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Field Programmable Analog & Gallium Arsenide

“Gallium Arsenide (GaAs) is the silicon of the future. Is and always will be.” That was the humorous perspective circulating among analog technologists in the late 1980s. In a similar vein, I can't count the number of times I've had people ask me when will the world see a field programmable analog array (FPAA) — the analog counterpart to the digital field programmable gate array (FPGA).

That is also the future of analog. And just like GaAs, it will remain always in the future for one simple reason: Analog is physical whereas digital is algorithmic. Unless someone can 3D-print an analog IC on your desk, FPAAs will never come to pass.

That's right. I used the word “never.” And yes, I know there are things like pSoCs from Cypress Semiconductor. But those products are not FPAAs. Rather they are microcontrollers with digital and some reconfigurable analog thrown in.

It isn't that people haven't tried to do an FPAA. In fact, the world is littered with the remnants of FPAA dreams gone awry and, along with them, about $1 billion in risk capital down the toilet. You would think that after nearly 30 years of trying, someone would have figured it out by now if it were possible.

A while ago I looked into the history of FPAA technology and compiled this timeline:

  • 1988 California Institute of Technology, US: programmable fabric of current mode devices
  • 1990 Pilkington Microelectronics, UK: programmable switched capacitor arrays connected around amplifiers
  • 1994 International Microelectronic Products, US (European IMP team reincarnated today as Dialog Semiconductor): EPAC electronically programmable, predefined blocks
  • 1996 Zetex Semiconductors Ltd., UK: Electronically programmable, predefined blocks
  • 1997 Faura, Spain: Programmable, predefined blocks with a huge digital core
  • 1997 Motorola, US: Bought rights to Pilkington (see above)
  • 1998 Motorola and IMP withdraw from the FPAA market
  • 1999 SIDSA, Spain: FIPSOC similar to Faura above
  • 1999 Lattice, US: ispPAC, programmable predefined blocks

It was in 1999 that EE Times contributor Stephan Ohr summed up the problem in a piece he affectionately titled “Programmable Analog-here we go again.” Ohr concluded that all of the pre-2000 techniques suffered from the idea that customers would put a $7 to $20 part in a $1.58 socket.

In 2002, Cypress Semiconductor introduced the pSoC for about $1.58. Nice try, but no FPAA. The last attempt I am familiar with was GTronix in 2002. GTronix, or more likely its investors, gave up in 2010. While Lattice's ispPAC is still around, barely, and pSoCs seem to enjoy some success in reconfigurable analog, the rest are history.

Of all the players I listed above, I feel compelled to hand out the FPAA Courage Award to the team from Pilkington. Pilkington's technology started with its roots in the UK in 1990. Motorola, in 1997, and despite my uncompensated recommendation that it pass, acquired the technology with dreams of selling FPAAs at FPGA prices.

Motorola gave up shortly thereafter, and the technology moved back to the UK under the name of a company called Anadyne Microelectronics plc. It changed its name in 2000 to the much catchier Anadigm Inc. and established an office in Silicon Valley. Twenty-three years after Pilkington's start, Anadigm still has a website, but its address on Google Maps suggests a mailbox in Arizona. So I'm not precisely sure of its status, although Reid Wender listed Anadigm as one of his company’s competitors, so who knows? Maybe someone can update me on its status so I can hand-deliver the plaque.

Look, FPAAs are a non-starter. And I don't say this as just an outside observer. My bones can also be found in the scrap heap of FPAA dreams. But if there is a viable programmable analog technology, it will be found in the form of an analog front-end IC filled with multiple data converters and mated against an FPGA. Then non-analog types can GUI an analog system very quickly without worrying about 15mV op amp offset voltages.

14 comments on “Field Programmable Analog & Gallium Arsenide

  1. DEREK.KOONCE
    May 21, 2013

    Scott,

    This is a wonderful geneology of FPAAs. Thanks for sharing. I have not heard of most of the companies listed. If someone is out there working on updating the semiconductor tree history, this would be a nice small chapter to add.

