Hardware handholding

On Nov 4, 1:28 am, Oliver Betz <ob...@despammed.com> wrote:
> Didi wrote:
>
> [...]
>
> >100 MHz bandwidth in pA range (precision is TBD, I assume something
> >modest like 8 bits) is dreamland given your level of expertise as you
> >describe it.
> >It is probably dreamland for anyones level of expertise today, for
> >that,
> >(but I am not sure - I have not looked deeply into it).
>
> 1pA / e = 6E10/s

And 1 eV is 1.6E-19 V
Namely, a logic pin is activated by approximately E19 electrons.
You will get the Nobel prize for measuring individual molecule or
electron.
An MBA getting the Nobel prize in physics will make history.


>
> Oliver
> --
> Oliver Betz, Munich
> despammed.com might be broken, use Reply-To:

On Mon, 03 Nov 2008 15:43:58 -0600, "mitakeet"
<mitakeet@sol-biotech.com> wrote:

>>You can easily find uC with 50 I/Os.  Two of them is far cheaper and
>>easier to deal with then FPGA.  Alternatively, a uC with a simple
>>CPLD.
>
>I thought that you could get FPGAs for not much more than twice that of a
>CPLD and that it was reasonable to get a 100 pin FPGA for $100 or less. 
>Did I do a poor job of research or is $100 reasonable?  At present, I only
>need a single prototype of the hardware and presuming the chip idea works
>the relative volume of the embedded hardware will be several orders of
>magnitude less than that of the chip, so $100 ea. for several FPGAs is not
>a significant issue.  
>
>>But, first of all, you need 100 amplifiers to bring the nA and nV up
>>to 1 to 2V.  
>
>Can the amplifiers be something as simple as some transistors on a PCB?
>
>>You are really asking for a custom analog chip.
>
>I know that ASIC is the way to go, but prototyping those is definitely out
>of my budget.  For a successful commercial product I expect to embed most
>of the control circuitry on the same chip, which should mitigate much of
>the concern.
>
>Thanks again for your help!

As others have pointed out, you need to amplify the signal from your
chip before it can be used by a microcomputer or FPGA.  But first,
since you are not even sure how much current and/or voltage your chip
is putting out, why not see if you can rent or lease test equipment
that can measure really tiny voltages and currents?  Only then will
you know what you are dealing with and if you can use a commercial
op-amp to amplify the signal, or whether you'll have to get something
custom made.  And to keep things simple, I would start out with a
microcomputer to monitor a signal or two, rather than an FPGA.   

-Dave Pollum

Didi <dp@tgi-sci.com> writes:
> On Nov 4, 3:58=A0am, Jim Stewart <jstew...@jkmicro.com> wrote:
> employment if he made it big!!!
> >
> > I think we call it "playing fort" over here in
> > rainy California.
> 
> And I thought it never rained there (at least in southern
> California)... :-)

If it keeps raining, I'll have some lakefront property I'd
like to discuss selling you...

linnix wrote:
> 
... snip ...
> 
> And 1 eV is 1.6E-19 V.  Namely, a logic pin is activated by
> approximately E19 electrons. You will get the Nobel prize for
> measuring individual molecule or electron.
> An MBA getting the Nobel prize in physics will make history.

However, even an MBA will probably accept the 1.5e6 dollar prize.

-- 
 [mail]: Chuck F (cbfalconer at maineline dot net) 
 [page]: <http://cbfalconer.home.att.net>
            Try the download section.

On 3 Nov., 22:43, "mitakeet" <mitak...@sol-biotech.com> wrote:
> >You can easily find uC with 50 I/Os.  Two of them is far cheaper and
> >easier to deal with then FPGA.  Alternatively, a uC with a simple
> >CPLD.
>
> I thought that you could get FPGAs for not much more than twice that of a
> CPLD and that it was reasonable to get a 100 pin FPGA for $100 or less.
> Did I do a poor job of research or is $100 reasonable?

you can probably get a spartan3e with 100 user IOs for less than 10$

-Lasse

On Mon, 03 Nov 2008 12:27:02 -0600, mitakeet wrote:

> As I mentioned, I have no clue how practical even detecting the change
> in current is.  I will have a 10 nm or so channel (3-5 nm deep) with a
> fluid that is mostly water with some number of charged molecules flowing
> through it.  The charged molecules will be around 1 nm in diameter.  My
> goal is to detect the change in current flow between two conductors that
> are broken by the channel.  

