Field Programmable Analog Arrays (FPAAs)

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Field Programmable Analog Arrays (FPAAs)

• Anthony Chan

ECE1352F Presentation
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Agenda

• Why Use Programmable Analog
• Switched Capacitors Current Tech
• Pulse Based Current Research
• Future of FPAAs
• Conclusions

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Why Programmable Analog?

• Faster Prototyping
• Faster Time-to-Market
• Shorter Design Cycles
• Design integration
• Improved component matching

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Structure
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Routing Architecture
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CAB Implementation

• Continuous Time vs. Discrete Time
• Discrete Time
• Switched Capacitor Design (Current)
• Pulse Based Design (Under Research)

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Switched Capacitor Based Design
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Benefits of SC Design

• Design of SC circuits quite mature
• Switches already present in FPAA
• Allows for better accuracy than RC
• 0.05 - 0.2 vs. 10 - 30

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Performance of SC Design

• Currently limited to 1MHz
• Versatile design possibilities

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Problems with SC Design

• Limitations on switching frequency
• Require non-overlapping clocks
• Voltage used to represent signal
• Signal still susceptible to noise
• Increased mixed signal noise

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Pulse Based Design

• Uses time to represent transmitted signal in the
  form of PWM
• Uses of digital signals levels
• Noise immunity
• Relatively new area of research
• Limited functionality
• Complete design not yet available

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Pulse Signals
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Pulse Based Integrator
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Pulse Based Performance
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Performance Comparison
Voltage Domain
Pulse Based
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Future of FPAAs

• SC designs will dominate commercially
• Improvements must be acheived
• FPAAs may lead to FPMAs
• Natural evolution of mixed-signal design
• Question of viability must be answered
• FPAAs vs. FPGA comparison
• 8MHz vs. 1Gbps

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Conclusions

• Programmable Analog has potential
• SC Designs currently quite functional
• Pulse designs could offer improvement
• Requires additional development
• FPAA vs. FPGA needs better analysis

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References

• 1. D. R. DMello, P. G. Gulak, Design
  Approaches to Field-Programmable Analog
  Integrated Circuits, Analog Integrated Circutis
  and Signal Processing, Vol 17, No. 1-2, pg 7-35,
  September 1998
• 2. H. Kutuk, S. M. Kang, A Switched Capacitor
  Approach to Field-Programmable Analog Array
  Design, Analog Integrated Circutis and Signal
  Processing, Vol 17, No. 1-2, pg 51-65, September
  1998
• 3. A. Bratt, I. Macbeth, DPAD-2 A Field
  Programmable Analog Array, Analog Integrated
  Circutis and Signal Processing, Vol 17, No. 1-2,
  pg 67-89, September 1998
• 4. A. Hamilton, K. Papathanasiou,
  Reconfigurable Analogue Systems The
  Pulse-Based Approach, IEE Proceedings-Computers
  and Digital Techniques, Vol 147, No. 3, pg
  203-207, May 2000
• 5. A. Hamilton, K. Papathanasiou, T. Brandtner,
  Palmo Pulse-Based Signal Processing for
  Programmable Analog VLSI, IEEE Transactions on
  Circutis and Systems II Analog and Digital
  Signal Processing, Vol 49, No. 6, pg 379-387,
  June 2002
• 6. Anadigm Website www.anadigm.com