Oscilloscope News

Tektronix IsoVu18 March 2016 – Tektronix announced that it will be previewing its new IsoVu technology at the APEC 2016 show that will offer complete galvanic isolation between a device under test (DUT) and an oscilloscope through the use of electro-optical sensors. It will be the industry’s first measurement solution capable of accurately resolving high bandwidth differential signals in the presence of large common mode voltage. The technology will also offer immunity to external interference and radiated emissions, minimizing the impact of EMI on measurements.

To date, design engineers working on power device designs involving GaN and SiC technologies and other high-speed applications have had no way to accurately visualize differential signals when common mode interference is present. As a result, these signals are essentially hidden, making it difficult for engineers to see what is actually occurring inside circuits, slowing debug and characterization efforts. Engineers also face challenges making measurements in noisy environments or those that have high EMI.

The IsoVu technology being shown at APEC has the potential to resolve these challenges. It utilizes an electro-optic sensor to convert the input signal to optical modulation, which electrically isolates the device-under-test from the oscilloscope. IsoVu will incorporate four separate lasers, an optical sensor, five optical fibers, and sophisticated feedback and control techniques. The sensor head, which connects to the test point, has complete electrical isolation and is powered over one of the optical fibers. Ten patent disclosures have been filed for this technology.

“This is an outstanding example of the type of innovative thinking that drives us at Tektronix to tackle difficult problems that have never been resolved in the past,” said Earl Thompson, senior vice president, Time Domain Business Unit, Tektronix. “There’s no getting around the fact that an electrical connection between the oscilloscope and the device under test impacts measurement results. By moving to an optical connection, this technology has the potential to eliminate that as a problem and as a result could significantly advance the state-of-the-art in power measurement and EMI test systems.”

As demonstrated, IsoVu technology offers greater than 120 dB (1 Million:1) common mode rejection from DC to 100 MHz which is 33,000 times better than previously available measurement systems. At 1 GHz, it will provide 80 dB (10,000:1) common mode rejection at 1 GHz, which is more than a thousand times better than previously available measurement systems. As a result, users will be able to measure anywhere in their circuit without common mode interference.

Using this technology, engineers will be able to accurately measure small differential signals (5 mV - 50 V) in the presence of large common mode voltages less than 2 kV from DC to 1 GHz. This will be the first signal acquisition product where the common mode voltage capability does not de-rate over bandwidth.

Adding to its versatility, Tektronix plans to offer a 10 meter fiber optic cable option with the same performance specifications as the 3 meter option to allow users to move their test system away from the interference and radiated emissions of the device under test. As such, it will be well-suited for such applications as remote testing and EMI validation.

APEC is the premier event for applied power electronics, focusing on the practical and applied aspects of the power electronics business. Tektronix will be showing IsoVu technology along with its full range of power measurement solutions in Booth #1061.


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