Tektronix’ isolated probe system now measures large differential voltages
IsoVu, introduced in 2016, features 120 dB (1 million-to-1) common mode rejection. Tektronix is now adding new products to its IsoVu portfolio with a large differential voltage range and a higher input impedance.
With six new models, the IsoVu family portfolio now includes products with both large differential and common mode voltage ranges. Users can now accurately measure a wide range of differential signals (5 mV to > 1,000 V) from DC to 800 MHz in the presence of large common mode voltages up to 60 kV.
The new IsoVu products also include high input impedance. The differential input resistance is up to 40 MΩ and the differential input capacitance can be as low as 2 pF. A large input impedance allows users to make measurements anywhere in their circuit without concerns about loading the signal under test. The combination of large differential voltage and high input impedance allows designers to completely characterize their systems and eliminates the need for conventional probes tied back to ground through the scope.
New IsoVu models with these capabilities are available with 200 MHz, 500 MHz, 800 MHz bandwidths 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 allow users to move their test system away from the interference and radiated emissions of the device under test. The previous 1 GHz model continues to be available.
Typically, as in this commentary from Panasonic Semiconductor, users employ the system to see detail within a very large base signal level; “We needed a way to isolate the common mode voltages from the differential signals we were interested in. With IsoVu, we can now directly observe the gate voltage waveforms without adverse effects on the circuit. This is truly revolutionary.”
Efficient Power Conversion Corp. (EPC), a provider of GaN-based power management technology, also struggled to make direct measurements on signals when common mode interference was present. “The high bandwidth and high isolation voltage capability of the Tektronix IsoVu Probe is a tremendous tool, aiding in accurate verification of various EPC eGaN FET based high side gate driver power supply designs… EPC has decided to include IsoVu compatible connections on all new development boards such as the EPC9063 and many more. And now with IsoVu’s large differential voltage range and high input impedance, this will open up even more measurement capability. “
The updated IsoVu models will be delivered from late Q3, 2017.
Tektronix; www.tek.com
