IS ANALOG CIRCUIT DESIGN DEAD

1
??? ???? ?????? ??????

• ?????? ????? ? ???? ???? ? ??????

2
IN THE DIGITAL-ORIENTED ERA, DO WE REALLY NEED
ANALOG CIRCUIT DESIGN?

• Muhammad Taher Abuelmaatti
• King Fahd University of Petroleum and Minerals
• Box 203 Dhahran 31261 Saudi Arabia
• mtaher_at_kfupm.edu.sa

3
WHAT IS SAID?

• Analog design is old fashion and out of date.
• Analog design is a kind of classic art in a
  rapidly changing world of electronics.
• The powerful electronic revolution is toward DSP
  rather than ASP.
• It is not wise to select analog design as a
  career.
• It is not wise to select analog design courses.
• Analog designers are not considered the heroes of
  the modern internet and HDTV technology.
• Analog design is used only in high voltage area.
• The world has gone digital and analog is old.

4
Examples Digital Camera

• Analog chips translate wavelengths and
  intensities into digital code.
• To check the image, the camera retranslate the
  digital code into a visual display.

5
Examples Portable Receiver Design
Custom Analog IC
Custom Digital IC
RF Filter
Analog Front-End
A/D Converter
Digital Baseband Processing

• A mostly digital receiver architecture
• Go digital at the earliest possible stage

6
Receiver Block Diagram

7
Analog RF Design
8
(No Transcript)
9
(No Transcript)
10
(No Transcript)
11
Transceivers
12
Basic Analog Building Blocks

• 1. Amplifiers (Power Amplifiers, Voltage
  Amplifiers AF, RF, VF )
• 2. Oscillators (sinusoidal and others)
• 3. Filters
• 4. Clocks
• 5. Analog-to-Digital and Digital-to-Analog
  Converters.
• 6. Modulators (FSK, PSK, ASK, Amplitude, Phase,
  Frequency Modulation)
• 7. Demodulators
• 8. Mixers
• 9. Phase Locked Loops
• 10. Multiplexers.
• 11. Duplexers

13
The Reality

• No human experiences reality as a pattern of 1s
  and 0s.
• The natural world is analog with endlessly
  variable waves of sound and light, temperature
  and pressure fluctuations, and shifting magnetic
  fields.
• Digital revolution drives a strong demand for
  advances in analog electronics.

14
ADVANTAGES OF DIGITAL CIRCUIT DESIGN

• Robustness two signal levels.
• Simple and cheap to design well developed CAD
  software.
• Very suitable for integration.
• Offers high precision.
• Programmability can be easily obtained.
• Easy to design at system level.
• Have a cycle/success ratio near unity.

15
ADVANTAGES OF ANALOG CIRCUIT DESIGN

• Efficient use of bandwidth.
• Simple no S/H, A/D and D/A.
• Lower power consumption uses fewer transistors.
• Low cost smaller silicon chips.
• Power efficient.
• Uses physical properties of transistors.

16
WHEN AND WHERE ANALOG CIRCUIT DESIGN IS NEEDED?

• To interface a DSP with the input sensors.
• To interface a DSP with the output actuators.
• In low precision systems analog neural networks.
• In high frequency systems.
• In enhancing the performance of digital circuits.
  On the average, there is probably 15 analog chips
  needed for every digital processor.

17
ANALOG ENHANCED DIGITAL PERFORMANCE

• Enhancing the performance of the hard disk drive
  by reshaping distorted high speed digital pulses.
  
• High speed digital circuits are partly analog!
  Relatively large rise and fall times.
• In memory chips and microprocessor chips entire
  analog blocks such as amplifiers and PLLs are
  used.
• High frequency clocks.

18
Digital Enhanced Analog Performance

• Analog microchip performance can be improved by
  integrating them with digital monitoring and
  control circuits.
• The line between pure digital and pure analog
  chips is rapidly blurring, with both
  incorporating a little bit of the other.
• That is Mixed Mode. Experts with feet in both
  realm are especially valuable.

19
MIXED ANALOG AND DIGITAL CIRCUITS

• Advantages
• 1. Reduced system size.
• 2. Reduced power dissipation.
• 3. Increased speed of operation.
• 4. Increased design flexibility.
• 5. Increased reliability.
• 6. Reduced system cost.

20
CURRENT RESEARCH IN MAD CIRCUITS

• A combination of high dynamic range, high
• speed and acceptable low power dissipation
• is a challenge for MAD circuits.
• Analog neural networks.
• Field programmable analog arrays.
• Radio frequency circuits.
• Analog image processing.
• Disk drive electronics.
• Fuzzy logic.
• Chaotic circuits and systems.

21
WHERE MAD CIRCUITS ARE USED?

• Almost in every broad application where chips are
  used. Examples include
• Telecommunications transmission, reception,
  switching
• Consumer electronics audio, video,
• Computers and related equipment disk drives, LAN
  transmitters and receivers,..
• Automotive systems engine control, safety
  equipment,
• Biomedical instrumentation hearing aids, cardiac
  pacemakers,
• Robotics interfaces to sensors and actuators.

22
FUTURE OF ANALOG

• The world around us is essentially analog.
• Our senses are organized for communicating with
  this world.
• Analog circuit design is indispensable and
  irreplacable.
• The future of analog circuit design is very
  dynamic and holds many opportunities.
• It takes six to nine months for a college
  graduate to be productive in digital engineering.
• It takes a Ph.D. holder four years to be
  productive in the analog area.

23
How to Enhance the Image of Analog Circuit Design

• The lack of interest in analog circuit design
  could be explained by
• Inadequate teaching of the subject. Only teachers
  with proven expertise in the area can teach
  Electronic Circuits courses.
• Extensive mathematical manipulations and/or use
  of the black box approach. This should be
  minimized and emphasis should be on the physical
  meaning of the equations.
• The lack of understanding of circuits at the
  voltage and current levels.
• Extensive use of simulation and software
  packages. More emphasis on experimental work is
  needed. Simulation is not a bad thing, but
  engineering students must feel the real world.
• Wrong advises and the advertising media.

24
CONCLUSION

• Analog circuit design is here to stay. Imagine
  the effect on the digital world of a complete
  embargo of data converters and signal-conditioning
  components by the small analog nation.
• Analog designers need not leave town.

25
?????? ??? ?? ????????

• ???? ????