We have detected your current browser version is not the latest one. Xilinx.com uses the latest web technologies to bring you the best online experience possible. Please upgrade to a Xilinx.com supported browser:Chrome, Firefox, Internet Explorer 11, Safari. Thank you!

Just arrived: Digilent’s $279 Analog Discovery 2 multi-instrument based on a Spartan-6 FPGA and a ton of ADI chips

by Xilinx Employee ‎08-04-2017 03:11 PM - edited ‎08-04-2017 04:13 PM (40,238 Views)


A new toy arrived this week from Digilent: the pocket-sized Analog Discovery 2. Actually, I’m purposely being quite unfair. The Analog Discovery 2 is not a toy. It’s a nicely designed USB multifunction analog and digital instrument that combines:



  • A two-channel USB digital oscilloscope (1MΩ, ±25V, differential, 14-bit, 100MS/s, 30MHz+ bandwidth - with the Analog Discovery BNC Adapter Board)
  • A two-channel arbitrary function generator (±5V, 14-bit, 100MS/s, 12MHz+ bandwidth - with the Analog Discovery BNC Adapter Board)
  • A stereo audio amplifier to drive external headphones or speakers with replicated AWG signals
  • A 16-channel digital logic analyzer (3.3V CMOS and 1.8V or 5V tolerant, 100MS/s)
  • A 16-channel digital pattern generator (3.3V CMOS, 100MS/s)
  • 16 channels of virtual digital I/O including buttons, switches, and simulated LED indicators
  • Two input/output digital trigger signals for linking multiple instruments (3.3V CMOS)
  • A digital voltmeter (AC, DC, ±25V)
  • Two programmable power supplies (0…+5V , 0…-5V in 0.1V steps), powered from USB or a wall wart for more current



From these basic instrumentation resources, the Analog Discovery 2’s companion software package called Waveforms 2015 synthesizes some even more complex and very useful instruments including:



  • A network analyzer – Bode, Nyquist, Nichols transfer diagrams of a circuit. Range: 1Hz to 10MHz
  • A spectrum Analyzer – power spectrum and spectral measurements (noise floor, SFDR, SNR, THD, etc.)
  • Digital Bus Analyzers (SPI, I²C, UART, Parallel)



The retail price for this all-in-one instrument is $279, which represents tremendous bang for the buck. You can do a lot of serious work with this product.


Like its close lookalike sibling, the $199.99 Digilent Digital Discovery, and its immediate predecessor, the Digilent Analog Discovery, Digilent’s Analog Discovery 2 derives much of its flexible nature from a Xilinx Spartan-6 FPGA. What’s the difference between the Analog Discovery 2 and the Digital Discovery? Digilent’s Kaitlyn Franz answers this question in two recent blog posts titled “Analog Discovery 2 vs Digital Discovery – A Battle of Logic” and “I Have an Analog Discovery, Do I Need a Digital Discovery?


I’ll let Kaitlyn’s comparison chart from her blog explain it succinctly:



Digilent Analog and Digital Discovery Comparison Chart.jpg 



Thanks to a number of analog ICs from Analog Devices, the Analog Discovery 2 has analog measurement capability, two analog arbitrary waveform generators, and two programmable power supplies. By comparison, the Digital Discovery has more logic-analysis channels and a much faster maximum sample rate of 800Msamples/sec. That both of these products rely on a Xilinx Spartan-6 FPGA for their flexibility and programmability says a lot about basing the products’ design on an FPGA. It also shows that clever engineering can extract a lot of performance from an FPGA that’s considered by many to be a “low-end” part.


Here’s a block diagram of the Digilent Analog Discovery 2, taken from the Reference Manual:




Digilent Analog Discovery 2 Block Diagram v2.jpg 




The Reference Manual also contains detailed descriptions and a theory of operation with schematics for all of the Analog Discovery 2’s sections. That’s so you can see how the Analog Devices’ parts (and the Xilinx Spartan-6 FPGA) were used in the design. Digilent wants this product to be a teaching tool in multiple dimensions.


In an homage to a couple of my favorite engineering YouTubers—EEVblog’’s Dave “Don’t Turn it On, Take it Apart” Jones from Australia and AvE (“Arduino Versus Evil,” and unfortunately I can’t repeat his signature phrase in Xcell Daily) from Canada—I popped the transparent covers off of the Analog Discovery 2 for some close-up photos of the two sides of its pcb:




Digilent Analog Discovery 2 Board and Case.jpg 





Digilent Analog Discovery 2 Board Top.jpg 





Digilent Analog Discovery 2 Board Bottom.jpg




That’s a fairly busy 2-sided load resulting in a very compact product.


I plan to put the Analog Discovery 2 through its paces in the near future using the new Xcell Daily Hardware Lab I’ve set up and I’ll chronicle the results of those experiments in future blog posts.



For more information about the Digilent Analog Discovery 2 in Xcell Daily, see “$279 Analog Discovery 2 DSO, logic analyzer, power supply, etc. relies on Spartan-6 for programmability, flexibility,” For more information about the Digilent Digital Discovery, see “$199.99 Digital Discovery from Digilent implements 800Msample/sec logic analyzer, pattern generator. Powered by Spartan-6” and “Hands On: Testing the $199.99 Digilent Digital Discovery Portable Logic Analyzer (based on a Spartan-6 FPGA).”



For more information about either of these instruments, contact Digilent directly.