DRV421 Closed-Loop Current Sensing IC Texas Instruments DRV421 Closed-Loop Current Sensing IC is designed for magnetic closed-loop current sensing solutions. This enables isolated, precise dc- and ac-current measurements. This provides both, a proprietary integrated fluxgate sensor, and the required analog signal conditioning, thus minimizing component count and cost. The low offset and drift of the fluxgate sensor, along with an optimized front-end circuit results in unrivaled measurement precision. This device provides all the necessary circuit blocks to drive the current-sensing feedback loop. The sensor front-end circuit is followed by a filter that can be configured to work with a wide range of magnetic cores. The integrated 250mA H-Bridge drives the compensation coil while doubling the current measurement range, compared to conventional single-ended drive methods. The device also provides a precision voltage reference and shunt sense amplifier. This allows the device to generate and drive the analog output signal.