  Applications/Software Engineer for the Converter System Applications group Developer of ADIsimADC™ Developer of Tools/Scripts for the lab Traditional Applications for High Speed ADCs  Been with ADI for years  Graduated from North Carolina State University

What is Converter Simulation?  It is a “top down” or “black box” approach to modeling a converter (inherently a mixed signal device)  It models the “what” as opposed to the “how” Models the transfer function rather than multi-stage pipeline Models harmonic distortion rather than transistor imbalance within a current mirror of an input buffer  It implements a unique strategy, modeling characteristics of interest (proxies) without needing to know the circuit level implementation

What is Converter Simulation? (cont.)  The concept of modeling converter proxies generalizes to a modeling philosophy known as “behavioral modeling”  Behavioral Modeling – the ability to model apparent behavior of a process or entity without simulating the complex internal subsystems which yield such behavior Example: IBIS (Input Output Buffer Information Specification ) Models  IBIS is a method of providing information about the input/output buffers of an integrated circuit to the outside world. It is an EIA (Electronic Industries Alliance) standard. The idea of IBIS is to provide the behavioral aspects of a circuit without providing the actual circuit information to the user. – Wikipedia  Models: Current vs. Voltage Voltage vs. Time

What is Converter Simulation? (cont.)  What behavioral modeling is not Not SPICE (Simulation Program with Integrated Circuit Emphasis)  General-purpose analog electric circuit simulator Not a database Not Evaluation Software

Why Model at All?  Simulation is becoming heavily used in system design and initial characterization to reduce risk and cost  Modeling communicates information about new products more quickly and comprehensively than traditional means of product introduction  Modeling communicates information about our current portfolio more efficiently and intuitively to the “young kids with their iPods and videogames”

Why Model at All? (cont.)  Benefits of Behavioral Modeling Reduces the technical complexity of the modeling tool  Decreases simulation time  Increases productivity and user satisfaction Abstracts implementation and consequently intellectual property Leverages reuse of modeling tool for similar products  Can parameterize proxies thus providing a framework to support similar products Simplifies model creation process  Important when creating and maintaining hundreds of products

How Does One Model Behavior?  Answer: Math Models!  Example – Gaussian Distribution  Example – Population Growth

Modeling Converter Behavior  A model should faithfully reproduce converter proxies (both static and dynamic) such as: Offset Gain Quantization Sample Rate Dependencies Input Bandwidth Jitter Sensitivity Latency AC and DC Linearity 10

Modeling Converter Behavior (cont.)  It should be flexible enough to support different architectures Pipeline Delta-Sigma SAR  Support many “bolt-on” features Numerically Controlled Oscillators Digital Filters Noise Shapers Analog Filters Low Noise Amplifiers Variable Gain Amplifiers

Modeling Converter Behavior (cont.)  A model should be contained within a library so that it can be called from multiple applications Dynamic Linked Library (DLL)

Can behavioral modeling be any good? Model Physical Part = AD6645 Model

Can behavioral modeling be any good? (cont.) AD9271 (Octal LNA/VGA/AAF/ADC) Model Physical

What can converter modeling do for me?  Live datasheet Find typical performance not explicitly listed on the static datasheet Part = AD9229, Ain = 49.3 MHz SNR = 68 dB, 2 nd = -82.8, 3 rd = -80.3

What can converter modeling do for me? (cont.)  Didactic Consider impact on performance from jitter (AN-501) AD9246, Ain = 2.3 MHz, fs = 125 MSPS Calculate “composite DNL” 16

What can converter modeling do for me? (cont.)  AD9246, Ain = MHz, fs = 125 MSPS 13 fsec difference 17

What can converter modeling do for me? (cont.)  Didactic Consider effects of adding band limited dither 18 Without DitherWith Dither

What can converter modeling do for me? (cont.)  Product selection Find the product that meets your requirements under your conditions  Welcome to the online ADIsimADC Design Tool Click here

What can converter modeling do for me? (cont.) Input your requirements (SNR > 78 dB SFDR <= -85 dBc) Click here Input your conditions

What can converter modeling do for me? (cont.) Models that met my requirements

What can converter modeling do for me? (cont.) It worked! SNR = 78 dB SFDR = -93 dBc What’s 100k volume pricing?

