
Analog's answer to FPGA opens field to masses (2008) - pointfree
http://www.eetimes.com/document.asp?doc_id=1167814
======
pointfree
Fast forward 6 years and it looks like they are available from a company
called Anadigm (
[http://www.anadigm.com/fpaa.asp](http://www.anadigm.com/fpaa.asp) ).

This sounds like it could be a great fit for Software Defined Radio.

~~~
mikepurvis
Dev kit is $200. Chip is listed at Arrow for ~$10, but out of stock.

I wonder if you could do some interesting analog audio stuff, like building
low part count multi-speaker crossover networks, etc. Then again, for $10
apiece, it probably still makes way more sense to just put a cortex or
something on there and do it all digitally.

~~~
_-__---
You could market it to the analog-or-nothing crowd in the audio community.
Decreasing production time of "boutique" analog clone effects pedals could
make you some cash.

~~~
mikepurvis
That would be neat— a reconfigurable effect pedal that you could download and
install new patches for.

The _real_ trick would be providing the option to route the signals out of
this thing and through vacuum tube stages, so you're not stuck trying to build
a decent overdrive or compressor with silicon-only components.

------
reisgabrieljoao
_Rough estimates suggest there are around 3,000 analog engineers in the world_

That's the real order of magnitude of the number of analog engineers?

~~~
swamp40
Very few people use analog signal processing techniques these days.

It used to be common up until about 10-15 years ago, but then DSP's came
along.

Now, you take a signal, buffer it by the minimuum amount necessary to get it
into the DSP, and call it a day.

The best case is, you don't touch the signal at all, because any caps,
filters, op amps can all distort the original signal.

You can do it all digitally, and it's much easier to modify on the fly if your
technique isn't working well.

Boards and boards full of touchy analog electronics have been replaced by a
single DSP.

And not many people are looking back.

~~~
agoetz
Signal conditioning is still an important part of EE design. Not all signals
are TTL level and unipolar.

For example, this appnote[0] uses a Delta-Sigma converter to digitize a load
cell, with the ability to "detect one sheet of copier paper dropped on a stack
of 20 reams". In order to do this, it relies on an intrumentation amplifier
and custom correlated-double sampling to get a measurement accurate to 200,000
counts.

And even if your input signal can be directly input to your ADC, you'll still
need an analog anti-aliasing filter.

Signal conditioning is an important part of signal processing that has to
happen in the analog domain.

[0] [http://cds.linear.com/docs/en/application-
note/an96fa.pdf](http://cds.linear.com/docs/en/application-note/an96fa.pdf)

~~~
swamp40
I agree that we haven't yet eliminated _all_ analog conditioning.

Your example however, doesn't really bolster your point.

Delta-Sigma modulation is a _digital_ signal processing technique.

That particular chip is also using a _digital_ FIR filters to reduce noise.

------
Animats
You don't get that much analog per chip yet. See

[http://www.anadigm.com/_doc/DS231000-U001.pdf](http://www.anadigm.com/_doc/DS231000-U001.pdf)

Basically, it's four op amps, plus programmable circuitry for all the
accessory stuff needed to build most of the things you can do with four op
amps. This is neat, but four op amps isn't much analog computation. Here's the
block diagram of a classic, very successful analog control system: the F-16's
original stability control system:
[http://thelexicans.files.wordpress.com/2013/07/yf16fcs.png](http://thelexicans.files.wordpress.com/2013/07/yf16fcs.png)

So this isn't for analog computation, it's for front-ending digital systems
where you need to do some filtering at a faster speed than a DSP approach can
handle.

The Cypress PSoC line seems to be a whole ARM processor with a little analog
stuff added.

------
drone
Too bad the market is still tough for low-volume FPAA's (vs. FPGA's). A
product I was working on last year desperately needed FPAA's in low volumes
(think 1k-2k MOQ), and was shelved largely because the lack of market
availability.

The design was changed to reflect the lack of availability of a low-volume
FPAA at a reasonable price point, but this drove the feature set down and the
price up until the product was shelved. Until they make them as easily
available and as low-cost and many comparable FPGAs, it's going to be hard to
design niche-market products around them.

~~~
TTPrograms
What's the difference between a FPAA and the programmable analog blocks on
products like Cypress' PSOC? Those chips are pretty common.

~~~
drone
In our experience, the primary issues was the available number of analog I/Os,
we were doing large-scale matrix-like switching between analog sources. That
is to say, the PSoCs contained a small number of analog I/Os that could be
routed relative to a "dedicated" FPAA.

------
kens
This article is from 2008. Is there any particular reason its here?

~~~
pistle
This. I was about to bring up the Anadigm source and then saw the date. Not
sure why this is news since there are products in the market and demand scale
has not surfaced to help ramp up the supply availability and product
variations that could make it a healthy market.

------
deutronium
I recently bought some FPAAs from Anadigm, specifically the 3.3V version:
AN231E04-E2-QFNSP

Interestingly they use a switched-capacitor design, which means you can only
input signals lower than the clock frequency used for switching the caps.

I had a look for continuous-time FPAAs but couldn't find any.

My goal is simply to make a guitar FX pedal with them, as they can alter gain,
perform filtering such band-pass etc.

Potentially I could see it having lower latency than DSP, if anyone knows more
about that, I'd be very curious.

~~~
alecdibble
If you are interested, I did some research on extremely fast, lower power, and
low noise filtering using FPGAs or CPLDs.

~~~
deutronium
Sure, that sounds cool! (I've got a cheap FPGA dev board that's got an ADC/DAC
on, that I wouldn't mind putting to good use)

~~~
alecdibble
Most of the research work was targeting a specific development paltform, so I
don't have good instructions for doing it generally. Here is the paper we
based our research off of:
[http://www.eecg.toronto.edu/~johns/ece1371/papers/1993_lewis...](http://www.eecg.toronto.edu/~johns/ece1371/papers/1993_lewis.pdf)

Here is my presentation poster which should explain the motivation and theory
a little more clearly than the paper:
[https://www.ece.ucsb.edu/academics/undergrad/capstone/event-...](https://www.ece.ucsb.edu/academics/undergrad/capstone/event-2012/presentations/flexSD-
poster.pdf)

I graduated before we got it releasable, and haven't had much time with my job
to finish up the project. I don't have more time to add to this explanation,
but if you want more info or implementation help, feel free to email me:
alecdibble at gmail dot com.

------
blt
I wonder if you could use it to build a synthesizer. That would be amazing - a
modular analog synthesizer on a chip.

~~~
boomlinde
I believe I read a while that they demonstrated it in a synthesizer
application at a music expo, and I've heard rumors that they are already used
in some commercial analog synthesizers.

~~~
fit2rule
Audio-synthesis has been using these kinds of technologies for decades. Its
not unusual for synth/audio-processor manufacturers to make their own custom
ASIC's, FPGA's, even small-quantity chipfab runs, to provide their IP to the
customer. Synthesis is very promiscuous in this regard; you can make sound
with a surprising number of things in the universe.

~~~
boomlinde
I well aware of the prevalence of the technologies you list in the synthesizer
industry, but custom ASICs or FPGAs are quite obviously not the same thing as
FPAA.

~~~
fit2rule
If there's a way, the synth nerds will use it.

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mdturnerphys
Two of the sub-comments here mention them, but anyone interested in this sort
of chip should check out Cypress's PSoC line.

