Well, the short (and admittedly not very helpful answer is, that depends.
It depends on what your intended use case is. In a previous post, I highlighted the technical differences between the two Logic Analyzers. In short the Digital Discovery is like the Analog Discovery 2, in that it works with WaveForms 2015, but only has the digital tools. That is, the Logic Analyzer, Pattern Generator, Power Supply, Protocol Analyzer, Static IO and the Script Editor. However, all of these tools have additional channels, higher speed, and additional customization.
The Logic Analyzer uses the high speed inputs on the Digital Discovery, so they can reach 200MS/s at 32 channels, 400MS/s at 16 channels, and 800MS/s at 8 channels. That’s twice the sample rate, four times the sample rate, or eight times the sample rate of the Analog Discovery 2, with up to twice the number of digital channels! So if you’ve ever been using your Analog Discovery 2 and experienced a situation where the sample rate wasn’t high enough or there was too much noise to decipher the higher speeds, or you didn’t have enough channels, the Digital Discovery would be a necessary addition.
It’s also important to note that on the Digital Discovery 24 of the Logic Analyzer channels are just inputs. That means that you could use 24 of the digital inputs on the logic analyzer, and still have 16 channels of digital output. Whereas on the Analog Discovery 2. the 16 channels are shared between the Pattern Generator and the Logic Analyzer.
The other important addition to the Digital Discovery is that the digital inputs and outputs have some flexibility. In the Power Supply tool (along with providing a power supply) you can set the digital input and output specifications to match your system under test. You can change the logic high level and threshold between 5 different values, change the output drive current or leave it at automatic, change the slew rate, and the pull of the pins. This, in my opinion is really the feature that makes it the ultimate embedded development companion.
If you are going into applications where you need flexibility in logic levels, higher speeds for communication or video, or up to 32 channels, then a Digital Discovery would be a worthy purchase. If you want to see the higher sample rate in action, check out this test of the Digital Discovery’s speed on a Seven Segment Display.
To learn more about the Digital Discovery or how to use any of it’s tools, make sure to check out the resource center.