In the last decade, test and measurement devices have been getting significantly smaller and more intelligent. Devices that used to take up a large portion of a desktop are now fitting in the palm of your hand. One group that has been leading this trend is the Saleae group out of San Francisco, California. The company, started in 2008 by brothers Mark and Joe Garrison, set out to design a new class of test equipment. The result was their original Saleae Logic -- an 8-channel logic analyzer that was under 2" square.
Fast forward to today, at 1:00 a.m. ET, Saleae released a new family of devices. This family distinguishes itself from the original product line by incorporating analog measurement capabilities. Previously, Saleae Logic devices were available with 8 and 16 channels. The new mixed-signal logic family lineup consists of four new devices ranging 4 to 16 inputs. The devices are intended to fill a gap between data recorders and oscilloscopes. Except for the Logic 4, each channel supports dual use for both analog and digital signals. This means you can extract both analog and the digital information at the same time. This is a nice feature if you are looking to troubleshoot low speed signals and want to see if the envelope (shape) of the waveform is affecting the digital signal.
The new mixed-signal logic analyzer family from Saleae
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The performance of the devices has also been expanded at the top end. The previous Logic and Logic16 devices had a max digital sampling rate of 24MS/s (mega-samples per second) and 100MS/s respectively. The newest devices max out at 500MS/s. On the analog side of the equation, the maximum sampling rate that can be had is 50MS/s. This equates out to about 5MHz of bandwidth at the -3dB point. While this may not be a lot of analog bandwidth, it should give some ability to begin troubleshooting out in the field. The fact that Saleae provides a complete SDK means you can also port out the data for analysis in MATLAB or other post-processing tools. Using alternative filtering techniques, one may be able to push up the -3dB point.
Technical specifications of the Saleae mixed signal logic analyzer family
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The one feature about these devices that really stands out are their small size. The 8-channel devices are about the size of the box Microchip uses to send their chip samples in. This form factor provides great advantage in that it will not take up a lot of space in your workshop. Also, the small size of these devices means you can drop one in your travel bag and easily take it to a remote test site. Unlike some other devices, this logic analyzer comes in an enclosure made of anodized, 6061-T6 aluminum. This is a structural-grade aluminum (some might call this aerospace grade, but -- to be honest -- this is what we use when we really do not have much load. I'm sorry; the mechanical designer is coming out in me).
All of this is great, but what about the interface? Having used another logic analyzer in the past, I can say that Saleae has not only created a well-crafted physical product, but that their user interface shows similar attention to detail. For those wanting to get a basic introduction to Saleae's user application, their website has a series of videos that show it in use. Included in the application are at least 19 different protocols that can be decoded. The application provides the ability to annotate, search, and share, as well as other tools for analyzing the signal. If, for some reason, you need some ability not found in their application, there is a full SDK allowing you to interact with the device as needed. As the device is a streaming device, the length of time that it can record a signal is based upon the installed RAM on the client side. There is a tool on the Saleae website that provides an estimate of the length of signal that can be recorded based upon the device selection and the number of channels in use.
In all, it looks like Saleae is offering a fantastic device. Saleae has launched the product via a crowd-funded methodology. Their purpose in this is to help fund the initial production lot. This will enable them to build inventory to prevent out-of-stock issues in the future. In the next few weeks, I will be looking at a sample and putting it through its paces. I will report back the final impressions I have on the device and compare it against some other products out on the market. Is there anything that you would particularly like me to test once I get this device? If so, please let me know in the comments below, and I will try and perform as many tests as I have the time to do.