Arduino users?

On 12/03/14 19:08, John Devereux wrote:
> Grant Edwards <invalid@invalid.invalid> writes:
> 
>> On 2014-03-12, John Devereux <john@devereux.me.uk> wrote:
>>>
>>>> I do not trust the POR/BOR on them at all. But that goes for most uC, it
>>>> seems uC designers have a hard time with threshold detectors or the
>>>> respective companies don't have enough analog talent.
>>>
>>> Anything that is the slightest bit analog they get wrong. (Generally,
>>> not Atmel specifically). BOD, POR, clock PLLs, voltage references,
>>> ADCs. Startup, Real time clocks, sleep current.
>>
>> In my experience, TI does a better job than most when it comes to the
>> analog stuff on uControllers, but it does seem that putting analog
>> stuff on the same die as a CPU results in generally sucky analog
>> stuff.
> 
> I guess the process is tuned for, say, flash memory and everything else
> just has to work with that.
> 

Yes, that's definitely a big part of the problem.  When you make a pcb,
you have choices about the number of layers, the thickness of the
layers, width of tracks, types of vias, power layers, coatings, etc.
You pick different combinations for boards that are high-speed digital,
accurate analogue, low-power, high current, etc.  Chip design is
somewhat similar, but there are more factors, they make a bigger
difference, and they are harder to mix on the same die.  So mixing
digital parts, memory, power parts and analogue parts on the same die is
always going to mean compromises.

> The other leading edge analog vendor is ADI, and they are the only ones
> I would trust to put an ADC on a CPU chip. Trouble is their digital
> peripherals are clunky.
> 
> These look pretty powerful:
> 
> <http://www.analog.com/en/processors-dsp/cm4xx/products/index.html>
> 
> I have not tried any TI micros yet, they were late in the game with ARMs
> IIRR.
> 
>