The IsoVu measurement system form Tektronix combines wide common mode range, 120dB common mode rejection and 1GHz bandwidth, enabling previously hidden signals to be made visible.

The platform uses an electro-optic sensor to convert input signals to optical modulation, electrically isolating the device-under-test from a Tektronix oscilloscope. The system incorporates four separate lasers, an optical sensor, five optical fibres, 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 fibres. Ten patent applications have been filed for this ground breaking technology.

 
EDNA tektronix 660x550 Figure 1: Ten patent applications have been filed for this ground breaking technology.  

A critical advantage this technology offers for designers, such as those working on power devices involving GaN and SiC technologies, is superior common mode rejection that makes signals previously buried in common mode noise visible for the first time. IsoVu offers 1,000,000:1 (120dB) common mode rejection (CMRR) up to 100MHz and 10,000:1 (80dB) CMRR at 1GHz. By comparison, competitive systems at 100MHz offer approximately 20dB CMRR at 100MHz, making IsoVu 100,000 times better.

"The feedback we received from designers at APEC was overwhelmingly positive, with many of them facing a critical need for the design insights IsoVu now makes possible," said Chris Witt, general manager, Time Domain Business Unit, Tektronix. "Currently there is no measurement system on the market with IsoVu's combination of high bandwidth, 2000V common mode voltage range and breakthrough common mode rejection ratio."

Using IsoVu, engineers can accurately measure small differential signals (5mV-50V) in the presence of large common mode voltages from DC to 1GHz. IsoVu is the first signal acquisition product where the common mode voltage capability does not de-rate over bandwidth. IsoVu technology is available in 6 models of the TIVM Series Isolated Measurement Systems with 200MHz, 500MHz and 1GHz bandwidth configurations with either 3-metre or 10-metre fibre optic cable lengths.

The 10-metre cable option offers the same performance specifications as the 3-metre option and allows users to move their test system away from the interference and radiated emissions of the device under test. With this option, IsoVu is well-suited for such applications as remote testing and EMI validation.