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Where Is Analog Integration Going?

Since the birth of monolithic integrated circuit (IC) technology, analog circuit designers have looked for a quick path to new precision, compact and low cost system designs. This approach would integrate many of the standard IC functions into a new highly integrated semi-custom monolithic chip. The cost of a full custom chip was too expensive in those early days.

The 1960s
The first baby steps in the early 1960s was “discretionary wiring” on bipolar “master dice breadboards”[1] using gold ball wire bonds. These were intended as prototype devices.

Figure 1

Master Dice Bread Board

Master Dice Bread Board

Figure 2

Schematic of the available devices on the chip

Schematic of the available devices on the chip

Figure 1 shows a chip without the wire bond interconnect and Figure 2 shows the schematic of the “breadboard chip” components. Figure 3 shows a “breadboard chip” with a rat's nest of wire bonds. If breadboarding was successful, the chip would be metalized for production.

Figure 3

The chip configured as a prototype IF amplifier

The chip configured as a prototype IF amplifier

As the analog chips became more complicated, this approach was later replaced with the “master slice” process using one or two metal layers to interconnect the transistors, resistors, and capacitors as a semi-custom design (see Figure 4). Interdesign/Ferranti/Zetex (now Diodes Inc.) popularized the “Mono-Chip.” Many other semiconductor companies had similar semi-custom bipolar analog arrays.

The 1970s
Hybrid circuits using discrete transistors, thick and thin film resistors, and ceramic capacitors on a ceramic substrate with interconnecting gold patterns were a precursor to monolithics. Later on hybrids started to integrate monolithic chips (see Figure 5) and many standard products such as analog to digital converters were developed and widely used. Analog CMOS started to become mainstream as RCA Solid State and Intersil began offering all CMOS op-amps and other analog devices.

Figure 5

Thick Film Hybrid[2] Click here to see a larger image.

Thick Film Hybrid[2]
Click here to see a larger image.

Next, the 1980s – 1990s.

The 1980s – 1990s
When FPGAs first came out in the mid-1980s, we all wished that someone could invent something similar for analog design. The difficulties and complexities of analog design are not for the faint of heart. Thermal effects, parasitic components, critical electrical routing, cross talk, substrate currents, voltage breakdowns, and leakage currents are just a few of the critical issues the design engineer must deal with. FPAAs started to appear as shown in the time line in Figure 6.

Figure 6

Timeline marking important milestones in the field of FPAAs & FPMSAs (Field Programmable Mixed Signal Arrays) [3] Click here to see a larger image.

Timeline marking important milestones in the field of FPAAs & FPMSAs (Field Programmable Mixed Signal Arrays) [3]
Click here to see a larger image.

The 21St Century

Later on, multi-chip modules (MCMs[4] ) were developed to increase levels of analog integration and performance. An Agilent proprietary oscilloscope front end MCM is shown in Figure 7.

Circa 2013 Today, the newest packaging trend is System in Package (SiP) versus System on Chip (SoC); see Figure 8.

Figure 8

SoC vs. SIP design tradeoffs (Source:Toshiba)

SoC vs. SIP design tradeoffs
(Source:Toshiba)

What is System in Package? “System-in-Package (SiP) is more than an IC package containing multiple die. SiP products are fully functional systems or sub-systems in an IC package format. SiP may contain one or more IC chips (wire bonded or flip chip) plus other components that are traditionally found on the system mother board.”[5] . Thus, analog and digital components, passives, MEMs or RF components are combined to provide a sub-system or system function in a single IC package.

What is System on Chip (SoC)? “A system on a chip or system on chip… is an integrated circuit (IC) that integrates all components of a computer or other electronic system into a single chip. It may contain digital, analog, mixed-signal, and often RF functions — all on a single chip substrate.”[6]

A new approach from Triad Semiconductor that is focused on developing configurable analog and digital technology for the mixed signal ASIC market may be a step in the right direction. It's not a true FPAA but very close. See Related posts , below, for more details on this emerging technology.

Summary
Analog circuit designers are still waiting for FPAAs as the “Holy Grail” to have a quick path to new semi-custom monolithic designs. FPAAs have been around since the mid-1980s and have never broken into mainstream numbers on anyone's product forecast. As pointed out right here in Planet Analog by Scott Elder (Field Programmable Analog & Gallium Arsenide), “FPAAs are a non-starter.” Meanwhile, digital FPGAs are projected to be over a $3.5 billion market this year.