  2. Scott Elder
    May 21, 2013

    Thanks for the comment, Derek.  Let's hope others can expand the history. 

  3. bjcoppa
    May 21, 2013

    Nice overview of the history and evolution of this technology. Motorola begin breaking into pieces in the late 1990s as noted. They were once a leader in hard disk drive tech as well. The confusion over the affiliate stated in the article is no surprise as the company has sold off or spun off its facilities/operations in the Phoenix, AZ area to a large number of smaller companies and google maps etc has not always kept track.

  4. Brad Albing
    May 23, 2013

    Hmm… 3-D printing an IC at your desk – that's actually not a bad idea. Probably not practical today, but maybe soon – and then you actually could make exactly the analog IC you need, even if you only need small quantities.

  5. amrutah
    May 25, 2013

    With shrinking technology and voltage and new high-K dielectrics, the strive for low threshold devices using GaAs is not a far future, but I don't understand how the FPAA might work and get ready for future.

    The companies as you mentioned have invested a lot of money and time without much success.  What keeps them in the race for achieving the FPAA's?

    For any analog application would need different voltage (different programmble switchers and LDO), reference voltages, lots of current sources, ADC's, DAC's, comparators, analog and digital muxes for testing.  Having all these minimum modules on a single chip would be one hell of a task.  I cannot imagine the future for FPAA's…

  6. Scott Elder
    May 27, 2013

    @amrutah

    <>

    I think there are two reasons:

    (1) People don't study history.

    (2) Some people don't care about history and go forward anyway.  These people I like better than (1).  At least they understand the risks.  Society needs risk takers otherwise we go nowhere.  Who knows, maybe someone will develop a 3-d IC printer.  When I was in college I used to dream about designing a desktop fab.  Process one wafer at a time.

  7. SunitaT
    May 27, 2013

    Maybe someone can update me on its status so I can hand-deliver the plaque.

    @Scott, thanks for the post. I just visited the anadigm website, press release section. I found the link which said “Announces Price Reduction for Field Programmable Analog Array Development System”. I am not sure what are the features of that FPAA system.

  8. SunitaT
    May 27, 2013

    What keeps them in the race for achieving the FPAA's?

    @amrutah, I think one reason could be that companies want to implement FPAA because no other company was able to implement it. I am sure there are lot of advantages of FPAA which is motivating the companies to continue with their R&D program.

  9. SunitaT
    May 27, 2013

    I have not heard of most of the companies listed.

    @DEREK, true. I also haven't heard many those companies listed. I think one reason could be that major palyers understand the risk involved in investing in FPAA R&D. But its really good to know that small players have also invested heavily in R&D activities. 

  10. SunitaT
    May 27, 2013

    3-D printing an IC at your desk – that's actually not a bad idea. Probably not practical today, but maybe soon

    @Brad, I totally agree with you, 3-D printing and IC at our desk might become reality soon. But I dont think we will be able to print short channel transistors since lot of issues crop-up while manufacturing such IC's. But yes printing a transistor with long channel length might be possible.

  11. Brad Albing
    May 28, 2013

    I will finally be able to make the ICs I need to build the devices I've envisioned. Excellent. I don't need semiconductor functionality that is especially sophisticated.

  12. Brad Albing
    May 28, 2013

    >>Society needs risk takers otherwise we go nowhere. Quite so. “Those not busy being born are busy dying.”

  13. Brad Albing
    May 28, 2013

    >>I am sure there are lot of advantages of FPAA… But we need to say what the advantages are and promote them or no one will actually buy any of these parts.

    >>…which is motivating the companies to continue with their R&D program. And it remains to be seen just how motivated the companies are.

  14. Brad Albing
    May 28, 2013

    @SunitaT – you should take a look at their site and report back to let us know what you learn.

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