PSoC Express: Does it work for semi-analog designs?

[Joerg]

| > Out of memory I would say you looked up the wrong type. It is not always best to just sort the variants in dollars.
| > OK, that is not much help.
| >
|
| Yes, it was just an example. Express won't let you select a type that's
| too cramped.

Oh sorry, I forgot you use Express. It don't come to mind how to select a device there. Sorry, I use Designer.

And possibly Express might hit the ceiling here, which means another
learning curve. Or maybe I chicken out and do it analog again ;-)

|
|
| > Start with the 29466 or such to prototype. It is easy to replace if burned (socket!) and have rich resources to play. So much
| > resources that is possible to make target and test generator on the same part for development.
| >
| > If you know later on what you really want and how to implement, then downgrade. The 24123 or such is a nice little 8-pin device
and
| > fits the same socket as the 29466 if you can switch the VCC pin. There is an app note with all types listed!
| >
|
| I also would have to make sure that whatever I use is either small or
| available in MLF or similar. Can't get any big fat chip into this design.

The app note lists all devices in nice table with package type.

Yes, but it also needs to have no significant lead time. IOW, places
like Digikey should have it. We use that as a "weather forecast" for
availability. If they don't have something that's usually not a good sign.

 

[Henry Kiefer]

Impossible declared jobs seem to attract Joerg

- Henry

--
www.ehydra.dyndns.info


| Henry Kiefer wrote:
|
| > | I was just using it as an example, plus because they are in stock
| > | locally. On this one I'll have to run a rather fast switcher, basically
| > | like creating a 120V inverter with a true sine wave. It has to run above
| > | 100kHz because there isn't much space for magnetics. Have to talk to the
| > | client tomorrow. If it's like usual where they need it "yesterday" I
| > | might do it analog just one more time (and ask for forgiveness...).
| >
| > EL converter?
| > Hm.
| >
|
| No. But my lips must remain sealed for now. The whole thing is slow but
| it has to run off a battery voltage that's only 1/8th of what the load
| needs and in about the space of a slim USB stick.
|
| --
| Regards, Joerg
|
|

 

[Henry Kiefer]

| > | I also would have to make sure that whatever I use is either small or
| > | available in MLF or similar. Can't get any big fat chip into this design.
| >
| > The app note lists all devices in nice table with package type.
| >
|
| Yes, but it also needs to have no significant lead time. IOW, places
| like Digikey should have it. We use that as a "weather forecast" for
| availability. If they don't have something that's usually not a good sign.

Yes, that is a problem in general. I bought several hundred of the small ones and if a small one cannot fit I place two
(Something chinese people cannot do *lol*)

In Germany you can buy PSoC almost with distributors only.

- Henry

 

[Joerg]

Henry Kiefer wrote:

Impossible declared jobs seem to attract Joerg

That's the fate of many consultants. We get called in after pretty much
everyone from the staff has thrown in the towel ;-)

 

[Joerg]

| > | I also would have to make sure that whatever I use is either small or
| > | available in MLF or similar. Can't get any big fat chip into this design.
| >
| > The app note lists all devices in nice table with package type.
| >
|
| Yes, but it also needs to have no significant lead time. IOW, places
| like Digikey should have it. We use that as a "weather forecast" for
| availability. If they don't have something that's usually not a good sign.

Yes, that is a problem in general. I bought several hundred of the small ones and if a small one cannot fit I place two
(Something chinese people cannot do *lol*)

In Germany you can buy PSoC almost with distributors only.

I've lived there as well and that is what I never understood. Over here
you've got to offer much of your products through the places that are
used for prototyping. When I am done with a design my clients expect a
part list for the proto run that should ideally be all from one place.
Usually Mouser or Digikey. This is what some (large) EU mafg don't seem
to understand and why their design-in rate is now so low.

 

[Henry Kiefer]

| Henry Kiefer wrote:
|
| > | > | I also would have to make sure that whatever I use is either small or
| > | > | available in MLF or similar. Can't get any big fat chip into this design.
| > | >
| > | > The app note lists all devices in nice table with package type.
| > | >
| > |
| > | Yes, but it also needs to have no significant lead time. IOW, places
| > | like Digikey should have it. We use that as a "weather forecast" for
| > | availability. If they don't have something that's usually not a good sign.
| >
| > Yes, that is a problem in general. I bought several hundred of the small ones and if a small one cannot fit I place two
| > (Something chinese people cannot do *lol*)
| >
| > In Germany you can buy PSoC almost with distributors only.
| >
|
| I've lived there as well and that is what I never understood. Over here
| you've got to offer much of your products through the places that are
| used for prototyping. When I am done with a design my clients expect a
| part list for the proto run that should ideally be all from one place.
| Usually Mouser or Digikey. This is what some (large) EU mafg don't seem
| to understand and why their design-in rate is now so low.

