原创 Analogue made more digital (designer) friendly

Embedded system designers dwell largely in the digital domain, but the world is mostly analogue, so that means that to some degree they must be familiar with the methods and techniques for transforming that real world into a form they can manipulate in their designs.

In most cases that has meant having at least one member of a product development team who was an analogue design specialist or, alternatively for the digital designers to become more expert in designing in the analogue domain.

Some recent product introductions seem to me indicative of yet a new wave of tools and component strategies that make integration of analogue and digital functions easier.

The three approaches I am talking about here are the analogue library introduction from Texas Instruments, Cypress Semiconductors' new 5LB PSocÿ and recent associated tool upgrades, and the component building block approach Silicon Laboratories has taken in its SiM3U1xx/SiM3C1xx Precision32 MCUs. They seem to me to be targeted at different segments of the developer market, with some overlap.

TI's board-level analogue library
TI's precision analogue design library offering is aimed at helping in the development of board-level precision designs in a way that allows engineers to quickly evaluate and customise their systems as well as build up their analogue knowledge base.

With about 20 available now for download, the TI Precision Designs library includes categories of reference, verified and certified Designs that provide all of the methodology and results, and design and simulation files needed to quickly evaluate and customise designs.

Silicon Labs' component-based approach
Silicon Labs has taken the traditional ADC/DAC MCU integration approach one step further in its SiM3U1xx/SiM3C1xx MCUs. Its design approach takes into account that DACs and ADCs are often integrated into MCU design for more than the necessary conversion from one domain to the other, but use in such critical linear functions as bias current generators, arbitrary waveform generators or as a relatively noise-immune communication medium.

For example, this family of MCUs has an on chip current DAC (IDAC) used in combination with an onchip FIFO structure. Together they implement a looping capability that extends the precision of the IDAC from 10 bits to 12 bits at one-fourth the data rate by interpolating between adjacent 10 bit values without DMA intervention

So if the developer uses it to output three identical values of "x" and a fourth value of "x+1", the IDAC output as measured at the package pin will be a 12bit precision allowing it to be used to generate a 12bit precise bias current.

Cypress approach to analogue integration
Similar to other earlier members of the Cypress PSoC repertoire the 5LP family supports a wide range of analogue library functions the developer can use.

For example, the PSoC 5LP has a 20bit differential Delta-Sigma ADC, and two 12bit, 1 MSPS differential SAR ADCs for analogue to digital conversion. In addition to these ADCs, it has an internal 0.1% voltage reference, and other analogue components such op-amps come in handy to integrate the discrete circuitry that is required to interface with the analogue real-world.

Where to next?
There are obviously a wide range of other approaches previously introduced which have it as their aim to make it easier for developers to integrate analogue and digital functionality into their designs with something like the degree of flexibility they do integrating digital functions.

Of course, these tools are specific to the particular company devices. But in a general sense, if there were cross-platform versions of these tools, would they be used largely by specific segments of the embedded design community? Or are there circumstances where the different approaches would be useful on the same project?

These products are, of course, only the most recent examples of a continuing trend. What other such tools and approaches have you heard about? How to they compare with these offerings?

As many of you know from conversations with me, I often like to push beyond the immediate market needs or opportunities. I tend to push out to the edges beyond the one or two year time frame on which they are focused. I also want to know answers to what they consider blue sky questionss about where things go next.

In that context, my at (or over) the edge question is: Are high level analogue/digital design platforms possible similar in capabilities to the SoC hardware/software integration virtual platforms, offered by companies such as Mentor Graphics, Synopsys and Cadence?

Obviously those hardware/software co-development platforms are targeted at segments of the embedded market where complex MCU core-based designs are needed. But could they be extended to provide some degree of integration and co-development between analogue and digital?

As far as I can see in my investigation on Google and some of the scholarly search engines, except for university and research institute papers I have found little in the commercial world like what I am imagining. Am I wrong? Unrealistic? Impractical? Let me know if you are aware of such environments.

And stepping back from the edge to the here and now, if you have used the TI, Cypress or Silicon or other similar approaches and have experiences that you would like to share leave your comments here.