2600A AC Transimpedance Amplifier

Ultra-Precise AC Current Ratio Division

The MI 2600A provides ultra-precise ratio division of AC currents for the calibration of optical and non-conventional current transformers. Based on advanced current comparator technology, the 2600A delivers exceptional accuracy while simplifying the measurement process by automatically correcting for both magnitude and phase errors—without the need for manual adjustment controls.

The 2600A features two input current ranges, 1 A and 5 A, with seven selectable gain stages of 1, 2, 5, 10, 20, 50, and 100. These gain stages amplify low-current inputs while maintaining full-range accuracy. At a gain of 1, the full-scale input is 1 A or 5 A; at a gain of 100, full-scale inputs are reduced to 10 mA and 50 mA, respectively.

At the heart of the 2600A is a precision transimpedance amplifier—a current-to-voltage converter incorporating an input current transformer and precision resistive shunt. The resulting voltage is proportional to, and in phase with, the primary current, enabling ultra-precise AC current ratio measurements with accuracy of ≤20 ppm. Overall stability and accuracy are determined by the performance of the input current transformer and current comparator.

For applications requiring higher test currents, the 2600A can be combined with the MI 7020 Precision Current Transformer to extend current measurement capabilities up to 2000 A.

For long-term performance and measurement confidence, a calibration interval of 3 to 5 years is recommended.

Block Diagram Including 7020 Extender

^{* At 50 or 60 Hz}