Almost a year ago I did a comparison of Zynq SoMs, or System-on-Modules, these handy little Zynq-based devices that speed up your product development by taking the risk out of your PCB design and often handing you a ton of working example code. Well there have been many more Zynq SoMs come onto the market since then, so another comparison is due, but today I just wanted to review one of them: ZynqBoard, the smallest Zynq SoM on the market today according to zynqboard.com. This new device measures only 42mm x 22mm! To get it so small it’s developers have stripped it down to only the essentials: Zynq, DDR3, flash memory, clock oscillator and expansion connectors.
Normally I’d write about all the features, but in this case, I think that the value of this SoM doesn’t come from it’s “features” but instead from what it doesn’t do:
- It has no ON-OFF switch
- It has no RESET switch
- It has no LEDs
- It has no programming connector
- It has no on-board power supplies
- It has no Ethernet PHY
- It has no USB PHY
- It can’t be used as a stand-alone device
That’s right, this board can’t be used as a stand-alone device, in fact, in order to even turn this thing on you have to design your own carrier board for it. Although that may sound like a drawback to some, the total freedom to customize this board to your application is this SoM’s powerful value proposition. It’s so small they didn’t even have space for the company logo! But with such a small footprint, it’s hard to justify not using it - here’s what I mean…
So you need a Zynq in your product, and you decide to put it directly on your custom board. This ups your layer count to at least 8 (maybe more, the ZynqBoard has 16), it increases your assembly cost (BGAs, two sided board), it inflates your bring-up time and it obliges you to do critical DDR3 routing. In general terms, it significantly increases the complexity of your board design and in turn increases your risk of doing re-spins and spending too much time bringing up your board. Why would you go that route when for practically the same amount of real-estate, you can put a tiny Zynq SoM on your board and be done with it. Engineers like the challenge of doing things from scratch, but the guy who’s paying the bills wants to have a product yesterday, and the best way of achieving that is by leveraging these SoMs.
Overall, I like this new Zynq SoM and I admire the boldness it took to develop a product that does less than those of the competitors.
Update 2016-03-12: I got in touch with Servaes Joordens from zynqboard.com and he tells me that the price for low quantities of the ZynqBoard is 200 euros.