There are only two known mainstream FPAA suppliers remaining, Anadigm and Cypress with their PSoC. If you know of any others, please post their names in the comments section, below.

This week Cypress introduced a new development kit (CY8CKIT-033A) which looks very useful and very promising. See Figure 9.

Figure 9

CY8CKIT-033A PSoC 3 MFi Digital Audio Development Kit

CY8CKIT-033A PSoC 3 MFi Digital Audio Development Kit

Also available from Servenger using the Anadigm programmable chip is the “Programmable Analog Module (PAM) which is a multi-featured, tested and dependable solution that makes the functionality of the FPAA immediately usable, right out of the box. It can be used as a free-standing module or as a system component. The Servenger PAM is completely compatible with the AnadigmDesigner2 CAD design toolset”. (See Figure 10 below)

Figure 10

Servenger PAM using the Anadigm FPAA

Servenger PAM using the Anadigm FPAA

As mentioned in Brian Bailey's article Why Don’t Field Programmable Analog Arrays Work?, “I, too, would love to hear about companies that are using programmable analog systems. I'd like to make them feel welcome here. Do you know of any successful programmable analog projects [using FPAAs]?”

Whatever the case, we have evolved our analog design process from discretely connecting transistors to a systems approach. This is just a natural step as we take advantage of Moore's Law for analog integration.

References:

  1. Datasheet IC105A NM-3011, NM-3015 Norden-Division of United Aircraft. May 1965
  2. ICI (now Crane/Interpoint) Catalog circa 1984
  3. Design Approaches to Field-Programmable Analog Integrated Circuits DEAN R. D’MELLO AND P. GLENN GULAK, Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario Canada June 11, 1997, Figure 17
  4. Personal conversation with Walter Becker, WB SALES
  5. Amkor data sheet for SIP
  6. Wikpedia definition of SoC

Related posts:

26 comments on “Where Is Analog Integration Going?

  1. goafrit2
    July 29, 2013

    The most amazing thing that will happen in analog integration in the next five years will be finding a way to overcome the challenges of static noise problems as we move closer to single digit nanometer feature sizes of transistors. That is what drives this industry. It is possible we need to replace silicon or come up with another thing. Shockley did us a favor with transistor in 1940s with transistor; we may need another magic to keep this going,

  2. Tom_Terlizzi
    July 29, 2013

    goafrit2,

    You are right on. As Issac Newton declared

    “If I have seen further it is by standing on the shoulders of Giants.”.

    Technology always seems to find a away around these complex problems. I am sure we will find new ways to keep increasing integration. 

    Will it be 3-D technology or some new semiconductor material or process?

    Only time will tell that tale. The demand for higher levels of integration will drive that discovery.

    see interesting article 

    http://www.eetimes .com /document.asp?doc_id=1279934

     

    Thanks

    Tom Terlizzi

     

     

  3. Scott Elder
    July 29, 2013

    @Tom – When you figure out where all this analog stuff is heading, you should quit your job and work on wall street!  Just give us all the list of stocks to short before you start. 🙂

    Scott

  4. Tom_Terlizzi
    July 30, 2013

    Scott,

    As a “newbie” to Planet Analog-Integration Nation, I am still on a learning curve and honeymoon.

    Interesting enough on Monday July 29, I was surfacing the net for “Mixed Signal” and found an “old friend' “EXAR” (who I completely lost touch with many years ago) .

    Here's a LINK with a brief history of EXAR who started in 1971.

    http://www.fundinguniverse.com/company-histories/exar-corp-history/

     We used one of their semicustom chips on some hybrid voltage regulator products eons ago and it was a home run.

    Exar has moved to the NYSE from NASDAQ with a new slogan ….” A new direction for mixed signal”. They are doing some neat mixed signal products and Steve Taranovich just penned an article on “Exar: A new direction” on July 27, 2013

    http://www.edn.com/electronics-blogs/anablog/4418925/Exar–A-new-direction

    And here's their website where you can see them ring in the bell at the NYSE and look at their portfolio of products.

    http://www.exar.com/#

     When I figure out where all this analog stuff is heading, I will quit my day job and work on wall street!  BTY EXAR stock is up >40% this year………….

    Regards

    t2

     

  5. SunitaT
    July 31, 2013

    In 2002, a continuous-time (CT) FPAA using programmable operational trans-conductance amplifiers (OTAs) and programmable capacitor arrays was introduced by Pankiewicz et al. that performed in the 1 MHz range. The FPAA was designed in a chessboard layout with local connects and switches and the OTA tuning is attained by a programmable current mirror. This technique permits Gm tuning with 5-bit precision which is limited by the large chip area each added bit of precision adds. Therefore, this technique is not suitable for high precision tuning in an FPAA due to the chip area it would require.

