When Tektronix released the Keithley IVy for its 2600B source measure unit (SMU), it became the most hands-on, useful app of the now four Tektronix iPhone and three iPad apps in the iTunes App Store. That’s because a user can actually control the unit, perform measurements, and then share the results.
As the name implies, the IVy app is actually a transistor curve tracer, characterizing current versus voltage (I-V curves) for transistors using the 2600B SMU as the tracing unit (Fig. 1). You input some key parameters on the app and the SMU will go off and perform the tests. Then you can view the curves, zoom in on anomalies, and subsequently share the curves with team members or customers to troubleshoot issues.
Tektronix actually introduced the first IVy app to the Google Play store for Android devices in 2014. However, it quickly became clear that some improvements were needed if it was to fulfill the original mission to “completely change how designers interact with and exchange information,” according to Mark Hoersten, vice president of business development at Tektronix.
First and foremost, the original app interfaced to the 2600B SMU over a front-panel USB connection. Users (naturally) wanted wireless, so the app was updated to allow for connectivity over a local Wi-Fi access point, with the 2600B connected to the network via a LAN port.
The original Android version of IVy was updated to support wireless, and the iPad/iPhone version supports wireless “out of the box.” It can be used with one- or two-channel SMUs, and is able to source and measure currents at the same time. The two-channel version gives curve-trace capabilities.
As the first truly interactive measurement type application from Tektronix, it avoids having to write a program to, for example, do a full collector-voltage sweep or step the base current. The interactive graph includes a touch slider that changes the source value of the instrument, and it comes with user-friendly drop-down menus (Fig. 2).
The app is a good upgrade to what is essentially standard equipment, and will be useful to both expert and novice alike. Hoersten gave a good example of a keyboard make that was good at materials and keyboard mechanics, but didn’t understand enough about LED backlighting to figure out why the LEDs devices weren’t bright enough. Using the app, they quickly figured out that it was a drive-current issue: They were trying to drive all of the LEDs off a single 9-V battery and it couldn’t supply enough current. The app and SMU combination took away the pain of having to write the code to drive the devices.
Advanced users, on the other hand, might need to look quickly at a diode or FET device characteristics, checking for safe operating range, initial yields, and how the curves look in general, before completing the device design.
“Because we’re making it more accessible, our products become more usable,” says Hoersten. Good point.
The app takes full advantage of Apple and Android device interfaces, and gives simultaneous control over source levels and monitoring of test results. This makes it easy to visually analyze I-V characteristics, DUT stability, response time, or drift in a circuit using normal touch zooming and scrolling. The IVy app is compatible with Keithley Series 2600B SourceMeter SMUs running firmware version 3.1.0 or above, and joins three other Tektronix apps currently in the iTunes store:
• Tektronix Probe Finder
• Tektronix AFG2000 Intro
• International Frequency Allocations
All are informational, while the IVy stands out as being hands-on useful. Let us know what you think if you’ve already tried it.
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