Generating an IV Curve easily is possible with the SpikeSafe SMU, a pulsed source measure unit. No special equipment, programming or sequence code is required. Easily validate vendor IV Curves to ensure your product development and research efforts are efficient. In this video, you will learn how to generate a High Power IV Curve using the SpikeSafe Pulsed Source Measure Unit.    


A member of Vektrex’s Engineering Team, walks us through the generation of an IV Curve using Vektrex developed Control Panel Software Application and the SpikeSafe Source Measure Unit (SMU) 5A model. You do not need to take time to write your own code or press a lot of buttons to generate this IV Curve.  

The load used for this demonstration is a simple chip on board part with a max current of 2A and a forward voltage of 30V. This demonstration features a 4-wire measurement with 1 pair on the force terminals and 1 pair on the sense terminals.

Steps to Generating an IV Curve 

  1. Connect to the SpikeSafe. Once it’s connected, we should see a section appear in the left-hand panel for the unit’s internal digitizer, which will be taking all our voltage measurements.
  2. Set our current source to Pulsed Sweep mode. We’ll leave most of the settings at their default values.
  3. Under Pulse Options, switch to “Duty Cycle/Pulse Width” and do a duty cycle of 1% and a pulse width of 200uS. Under “Pulse Sweep Settings”, do 0.2 A to 2A in 20 steps, which should give us a nice high-resolution curve and click Apply.
  4. Next, switch over to the Digitizer tab. In the Digitizer Settings panel we can see that all of our settings have been auto-calculated by Control Panel, so that we’ll get a single voltage reading for every pulse in the sweep. With that, we’re ready to take some measurements.
  5. Click ‘Start Measurement’ on the Digitzer so that it’ll be ready and waiting for a trigger from the SpikeSafe. Then start the channel, hit the Pulse button and stop the channel. You can see all our data have been plotted on the graph in the middle of the screen.
  6. The only thing left to do is to go over to the Graph Settings panel and click the “Graph I/V Curve” checkbox. Control Panel then replots the data so that our voltage measurements are on the x-axis and all of those voltages are matched up with their respective set currents on the y-axis.
  7. If you’re happy with this graph, right click to export it to an image (and save that anywhere on your computer) or go down to the Statistics panel and click Export to Excel to save the data to a CSV file which can then be opened in Excel.

That’s how easy it is to generate the I/V curve for an LED (or any other device) in Control Panel using a SpikeSafe SMU. 

Vektrex designs and manufactures high performance LED test solutions for leading manufacturers and LM-80 labs worldwide. Visit to learn more about our products and solutions.

Learn more about the SpikeSafe SMU. 

About Melissa Ford

Melissa Ford is the President and CEO of Vektrex. In this role, Ms. Ford created the Vektrex vision—to innovate and produce advanced, high quality, forward looking solutions that reduce global greenhouse gas emissions for our clients and partners in the semiconductor industry. Ms. Ford has focused the company on this vision, guiding it steadfast in the direction of products, replacing its service only business. Vektrex, under Ms. Ford’s vision and direction, advances the industry globally by defining and setting the standard for high quality LED reliability. Vektrex is the world leader in technology used to measure LED lighting reliability. The company products are made in the USA and distributed worldwide.