This inductive current shunt enables current measurements of very high bandwidth, in the range 160 kHz-500 MHz. It is available with a range of full-scale measuring ranges of extending up to ±250A. It introduces essentially zero resistance into the measured current path, and inductance of only 300 pH.
The measurement shunt is a product of Fraunhofer Institute for Reliability and Microintegration IZM, in Berlin. You might use it for precision measurement of any current, particularly large currents that are subject to high-speed transients, in power electronics. A specific application is characterising the switching behaviour of high-speed power semiconductor devices, such as the latest silicon carbide and gallium nitride parts.
It is an active, inductive current shunt. The pictures show how the “primary” coil – a slotted cylinder forming a single turn – is soldered to bridge a gap in a wide PCB conductor. A Rogowski coil sits within the cylindrical element, and the signal processing within the probe carries out integration to produce the signal that you can then view with a conventional oscilloscope connection.
As a metallic, slotted cylinder, shunt resistance is negligible and inductance added to the measured-current path is 300 pH. Peak voltage isolation is up to 5 kV; slew rate is 5.5 V/nsec; power supply is 5Vdc and the probe outputs a full-scale ±0.8V signal to a scope from an SMB connection, for termination into a 50Ω input. The measurement is made at high impedance to minimise any influence on the measured current.