TIDA-01063: High Accuracy AC Current Measurement Reference Design using PCB Rogowski Coil Sensor

The TIDA-01063 is a reference design for current sensing using a PCB Rogowski coil sensor to achieve very good linearity for wide measurement range at a very low system BOM cost. The PCB Rogowski sensor is advantageous for isolated current measurement due to its very high bandwidth of 20 MHz and fast settling time of 50 ns. The auto-zeroing, 12-nV/(square root)Hz noise density of the INA188 makes it suitable to achieve a 12-bit system resolution for a full-scale current of 1000 A. Using a simple IIR digital integration algorithm and scalable sampling rate, it is possible to achieve better magnitude and phase response.

Design Features

• 0.058% Nonlinearity (Least Square Best Fit Straight Line)

• Very High Sensor Bandwidth of 20 MHz

• Uncalibrated Accuracy of 0.2%

• Theoretical Settling Time of 50 ns

• No Core Saturation

• Current Sensing for Multi-Conductor Using Single Sensor

• Low Footprint and BOM Cost

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