I don't think that you really don't know the answer:
In Germany it is much more important you can say "I've done it", than "It was solved" !
So the natural answer is to provide a list of unique items then a general list focused on a single source to speed all up.

- Henry

 

[Joerg]

| Henry Kiefer wrote:
|
| > | > | I also would have to make sure that whatever I use is either small or
| > | > | available in MLF or similar. Can't get any big fat chip into this design.
| > | >
| > | > The app note lists all devices in nice table with package type.
| > | >
| > |
| > | Yes, but it also needs to have no significant lead time. IOW, places
| > | like Digikey should have it. We use that as a "weather forecast" for
| > | availability. If they don't have something that's usually not a good sign.
| >
| > Yes, that is a problem in general. I bought several hundred of the small ones and if a small one cannot fit I place two
| > (Something chinese people cannot do *lol*)
| >
| > In Germany you can buy PSoC almost with distributors only.
| >
|
| I've lived there as well and that is what I never understood. Over here
| you've got to offer much of your products through the places that are
| used for prototyping. When I am done with a design my clients expect a
| part list for the proto run that should ideally be all from one place.
| Usually Mouser or Digikey. This is what some (large) EU mafg don't seem
| to understand and why their design-in rate is now so low.

I don't think that you really don't know the answer:
In Germany it is much more important you can say "I've done it", than "It was solved" !
So the natural answer is to provide a list of unique items then a general list focused on a single source to speed all up.

I have never worked in a German company, it was always US corporations.
But the engineers were often Germans and they thought the same as I did:
"Why is there no Digikey out here?"

 

[Henry Kiefer]

| I have never worked in a German company, it was always US corporations.
| But the engineers were often Germans and they thought the same as I did:
| "Why is there no Digikey out here?"

I don't understand what you mean.
You can buy digi-key, they will ship to Germany.
Something similar is Bürklin here.

- Henry

 

[CBFalconer]

.... snip ...

I was just using it as an example, plus because they are in stock
locally. On this one I'll have to run a rather fast switcher,
basically like creating a 120V inverter with a true sine wave. It
has to run above 100kHz because there isn't much space for
magnetics. Have to talk to the client tomorrow. If it's like usual
where they need it "yesterday" I might do it analog just one more
time (and ask for forgiveness...).

If you start with 6x the output frequency, and generate the
following waveforms, you can mix the outputs to create a sine wave
with no harmonics below the 5th, and no even harmonics.

__--____ __
--
______
______

__--__
sum: __ __
--

These can be conveniently generated with a three bit shift
register, or a PLA. If needed the higher harmonics can be fairly
easily rejected. Taps on an output transformer can do the mixing
with minimum losses. Very stable.

 

[Joerg]

| I have never worked in a German company, it was always US corporations.
| But the engineers were often Germans and they thought the same as I did:
| "Why is there no Digikey out here?"

I don't understand what you mean.
You can buy digi-key, they will ship to Germany.
Something similar is Bürklin here.

I can only relate back to the early 90's. Back then you couldn't order
easily from Digikey and the local ones in Europe didn't nearly have the
wide selection that you needed with an analog design. The digital guys
had it easy, they could order all the TTL chips and GALs at one place,
usually. Unless they needed some hotshot ECL. Now you also have Farnell.

But I must say that the distributors like EBV, Spoerle and others were
very helpful. Can't complain. The only thing that regularly irked them a
bit was that meetings or presentations in our company could only be held
in English.

 

[Joerg]

Joerg wrote:

... snip ...



If you start with 6x the output frequency, and generate the
following waveforms, you can mix the outputs to create a sine wave
with no harmonics below the 5th, and no even harmonics.

__--____ __
--
______
______

__--__
sum: __ __
--

These can be conveniently generated with a three bit shift
register, or a PLA. If needed the higher harmonics can be fairly
easily rejected. Taps on an output transformer can do the mixing
with minimum losses. Very stable.

Here I'll have to regulate a load that is variable. Basically a -20V to
+20V sine into a few kohm. It'll all come out of a rather wimpy 3V
battery that sags a lot under load. At least the load is resistive. The
H-bridge is a whole 'nother story because I practically don't have any
real estate for it :-(

 

[Klaus Kragelund]

Either that or use a mux up front and ping-pong, then average in SW. In
the analog world I usually just clamp it away. That's why the sales guys
have such a hard time talking me into opamps that cost more than 10
cents ;-)

Ping pong? Do you mean to use a comparator to make a 1bit ADC and
averaging? (using an output to create the LSB dither)

Regards

Klaus

 

[Joerg]

Ping pong? Do you mean to use a comparator to make a 1bit ADC and
averaging? (using an output to create the LSB dither)

Basically yes. But it will come at the price of some code overhead. So
far in my career I have been lucky and never had to resort to any of the
fancy auto-zero amps. Except for a laser TEC controller but only because
it had them already built-in so they didn't cost extra.