Pulsed IV (current-voltage) measurements have emerged as the preferred method of capturing current-voltage characteristics of active devices such as field effect transistors (FET) and bipolar junction transistors (BJT). With the growing popularity of high power devices like GaN HEMTs and LDMOS devices, the current-voltage requirements are constantly being pushed higher and higher.
With these requirements in mind, Auriga Measurement Systems has developed its next generation Pulsed IV Measurement System, the AU4550. The AU4550 is designed to meet the ever-changing requirements of the device modeling community. With its modular hardware design and open software architecture, the AU4550 is poised to handle present and future pulsed IV requirements.Test Capabilities 
This new, high-end Pulsed IV Measurement System is a full-featured characterization platform capable of measuring DC IV curves, pulsed IV curves (see Figure 1), and expandable to pulsed S-parameters and model extraction. With pulse widths as fast as 200 ns and duty cycles as low as 0.01 percent, the AU4550 is ideally suited for isothermal testing of devices subject to the effects of self-heating. Unlike less capable competitive solutions, the AU4550 can deliver up to 200V at 10A, a must for designers working with high power devices. The AU4550 system has raised the bar for high power pulsed IV performance. Through the use of small external pulser heads, the pulser circuitry has been moved closer to the device under test (DUT), reducing the length of transmission lines from feet to mere inches. With the pulser circuitry moved closer to the DUT, the AU4550 preserves the integrity of the pulsed signal by reducing the effects of the transmission lines on the measurements. The external pulser heads are interchangeable and available in different configurations from 20V - 100mA to 200V - 10A with plans to go to 1200V and beyond.
Because the AU4550 measurement system is capable of capturing current-voltage vs. time, it delivers new ways of exploring the time-dependent effects, such as self-heating and carrier traps on devices. With the ability to move the measurement aperture across the top of the pulse, designers can see in real time the effects that self-heating and carriers have on the IV curves and better understand the impact they have on their device. With the addition of the optional S-parameter test set, the AU4550 becomes a full-featured pulsed IV/RF modeling system capable of meeting the most demanding requirements. The AU4550’s true wide bandwidth front-end allows it to measure pulsed S-parameters with RF pulse widths as fast as 100 ns with duty cycles as low as 0.01 percent while maintaining a dynamic range of greater than 90 dB.
The AU4550 can also be combined with and control other stand-alone network analyzers such as Agilent Technologies’ PNA-X. With its six-channel triggering subsystem the AU4550 can trigger external instruments to perform measurements synchronous with the DC pulse.
Modular Approach
The AU4550 system’s modular approach to both hardware and software guaranty a cost-effective upgrade path to address new measurement requirements as they arise. As analog-to-digital converters (ADC) advance, so does the AU4550. Its modular approach to hardware allows the internal ADCs to be upgraded with newer and faster ones as they become available. The external pulser heads allow the user to configure the system as needed—100V - 1A today and 200V - 10A tomorrow. The AU4550 can keep pace with the industry’s changing needs, protecting capital investment and improving return on investment.
Intuitive User Interface
The AU4550 offers the most advanced capabilities available in a fully integrated characterization system, including a complete embedded PC with the Windows XP operating system, mass storage and a writable CD. Although it satisfies virtually all requirements with regard to test capabilities and specifications, the intuitive user interface enables even inexperienced users to perform complex measurements quickly and easily. The integrated software and soft front-panel are easy to learn and use. All features are easily accessible on a touch screen and for those who prefer a keyboard, a mini keyboard with an integrated touch pad is provided. Figure 2 shows a typical pulse setup screen.
Conclusion
The new AU4550 Pulsed IV Measurement System is giving the modeling community something to be excited about. Users no longer have to fumble with racks of equipment, complicated wiring connections and internally developed software, only to generate questionable results. With its intuitive user interface and superior pulse performance, users are assured of clean accurate data the first time and every time. Additional information may be obtained via e-mail at sales@auriga-ms.com.
Auriga Measurement Systems LLC,
Lowell, MA (978) 441-1117,
RS No. 300