EECS 247 Analog Digital Interface Integrated Circuits 2006 Instructor Haideh Khorramabadi UC Berkeley Department of Electrical Engineering and Computer Sciences Lecture 1 Introduction EECS 247 Lecture 1 Introduction 2006 H K Page 1 Instructor s Technical Background Ph D EECS department UC Berkeley 1985 advisor Prof P R Gray Thesis topic Continuous time CMOS high frequency filters Industrial background 11 years at ATT Bell Laboratories N J in the R D area as a circuit designer Circuits for wireline communications CODECs ISDN and DSL including ADCs nyquist rate over sampled DACs filters VCOs Circuits intended for wireless applications Fiber optics circuits 3 years at Philips Semiconductors Sunnyvale CA Managed a group in the RF IC department developed ICs for CDMA analog cell phones 3 years Broadcom Corp Director of Analog RF ICs in San Jose CA Projects Gigabit Ethernet TV tuners and DSL circuitry Currently consultant for IC design Teaching experience Has taught co taught EE247 UCB since 2003 Instructor for short courses offered by MEAD Electronics Adjunct Prof Rutgers Univ N J Taught a graduate level IC course EECS 247 Lecture 1 Introduction 2006 H K Page 2 Administrative Course web page http inst eecs berkeley edu EE247 Course notes will be uploaded on the course website prior to each class Homeworks due dates are posted on the course website Please visit course website often for announcements Lectures are webcast mainly for the benefit of students UCSC http webcast berkeley edu courses Please try to attend the classes live to benefit from direct interactions Make sure you use the provided microphones when asking questions or commenting in class EECS 247 Lecture 1 Introduction 2006 H K Page 3 Office Hours Grading Office hours Tues Thurs 3 30 4 30pm 463 Cory Hall unless otherwise announced in the class Extra office hours by appointment You can also discuss issues via email haidehk eecs berkeley edu Course grading Homework project 50 Midterm 20 tentative date Oct 24 Final 30 Dec 18 EECS 247 Lecture 1 Introduction 2006 H K Page 4 Analog Digital Interface Circuitry Analog Output Analog Input Analog World Analog Digital Interface 001 110 010 Digital Processor 1001 1010 0010 Digital Analog Interface Naturally occurring signals are analog To process signals in the digital domain Need Analog Digital Digital Analog interface circuitry Question Why not process the signal with analog circuits only thus eliminate need for A D D A EECS 247 Lecture 1 Introduction 2006 H K Page 5 MOSFET Maximum ft Evolution versus Time ft 100GHz 0 1u 0 18u 0 13u 0 35u 0 25u 0 065u 0 6u 0 8u 10GHz 1u 1 5u 2u 1GHz 3u 6u 75 Year 80 85 90 95 00 05 For MOS VGS Vth 0 5V Ref Paul R Gray UCB EE290 course 95 International Technology Roadmap for Semiconductors EECS 247 Lecture 1 Introduction http public itrs net 2006 H K Page 6 CMOS Device Evolution Progress from 1975 to 2005 Feature sizes Cut off frequency ft Minimum size device area X1 90 X300 1 L2 Number of interconnect layers X6 EECS 247 Lecture 1 Introduction 2006 H K Page 7 Impact of CMOS Scaling on Digital Signal Processing Direct beneficiary of VLSI technology down scaling Not sensitive to analog noise has to deal with 0 1 signal levels only Si Area function reduced drastically due to Shrinking of feature sizes Multi metal levels for interconnections currently 6 metal level v s only 1 in the 1970s Enhanced functionality flexibility Amenable to automated design test Arbitrary precision Provides inexpensive storage capability EECS 247 Lecture 1 Introduction 2006 H K Page 8 Analog Signal Processing Characteristics Sensitive to analog noise Has not fully benefited from technology down scaling Supply voltages scale down accordingly Reduced voltage swings more challenging analog design Reduced voltage swings requires lowering of the circuit noise to keep a constant dynamic range Higher power dissipation and chip area Not amenable to automated design Extra precision comes at a high price Availability of inexpensive digital capabilities on chip enables automatic adjustments to compensate for analog circuit impairments Rapid progress in DSP has imposed higher demands on analog digital interface circuitry Plenty of room for innovations EECS 247 Lecture 1 Introduction 2006 H K Page 9 Cost Function Comparison DSP Analog Digital circuitry Fully benefited from CMOS device scaling Cost function decreases by 29 each year Cost function X1 30 in 10 years Analog circuitry Not fully benefited from CMOS scaling Device scaling mandates drop in supply voltages threaten analog feasibility Cost function for analog ckt almost constant or increase Rapid shift of functions from processing in analog domain to digital hence increased need for A D D A interface circuitry Ref International Technology Roadmap for Semiconductors EECS 247 Lecture 1 Introduction http public itrs net 2006 H K Page 10 Digitally Assisted Analog Circuitry Analog design has indeed benefited from the availability of inexpensive onchip digital capabilities Examples Compensating calibrating ADC DAC inaccuracies Automatic frequency tuning of filters VCOs Offset compensation EECS 247 Lecture 1 Introduction 2006 H K Page 11 Example Digital Audio Goal Lossless archival and transmission of audio signals Circuit functions Preprocessing Amplification Anti alias filtering Analog Input Analog Preprocessing A D Conversion A D Conversion Resolution 16Bits Sig bandwidth 41kHz DSP Storage Processing e g recognition D A Conversion Postprocessing Smoothing filter Variable gain amplification EECS 247 Lecture 1 Introduction DSP D A Conversion Analog Postprocessing Analog Output 2006 H K Page 12 Example Dual Mode CDMA IS95 Analog Cellular Phone RF Baseband EECS 247 Lecture 1 Introduction 2006 H K Page 13 Example Typical Dual Mode Cell Phone Contains in integrated form 4 RX filters 3 TX filters 4 RX ADCs 2 TX DACs 3 Auxiliary ADCs 8 Auxiliary DACs Dual Standard I Q Audio Tx Rx power control Battery charge control display Total Filters 8 ADCs 7 DACs 12 EECS 247 Lecture 1 Introduction 2006 H K Page 14 Areas Utilizing Analog Digital Interface Circuitry Communications Wireline communications Telephone related DSL ISDN CODEC Television circuitry Cable modems TV tuners Ethernet Gigabit 10 100BaseT Wireless Cellular telephone CDMA Analog GSM Wireless LAN Blue tooth 802 11a b g Radio analog digital Television Personal Data Assistants Computing Control Storage media disk drives digital tape Imagers displays EECS 247 Lecture 1 Introduction 2006 H K
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