ACPL-C78A-500E (BROADCOM LIMITED)

The ACPL-C78A-500E is a 1-channel Miniature Isolation Amplifier designed for current sensing in electronic motor drives. In a typical implementation, motor currents flow through an external resistor and the resulting analogue voltage drop is sensed by the isolation amplifier. A differential output voltage is created on the other side of the isolation amplifier optical isolation barrier. This differential output voltage is proportional to the motor current and can be converted to a single-ended signal by using an op-amp. Since common-mode voltage swings of several hundred volts in tens of nanoseconds are common in modern switching inverter motor drives, this isolation amplifier is designed to ignore very high common-mode transient slew rates. The high CMR capability of the isolation amplifier provides the precision and stability needed to accurately monitor motor current in high noise motor control environments.