Hello,
I was one of the lucky few selected to receive the evaluation board for the Exar XRP7714ILB-FXRP7714ILB-F quad channel step down controller.
I also attended the online seminar, but because I was kept away from the screen during the second half of it, some of my remarks could actually be answered by the video itself.
I will also refer to the messages posted by Eric Cocquerez and Enrico Migchels in the following thread: http://www.element-14.com/community/thread/4260 so please read it before.
First the package: I received a nice box with the same parts as mentionned by others: The evaluation board, a 110-240Vac to 12Vdc converter, a USB cable and a USB drive with datasheets and a version of PowerStudio on it.
The initial unpacking lead to the following discoveries:
- The converter does not come with the mains cable. Not a big deal, especially considering it is the same format as what is at the back of a computer. It is also only capable to deliver 1.6A, far from the max 5A indicated on the datasheet. One must keep that in mind when intending to test the board without a proper lab supply at hand.
- There are a few 1 pin headers on the board, most of which were slightly bent because of the packing. It was easy enough to get them back straight, but when delivering to rough parts of the world, they may break and I believe they could be quite useful when evaluating the board.
Being naturally curious, I tried to understand what the connectors are for on the board. Most have a clear enough description (GPIO, I2C, LDOOUT, GND) or an obvious use such as the red and black sockets. But there are quite a few others, some even unpopulated which I could not make an idea of what they are.
I tried to look for a datasheet of the evaluation board itself on the enclosed USB drive but could not find it, nor could I find it on the Exar website. That's quite a pity as I believe CON2, HDR1, HDR2, J2, J3, J4, J7 and J8 could make for quite a few interesting developments.
Because I use a WinXP x64 computer as my main developement PC, I had to register on the Exar website to be able to get the 64bits drivers. As Eric mentioned, the account has to be validated by someone at Exar before one can access the resources. Unfortunately for me, this did not happen so I had to go back to my other PC using WinXP 32 bits to follow with the test. Note that it seems this is a Windows only solution here, no Linux to be seen anywhere in the docs.
I'm not as good in power solutions as Enrico appears to be, but just like him I found the XRP7714ILB-FXRP7714ILB-F to be quite good at what it claims to be doing. Not much ripple, good efficiency and most of all, good reporting of what the rails are doing and what the faults are when they occur. This is indeed very handy when developping a remote product that is hardly accessible. One could think of supply chains, packaging systems, onboard power supplies, or, like me, undertable power supply for train modeling. I did not go as far as setting up the whole system as I already have my power solutions (quite archaic, I admit), but this product has quite unlimited applications.
Usage of the Power Studio is quite intuitive even if it can seem quite daunting when new to the field of power management. The first question that came to my mind was "what if I end up with an invalid setup? Could I fry the board?"
As I could not find an answer to this question, I did not go very far in changing the default recommended values but that was enough for an initial assesment of the product.
The only thing that I would have liked to test, and which I did not dare trying, was changing the output voltage while a load is applied to the system. The idea behind this would have been to have a current limited programmable voltage source. I was not sure if it would turn off the output while applying the new voltage recommendation or, even worse, turn the mosfet fully on, thus risking frying the load attached to the board.
I don't believe the webminar answered that question, but if anyone finds out about this, that would be nice.
In the end, this product seems quite good for intelligent power solutions and I believe it can be very useful for industrial applications where precision and information are a must.
As this is my first review here, I hope it was useful to some of you. Do not hesitate to post your remarks about it.
Regards
Olivier