  6. Netcrawl
    July 31, 2013

    @Tom good to see you here in Planetanalog, the world of analog requires all strength, its a type of technical field where experience it put to use, practice and master of the field is very important in this ground, thorough study of analog technology involves the integration of practice and theory. 

       

  7. Tom_Terlizzi
    July 31, 2013

    Thank you for updating me on the FPAA time line.

    It looks like most of the R & D for FPAA is in the programmable filter area.

    I have attached some more references on what's going on in FPAA's

    If you know of any recent one's I missed please let me know

    Thanks

    t2

    “Field Programmable Analog Arrays: A Brief History”

    By Mohammed F. Hassan | Published May 3, 2013

    http://www.vlsiegypt.com/home/?p=1125

     

     

    Programmable chips: piecing together an analog solution

    By Ron Wilson, Executive Editor – July 23, 2009

    http://www.edn.com/electronics-news/4313460/Programmable-chips-piecing-together-an-analog-solution

     

     

     

    Field programmable analog array patent

    WO 2012064551 A2   2012

    “Research on FPAAs began to appear in the academic literature in the early 1990s. Continued research and development over the past 15 to 20 years has led to greater consensus regarding FPAA architectural principles. Standard terms such as CABs (Configurable Analog Blocks) have sprung up, built from common constructions which use op amps and programmable passive components such as switched capacitor and resistor arrays. These CAB sub -components can act as integrators , summers, and attenuators which provide networks of CABs with higher- level functionality. The resultant FPAA has applications in filtering, amplification, signal conditioning, and waveform synthesis, among others.

    FPAA designs have been advancing in the last several years. An FPAA developed at Georgia Tech is an integrated device containing CABs and

    interconnects between these blocks. It is intended to impact analog signal processing in two ways. First, it performs the function of all rapid prototyping devices in reducing development time. Second, it is a platform for implementing advanced signal processing functions, usually reserved for a digital system, in analog circuits.

    Recently there have been several breakthroughs in the FPAA research. First, there is an increasing trend towards the use of high frequency, small geometry CMOS op amps as the major functional block of a CAB. Madian introduced an FPAA using CMOS Current Feedback Op Amps (CFOA) in a switch matrix specially built for high frequency, programmable filtering applications. A key drawback is low demonstrated bandwidth (order of 1 MHz). Becker created an FPAA in 130 nm CMOS using Operational Transconductance Amplifiers arranged in a hexagonal topology to achieve a routing network which avoids band-limiting switches. Here, the emphasis was on high bandwidth (order of 100 MHz) and low power consumption (< 70 mW ). The hexagonal structure allows for odd-order feedback in addition to even-order feedback. Unfortunately, this design suffers from poor scalability (single filter at a time with a 7th order maximum). It can be surmised that these new types of FPAAs will soon be used to demonstrate a wide variety of MIMO applications, particularly in advanced radar and wireless communications systems. However, wider bandwidth and sufficiently low power consumption per channelare first required.”

     

    University Research

    Professor Joachim Becker referenced in the patent above

    http://www.uni-ulm.de/en/in/institute-of-microelectronics/staff/becker.html

     

     

    Georgia Tech research on FPAA

    http://cadsp.ece.gatech.edu/fpaa.shtml

     

     

    Extensive bibliography from University of Toronto, Canada http://www.ece.ualberta.ca/~vgaudet/fpaa/bibliography.html

     

     

     

     

     

     

     

     

     

  8. Tom_Terlizzi
    July 31, 2013

    Netcrawl ,

    Thanks, It's nice to be here. Analog is an art not that digital is not.

    In digital it's a “1” or “0” so you can only be “off by 50%”.

    In the analog world, it's quite different. You can be off by >100% or total “off base”.

    Without the advances in digital technology we wouldn't be where we are today.

    That laptop you are holding would be the size of that mainframe you are hooked up to……

    Regards

    t2

     

     

  9. David Maciel Silva
    July 31, 2013

    Very good article, the trend the next you will be likely to expose the insert size and the way integrated circuits are created.

    The simulation was no longer manual and will be totally controlled by computerized applications design?

  10. Tom_Terlizzi
    August 1, 2013

    Thanks you for the kind words.

