IsoVu Isolated Probes

What is an Isolated Probe?

An Isolated probe uses galvanic (optical) or RF isolation to divorce the reference voltage of the probe from the reference voltage of the oscilloscope (typically Earth Ground). This enables power designers to accurately resolve high bandwidth, high voltage differential signals in the presence of large common mode voltages. Tektronix has developed a new technology (IsoVu) that uses galvanic isolation to provide best in class common mode rejection performance across a wide bandwidth.

The combination of isolation and high frequency in IsoVu probes provide power designers with more accurate measurements than traditional differential probes for applications that require high bandwidth while measuring high voltage signals. Example use cases include:

• Switched Mode Power Supply design
• Power FET design/analysis for Wide Bandgap GaN and SiC devices
• Inverter design
• Motor Drive design
• BCI or ESD measurements
• Current shunt measurements

Less Common Mode Noise, More Detail

IsoVu technology uses power-over-fiber and an optical analog signal path for complete galvanic isolation between the measurement system and your DUT. By allowing the probe to float independently at the common mode voltage, isolation greatly reduces common mode interference.

In combination with a 4, 5 or 6 Series MSO, IsoVu provides an efficient, reliable way to resolve high-bandwidth differential signals with fast-slewing references, allowing you to spend less time “designing blind” in a variety of situations:

• Floating measurements in power supplies
• Measuring current through shunt resistors
• Debugging ESD and EMI susceptibility problems
• Breaking ground loops

High Differential Voltage at a Range of Bandwidths

With traditional differential probes you had to choose between high bandwidth or high voltage levels. IsoVu probes, with their shielded coaxial cable and isolation, provide high bandwidth and a differential voltage range of ±2500V.

IsoVu Gen 2 offers a range of bandwidths – 200 MHz, 500 MHz, and 1 GHz – to fit your budget and build your bench with the performance necessary for your specific projects.

 

Innovative Technology in a Space-Saving Design

IsoVu Generation 2 probes offer the same bandwidth, common mode rejection, and voltage range as our original IsoVu probes, but at 1/5 of the size and without a separate controller box. The lasers and analog electronics are contained in the compact head and oscilloscope connector. Compared to our original IsoVu probes, Generation 2 probes also have:

• Better DC gain accuracy
• Improved step response
• More built-in ranges

High Performance with Convenient Connections

IsoVu probe tips have a range of connections and accessories that offer high performance and accessibility.

For example, MMCX connectors are inexpensive, widely available connectors that make for stable, hands-free test points and offer the best bandwidth and common mode rejection. Their solid metal body shields the center conductor and minimizes ground loop area for the lowest interference possible.

Other accessories are available to adapt the probe tips to a wide range of connections. Additional 0.100” and 0.200” spaced square-pin tips are available for applications that require greater than ±250V differential voltage.

When not using a tip, the sensor head has 1 M? and 50 ? switchable termination at the probe’s SMA connector. This feature effectively adds an isolated channel to any compatible oscilloscope.

• Wide Bandgap Power Device Testing: Accurately measure high-speed switching in SiC and GaN-based systems without signal distortion.

• High-Side Gate Drive Measurements: Safely capture signals in floating or high-voltage reference environments, including motor drives and inverters.

• Power Converter and Inverter Design: Perform differential measurements in noisy environments with superior CMRR and low noise.

• EMI and Noise Diagnostics: Troubleshoot signal integrity and ground loop issues in complex PCB layouts and power systems.

• Automotive and EV Systems: Analyze fast-switching, high-voltage circuits in electric drivetrain and power distribution applications.

• Aerospace and Defense Electronics: Ensure accurate validation of avionics, radar, and high-voltage control systems under harsh conditions.

• Embedded System Debugging: Observe isolated control signals or floating nodes in digital and mixed-signal designs.

Debugging ESD Issues

Going beyond functional testing to troubleshoot the root cause of ESD failures can be frustrating. When using conventional electrical probes, the ESD discharge couples into the probe and propagates down the cable to the oscilloscope, even if the scope is sitting outside of a faraday cage. Any waveform visible on the scope isn’t representative of what’s actually happening at the test point. But thanks to optical isolation, IsoVu Gen 2 probes prevent coupling and give a more accurate picture of DUT behavior during ESD and EFT testing beyond simple system testing.

Measuring Current Through Shunt Resistors

Measuring the differential voltage across a shunt resistor should be an easy way to get accurate current measurements. But due to the common mode voltages involved, it can be surprisingly challenging. IsoVu, with its high common mode voltage rating and high common mode rejection, succeeds where others fail.

Debugging ESD Issues

Going beyond functional testing to troubleshoot the root cause of ESD failures can be frustrating. When using conventional electrical probes, the ESD discharge couples into the probe and propagates down the cable to the oscilloscope, even if the scope is sitting outside of a faraday cage. Any waveform visible on the scope isn’t representative of what’s actually happening at the test point. But thanks to optical isolation, IsoVu Gen 2 probes prevent coupling and give a more accurate picture of DUT behavior during ESD and EFT testing beyond simple system testing.

 

The measurement system can be used with the following Tektronix oscilloscopes. Oscilloscope software version 1.28 or higher is required. For oscilloscopes not included in this list, contact your local Tektronix representative.

• 4 Series MSO Mixed Signal Oscilloscope
• 5 Series MSO Mixed Signal Oscilloscope
• 5 Series MSO Low Profile
• 6 Series MSO Mixed Signal Oscilloscope

• Optical Isolation for Maximum Signal Fidelity: Complete galvanic isolation between probe and oscilloscope eliminates ground loops and minimizes noise.

• Exceptional Common-Mode Rejection (CMRR): Maintains high accuracy in noisy environments with up to 160 dB CMRR at 100 MHz.

• Wide Bandwidth Range: Supports bandwidths from DC up to 1 GHz for capturing fast-switching signals in modern power designs.

• High Differential Voltage Measurement: Measures differential voltages up to ±2500 V, ideal for SiC/GaN-based high-side gate drives and power converters.

• Precision Across Temperature and Frequency: Delivers stable, repeatable results across changing thermal and signal conditions.

• Compact, Remote Head Design: Allows probing in tight spaces without introducing mechanical stress or signal distortion.

• Oscilloscope Compatibility: Seamlessly integrates with Tektronix scopes via the TekVPI™ interface for full probe control and calibration.

Parameter	Value
Bandwidth	DC to 200 MHz / 500 MHz / 1 GHz (model dependent)
CMRR	Up to 160 dB at 100 MHz
Differential Voltage Range	±50 V to ±2500 V
Input Capacitance	≤ 3 pF
System Noise (typical)	< 1.5 mVrms (depending on bandwidth and gain setting)
Propagation Delay	< 25 ns
Working Common Mode Voltage	±60 kV peak (model dependent)
Probe Interface	TekVPI™
Cable Length	3 m (standard), extendable with optical cable
Operating Temperature Range	0 °C to +50 °C
Power Supply	Powered via probe interface (no external supply needed)