How to Select Shunt Resistors for High Bandwidth Oscilloscope Current Measurements

Shunt resistors are widely used for high-bandwidth current measurements where low inductance and accurate signal capture are required. Careful selection is necessary to balance electrical performance, thermal constraints, and measurement fidelity in fast-switching and high dynamic range applications.

This application note:

• Presents a systematic approach to selecting shunt resistors, including current range, resistance value, power dissipation, bandwidth, and test point implementation.
• Explains the trade-offs between signal-to-noise ratio, burden voltage, and thermal limits when optimizing measurement performance.
• Describes how parasitic inductance and resistor form factor impact bandwidth and measurement accuracy.
• Provides examples of shunt technologies and guidance for selecting appropriate values for high-bandwidth oscilloscope-based measurements.