Customers Seek Optimum Price Points
Although engineers value flexibility and room to grow in their instruments, economic realities are dictating that they seek out optimum price points when purchasing new equipment. That’s the conclusion of Jerry Janesch, market development manager for multi-application products at Keithley Instruments, who has been examining customer requirements in the planning of product development at the company.
“Customers are buying just what they need today,” he said. “They’re asking, ‘Why should I pay for capabilities I won’t use?’” Nevertheless, he said, they value instrument/system flexibility and want to be able to reuse, repurpose, and redeploy their test-and-measurement hardware and software. Further, Janesch said, customers want quick results—they want instruments that are easy to use and offer high throughput.
Janesch’s observations have guided Keithley in its development of several products that it has introduced over the past few months. Those products include three SMUs (source-measure units), a 5½-digit dual-display DMM, two multichannel DC programmable power supplies, a dual-channel picoammeter/voltage source, and a series of instruments that combine curve tracer and parametric analyzer functionality.
Janesch said the new Series 2600B SourceMeter SMUs embody several features that support ease of use as well as reuse (Figure 1). The instruments offer Model 2400 software-command emulation to protect customers’ investment in software written for the older instrument. In addition, the new instruments feature full backward-compatibility with the Series 2600A instruments, offering a browser-backed GUI via embedded plug-and-play test software while supporting Keithley’s Test Script Processor (TSP) technology to achieve high measurement speeds as well as the company’s TSP-Link technology to enable multichannel parallel test.
Janesch emphasized, “Full software emulation of the Model 2400 allows for easier upgrade to Series 2600B-level performance” while providing a migration path from SCPI programming to TSP technology. The new models, he said, are designed for R&D, teaching, and other applications for which precision measurements are important but leading-edge test automation is not. Prices range from $6,000 for a single-channel 40-V, 3-A-DC/10-A-pulse version offering 100-fA resolution to $13,700 for a dual-channel 200-V, 1.5-A-DC/10-A-pulse version offering 0.1-fA resolution.
Speed is a key benefit of the new Model 2110 DMM, Janesch said, adding that the unit, capable of taking 50k readings per second at 0.012% DCV accuracy, is 10 times faster and twice as accurate as a competitive model. The instrument, he said, offers flexibility for bench and automation applications, and it can display two measurements concurrently: for example, DCV and temperature. The instrument comes with software that supports data export to a PC. The customer, who can use the instrument to make a few measurements quickly, needs no additional software or programming skills to access measurement data, Janesch said. A USB version costs $595; a version that adds GPIB costs $725.
Programmable DC Supplies
Efforts to achieve accuracy and versatility were behind Keithley’s development of the Series 2200 multichannel power supplies, Janesch said. The $950 Model 2220-30-1 supply provides two output channels, each capable of outputting up to 30 V at 1.5 A (45 W). The $1,150 Model 2230-30-1 offers the same two 45-W output channels, typically used for powering analog circuits, plus a 6-V at 5-A (30-W) output channel, usually used for powering digital circuits.
Janesch noted that the supplies feature an independent display for each channel, channels can be turned on and off independently, and the instrument offers remote-sense inputs on all channels. Further, all outputs are isolated, and channels can be connected in series or parallel, with the displays adapting to automatically display, for example, the correct voltage level for two channels connected in series.
Low-Current Measurement
In addition, Janesch said, Keithley has expanded its low-level-measurement product offerings by introducing the Model 6482 dual-channel picoammeter, which features dual ±30-V independent, nonfloating bias sources and 1-fA measurement resolution (Figure 2). The $3,600 picoammeter’s two independent picoammeter/source channels fit within a 2U half-rack enclosure, allowing simultaneous 6½-digit measurements across both channels while conserving rack or bench space.
Janesch said the instrument supports ratio and delta measurements, displaying the proportional or difference relationships between two measurement channels, thereby making it easy for users to compare device outputs or the responses from multiple sensors or detectors simultaneously. In addition, Janesch said, the picoammeter can measure currents up to 20 mA while maintaining 1-fA resolution, supporting applications involving dual-diode testing, dark current measurements, ion-beam monitoring, nanoscience, materials and semiconductor research, and electron microscopy.
Curve Tracer and Parametric Analyzer
Finally, Keithley debuted seven instrumentation, software, and test-fixture configurations for parametric curve-tracing applications for characterizing high-power devices at up to 3,000 V and 100 A, including devices based on silicon carbide (SiC) and gallium nitride (GaN) technology (Figure 3).
Lee Stauffer, a Keithley staff technologist, noted, “Many power device developers have told us they like the dynamic range and ease of use of a traditional curve tracer, but they know they need more flexibility in configuring the measurement channels as well as the accuracy, capability, and graphical user interface that a modern parametric analyzer offers.” He said that, in contrast with solutions that require all instrumentation to be housed in a chassis, the seven Keithley configurations can be repurposed. They offer the flexibility to add measurement channels economically as users’ needs evolve, with no need to return the system to the factory to install new hardware. For example, he said, someone could start with an entry-level parametric curve tracer and then add the capabilities of more System SourceMeter instruments, such as higher voltage and/or higher current, at a later date.
Six different System SourceMeter instrument models can be mixed and matched to create the optimum combination of voltage, current, and power for specific needs. Keithley’s TSP-Link virtual backplane technology makes it easy to incorporate any number of source-measure channels, all of which are fully and automatically synchronized with other SourceMeter instruments in the system.
All seven configurations include the latest version of Keithley’s Automated Characterization Suite (ACS) Basic Edition software, which supports the company’s newest SMUs and takes maximum advantage of the Series 2600B’s TSP-Link connection trigger model, which allows for 500-ns trigger synchronization between instruments. This tighter synchronization capability maximizes the high-speed pulse mode capabilities of the new Model 2651A and Model
2657A high-power System SourceMeter instruments.
For Further Reading
- Overview of Two-Wire and Four-Wire (Kelvin) Resistance Measurements, Keithley Instruments, Application Note Number 3176, 2012.
- Using the Dual Measurement Functionality and Dual Measurement Display on the Keithley Model 2110 5½-Digit Dual-Display Digital Multimeter, Keithley Instruments, Application Note Number 3168, 2012.
- Achieving High Reading Rates Using the Data Buffer on the Keithley Model 2110 5½-Digit Dual-Display Digital Multimeter, Keithley Instruments, Application Note Number 3167, 2012.
- Making Temperature Measurements with the Keithley Model 2110 5½-Digit Dual-Display Digital Multimeter (DMM), Keithley Instruments, Application Note Number 3175, 2012.
- Ensuring that Power Supply Performance Meets Your Requirements, Keithley Instruments, Application Note Number 3185, 2012.
- Understanding Linear Power Supply Specifications, Keithley Instruments, Application Note Number 3137, 2012.
- Low Current Measurements, Keithley Instruments, Application Note Number 1671, 2012.