The two instruments placed together are a testament to their respective eras. Tracing back to its origins, Tektronix introduced the industry's first curve tracer in 1955, displaying the characteristic curves of vacuum tubes. Since then, Tektronix has released more sophisticated and refined curve tracers for testing transistors, diodes, and other solid-state devices.
A curve tracer is a basic electronic test instrument that performs IV curve tracing by analyzing the characteristics of semiconductor devices (such as diodes, transistors, and thyristors). They are commonly used in device reliability applications, such as fault analysis and parameter characterization.
The Tektronix Type 576 curve tracer, introduced in 1969, has gained widespread industry recognition. The vintage TEK Antique Museum uses it for repairs in its restoration room.
Demand for classic curve trackers
Both in the past and present, these early models remain in high demand for fault analysis and educational applications. Their popularity stems in part from the fact that modern curve tracers cannot replicate simple interactive models, including the user experience of simply "turning a knob" to display a curve on the screen. Because these older Tektronix curve tracers are no longer in production, the continued demand has led to a robust market for used traditional curve tracers, with refurbished 370Bs fetching over $20,000 online.
For labs that prefer to continue using traditional curve tracers, this reliance on sophisticated, vintage equipment inevitably presents some obstacles. Given the cost of existing equipment, labs often have all failure analysis engineers share a single device. Running older equipment requires procuring and storing replacement components, which takes up considerable space in a limited lab environment. Furthermore, capturing and sharing data is not easy.
Modern IV curve tracking system configuration
Recognizing the market demand for instruments closer to the classic Tektronix curve tracer, Tektronix and Keithley launched two solutions. The first, the Keithley PCT (Parallel Curve Tracker Configuration), is an IV curve tracer configuration that includes everything characterization engineers need to develop a complete test system. Because these configurations are modular, they can be upgraded over time, with individual "building block" instruments, such as source measurement units, available for separate use in other applications when needed. While these configurations are the closest hardware equivalents to the classic curve tracer, their investment is also considerable. A simpler solution has now emerged to meet the needs of laboratories.
IV Curve Tracker Software
Keithley recently released IV curve tracer software, allowing fault analysis engineers to run tests that were previously performed by classic curve tracers for two-terminal devices using the Keithley SourceMeter™ Source Measurement Unit (SMU). Because the SMU can provide voltage or current while simultaneously measuring voltage and current, its hardware quality is identical to that of a curve tracer.
This newly released IV curve tracker software utilizes the intuitive touchscreen interface of the 2400 series graphical SMUs, recreating the familiar user experience of curve trackers for low-power two-terminal devices. The IV curve tracker software leverages the full functionality of its supported SMUs, including the dual high-speed digitizers of the 2461, to perform curve plotting functions, supporting AC polarity, pulsed DC, and standard DC polarity. For example, this corresponds to the 576, which has +DC, -DC, and AC polarity, and the output can be + voltage, - voltage, or both + and - voltage simultaneously.
Keithley IV Tracker software uses the touchscreen interface of the 2400 Series Graphical SMU, providing a familiar user experience for low-power two-terminal device reconstruction curve trackers.
Economic IV curve diagram
The lab no longer needs to pool resources and share outdated equipment; instead, each engineer can be equipped with their own IV curve tracer. Keithley SMUs are portable and can be easily placed on a test bench. Their size comparison with the 370B is immediately apparent in the opening image; the SMU with Keithley IV Tracer software is only a fraction of the size of a classic curve tracer. Furthermore, users still retain all the source, receiver, and measurement functions of the Keithley SMU, enabling curve tracer functionality with just a few clicks (or touches). Users can also easily export curves or screenshots without needing to search for spare parts online.
The Keithley IV tracker software, combined with SMU, offers an economical way to achieve the ease of use of a classic curve tracker without the burden of maintaining vintage instruments.
Application of IV Curve Tracker Software
IV curve tracers are popular for fault analysis of semiconductor devices, partly because they offer precise control and direct results. Excessive power supplied to a device can destroy sensitive evidence pointing directly to the root cause of a fault. IV curve tracers directly control the output level, simulating this function, allowing fault analysis (FA) engineers to slowly climb to an abnormal IV curve and then seamlessly delve into its behavior, supporting a minimum resolution of 500 nV (or 500 fA) on the source output.
Besides fault analysis, curve tracers have long been considered essential equipment for engineering education because they are very simple, allowing students to directly apply their knowledge to electrical devices. IV curve tracer software and SMU offer the same advantages, providing students with real-time direct control capabilities to experiment with and reinforce their knowledge of various electronic components.
If you're looking for the right solution for your application, try out our IV curve tracker configurations or learn more about Keithley IV curve tracker software and graphical SMUs.
