Broadcom Limited ACPL-C79B/C79A/C790 isolation amplifiers were designed for current and voltage sensing in electronic power converters in applications including motor drives and renewable energy systems. In a typical motor drive implementation, current flows through an external resistor and the resulting analog voltage drop is sensed by the isolation amplifier. A differential output voltage that is proportional to the current is created on the other side of the optical isolation barrier.
For general applications, the ACPL-C79A (±1% gain tolerance) and the ACPL-C790 (±3% gain tolerance) are recommended. For high precision applications, the ACPL-C79B (±0.5% gain tolerance) can be used. The product operates from a single 5 V supply and provides excellent linearity and dynamic performance of 60 dB SNR. With 200 kHz bandwidth, 1.6 µs fast response time, the product captures transients in short circuit and overload conditions. The high common-mode transient immunity (15 kV/µs) of the ACPL-C79B/C79A/C790 provides the precision and stability needed to accurately monitor motor current in high noise motor control environments, providing for smoother control (less "torque ripple") in various types of motor control applications.