OK, so it probably is about DNA sequencing. This is not a novel idea,
there are people working on it for a couple of years. Why not ask them,
especially since they live near you?


-- 
		Przemek Klosowski, Ph.D. <przemek.klosowski at gmail>

linnix wrote:

[...]

>> >100 MHz bandwidth in pA range (precision is TBD, I assume something
>> >modest like 8 bits) is dreamland given your level of expertise as you
>> >describe it.
>> >It is probably dreamland for anyones level of expertise today, for
>> >that,
>> >(but I am not sure - I have not looked deeply into it).
>>
>> 1pA / e = 6E10/s

The correct value is 6E6/s, or 6 million electrons per second.

>And 1 eV is 1.6E-19 V

maybe I missed the joke, but that's wrong. eV is an enery unit, 1eV is
1.6E-19J.

My calc above should demonstrate that 1pA is 6 million electrons per
second. Hard to measure this "current" with 100MHz bandwith.

Oliver
-- 
Oliver Betz, Munich
despammed.com might be broken, use Reply-To:

On Nov 5, 5:05 am, Oliver Betz <ob...@despammed.com> wrote:
> linnix wrote:
>
> [...]
>
> >> >100 MHz bandwidth in pA range (precision is TBD, I assume something
> >> >modest like 8 bits) is dreamland given your level of expertise as you
> >> >describe it.
> >> >It is probably dreamland for anyones level of expertise today, for
> >> >that,
> >> >(but I am not sure - I have not looked deeply into it).
>
> >> 1pA / e = 6E10/s
>
> The correct value is 6E6/s, or 6 million electrons per second.
>
> >And 1 eV is 1.6E-19 V
>
> maybe I missed the joke, but that's wrong. eV is an enery unit, 1eV is
> 1.6E-19J.
>
> My calc above should demonstrate that 1pA is 6 million electrons per
> second. Hard to measure this "current" with 100MHz bandwith.
>

Yes, you are right.  One electron is E-19 Amp, or E19 electrons to get
one Amp one Volt.  I am trying to tell the OP that the odd is E19
against him.

> Oliver
> --
> Oliver Betz, Munich
> despammed.com might be broken, use Reply-To:

On 2008-11-05, linnix <me@linnix.info-for.us> wrote:
>
> Yes, you are right.  One electron is E-19 Amp, or E19 electrons to get
> one Amp one Volt.  I am trying to tell the OP that the odd is E19
> against him.

Oh dear.  One electron is 1.6E-19 COULOMBS.  One electron _per_second_
gives you 1.6E-19 amps.  None of which tells you anything about
the voltage.

-- 
Andrew Smallshaw
andrews@sdf.lonestar.org

On 2008-11-05, Oliver Betz <obetz@despammed.com> wrote:
>
> My calc above should demonstrate that 1pA is 6 million electrons per
> second. Hard to measure this "current" with 100MHz bandwith.

In isolation, that's actually quite doable.  Electron multipliers
can easily detect individual electrons.  I've used them in the past
in the form of photomultipliers.  100MHz is quite fast but ISTR
seeing PMTs with quoted sub-nanosecond response times.  If PMTs
can work at those kind of speeds then plain electron multipliers
must also be able to work at those speeds.

Whilst that's all very interesting I can't see how to use it in
the intended application.  For an electron multiplier to work you
need the electrons to be both fairly energetic and in free space
- it isn't the the kind of thing you connect up with wires.  I
don't think either of those parameters will be easily satisfied in
the OP's app.

-- 
Andrew Smallshaw
andrews@sdf.lonestar.org