What can converter modeling do for me? (cont.)  Product Evaluation A subset of products (those ending in.PMF) support a register map interface Example – AD

What can converter modeling do for me? (cont.)  Tuning word changed from 28 to 0 Same as real device 24

What can converter modeling do for me? (cont.)  System Level Simulation Simulate the effects a particular ADC will have on your system LTE Uplink (5 MHz) waveform AD6655 (14-bit IF receiver) SNR = 65.7 dB

Does Analog Devices currently have a converter modeling tool?  Yes - ADIsimADC 26

Where can I buy ADIsimADC?  You can’t buy it! It’s free! Visit:  As part of ADI’s “whole product initiative” There is no cost to use this tool; use it in whatever environment you prefer + =

Where can I buy ADIsimADC? (cont.)  We package it with VisualAnalog (also free) Just install VisualAnalog, run it, browse for your favorite ADC, select it and start modeling! Also available as an online design tool

What products are currently supported? AD6645_105AD9214_105_1VAD9218_80_1VAD9230_210AD9238_20AD9246_105AD9255_125AD9268_80AD9445_105_3p2VAD9600AD9629_40AD80141AD9230AD9252AD9287AD9609 AD6645_80AD9214_65_2VAD9219_40AD9230_250AD9238_40AD9246_125AD9255_80AD9271AD9445_125_2VAD9601AD9629_65AD9204AD9231AD9254AD9289AD9626 AD6655AD9214_80_1VAD9219_65AD9231_20AD9238_65AD9248_20AD9258_105AD9272AD9445_125_3p2VAD9609_20AD9629_80AD9211AD9233AD9255AD9430AD AD6657AD9215_105AD9222_40AD9231_40AD9239_170AD9248_40AD9258_125AD9273AD9446_100_2VAD9609_40AD9640AD9214AD9236AD9258AD9433AD9627 AD80141AD9215_65AD9222_50AD9231_65AD9239_210AD9248_65AD9258_80AD9287AD9446_100_3p2VAD9609_65AD9644_80AD9215AD9237AD9259AD9444AD9629 AD9204_20AD9215_80AD9222_65AD9231_80AD9239_250AD9251_20AD9259AD9289AD9446_80_2VAD9609_80AD9649_20AD9216AD9238AD9262AD9445AD9640 AD9204_40AD9216_105AD9226_2VAD9233_105AD9244_40AD9251_40AD9262AD9430_170_LVDSAD9446_80_3p2VAD9626_170AD9649_40AD9218AD9239AD9265AD9446AD9644 AD9204_65AD9216_65AD9228_40AD9233_125AD9244_65AD9251_65AD9265_105AD9430_210_LVDSAD9460_105_3p4VAD9626_210AD9649_65AD9219AD9244AD9268AD9460AD9649 AD9204_80AD9216_80AD9228_65AD9236AD9245_20AD9251_80AD9265_125AD9433_105AD9460_80_3p4VAD9626_250AD9649_80AD9222AD9245AD9269AD9461 AD9211_200AD9218_105_1VAD9229_50AD9237_20AD9245_40AD9252AD9265_80AD9433_125AD9461_125_3p4VAD AD6645AD9226AD9246AD9271AD9480 AD9211_250AD9218_40_1VAD9229_65AD9237_40AD9245_65AD9254AD9268_105AD9444AD9461_130_3p4VAD9627AD6655AD9228AD9248AD9272AD9600 AD9211_300AD9218_65_2VAD9230_170AD9237_65AD9245_80AD9255_105AD9268_125AD9445_105_2VAD9480AD9629_20AD6657AD9229AD9251AD9273AD9601 All high speed (>20 MSPS) ADCs for the last 5 years. 188 models so far…

What is the Future for ADIsimADC?  Support for high-precision ADCs <20 MSPS 16-bit to 24-bit delta sigmas and PULSARs Depends on proxies we identify are important  Support for more accurate models Better integration with SPI control software User defined phase noise profiles Arbitrarily oversampled inputs Statistical distribution of products (Monte Carlo) Temperature sensitivities Open to suggestions!

What is the Future of Behavioral Modeling?  Support for precision ADCs  Support for DACs  Support for clocks  Support for amplifiers  Support for modulators/demodulators  Need feedback!

Review  Behavioral modeling has been shown to be a viable and effective technology Purposes  Live datasheet  Didactic  Product selection  Product evaluation  System level simulation  Analog Devices freely offers ADIsimADC, a converter behavioral modeling tool as part of its “whole product” initiative We want this tool to be part of a dialog between you and us  Give us feedback  Provide suggestions  Try and break it  Analog Devices is committed to maturing this technology 32

Outline  Modeling Overview Who am I? What is Converter Simulation? Why Model at All? How Does One Model Behavior? How Does One Model Converter Behavior? Modeling Converter Behavior Can behavioral modeling be any good? What can converter modeling do for me? Does Analog Devices currently have a converter modeling tool? What is the Future for Behavioral Modeling?  Review  Q&A 33

The World Leader in High Performance Signal Processing Solutions Thank You!

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