    Yes, the two trends you mentioned will speed up the design and development of new analog systems with next generation integrated circuits.

    Will there be 100's more? 

    Will we see a 1946 Dick Tracy style 2-Way Wrist Radio?

    Maybe soon…… is there anyone out there from Apple????????

  11. goafrit2
    August 2, 2013

    @Scott, the stocks are very low to be shorted. The deal is to buy now they are low.

  12. goafrit2
    August 2, 2013

    That is indeed true – there are a lot of learning and experience that will be needed in the analog integration business. Howvever, the challenge today is most college kids – really smart may not be having enough patience for that experience that comes with learning. They want to build and flip websites and mobile apps within weeks.

  13. goafrit2
    August 2, 2013

    @Tom >>
    Without the advances in digital technology we wouldn't be where we are today

    It is also true in the corollary – digital technology has also moved the world towards the holy grail in computing. There is nothing in the human brain that is close to digital. The deal is that we settled quickly on digital because it is the easy way out. The spike based protocol that the brain works might be a better way to compute even at low clock speed (you may not even need clock).

  14. goafrit2
    August 2, 2013

    >> The simulation was no longer manual and will be totally controlled by computerized applications design?

    We have that already. With Monte Carlo sims, you have got may automated sims around the design strategy. Nothing is manual these days if you truly spend time to develop some Cadence scripts.

  15. Netcrawl
    August 3, 2013

    Its true the digital technology has been notable in reshaping the nature of the analog world. But analog ICs will remain as the biggest player in the market, it will continue to represent the single largest revenue category in digital mobile devices.  

  16. Netcrawl
    August 3, 2013

    yes, it will be controlled by computerized appication design, market shift and technology forces will keep driving engineers to demand works and scalable design that can span analog and didgital domain, in the near future we will see some “great leap or advances” in design tools, these tools can interoprate seamlessly provide designers with greater flexibility and speed.

     

  17. Brad_Albing
    August 6, 2013

    @goafrit2 – yep – different mindset than that of real engineers.

  18. goafrit2
    September 16, 2013

    >> But analog ICs will remain as the biggest player in the market, it will continue to represent the single largest revenue category in digital mobile devices.

    Not sure analog is that big. Digital firms continue to do better in the stock performance.

  19. yalanand
    November 30, 2013

    @Tom, I feel the analog IC's playes major role in systems like amplifiers ,sensors ,data converters which we can not replaced entirely by digital world. So in the future I dont see reduced demand for analog IC's.

  20. yalanand
    November 30, 2013

    Not sure analog is that big. Digital firms continue to do better in the stock performance.

    @goafrit2, I think both analog and digital firms are showing good growth. Infact according to Semico Analog Market to Grow 9.5% in 2013.

  21. yalanand
    November 30, 2013

    Nothing is manual these days if you truly spend time to develop some Cadence scripts.

    @goafrit2, I totally agree with you. Languages like Skill definitely helps us to do automation in cadence environment. No doubt such automation friendly languages have greatly improved the efficiency.

  22. yalanand
    November 30, 2013

    That is indeed true – there are a lot of learning and experience that will be needed in the analog integration business.

    @goafrit2, very true. That is the reason analog is considered as one of the most challenging domain to work in. No only analog design is difficult but analog layout is also far more complex that digital design and digital layouts.

  23. yalanand
    November 30, 2013

    Analog is an art not that digital is not.

    @Tom_Terlizzi, I totally agree with you. Initially when I referred to “Art of analog layout” I was wondering why that name was chosen but later I realised that analog is like an art. Analog is more complex compared to digial because its very hard to automate in analog whereas in digital most of the things can easily be automated.

  24. goafrit2
    December 6, 2013

    >> So in the future I dont see reduced demand for analog IC's.

    Even in Intel microprocessors, there are many analog “daughter” circuits around them. There is always an analog block in any product. It will remain a key part of the industry.

  25. goafrit2
    December 6, 2013

    >> I think both analog and digital firms are showing good growth. Infact according to Semico Analog Market to Grow 9.5% in 2013.

    I am not talking about the sector. I mean individual companies. I understand that most sectors are seeing growths, my point is in the valuation of analog and digital companies.

  26. goafrit2
    December 6, 2013

    >> No only analog design is difficult but analog layout is also far more complex 

    That is why it is such a high premium skill to have these days. Some really good ones command north of $150k. Unfortunately, while design is such lucrative,layout cannot claim that.

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