The HCPL-788J isolation amplifier is designed for current sensing in electronic motor drives. In a typical implementation, motor currents flow through an external resistor and the resulting analog voltage drop is sensed by the HCPL-788J. A larger analog output voltage is created on the other side of the HCPL-788J"s optical isolation barrier. The output voltage is proportional to the motor current and can be connected directly to a single-supply A/D converter. A digital over-range output (FAULT) and an analog rectified output (ABSVAL) are also provided. The wire OR-able over-range output (FAULT) is useful for quick detection of short circuit conditions on any of the motor phases. The wire-OR-able rectified output (ABSVAL), simplifies measurement of motor load since it performs polyphase rectification. Since the common-mode voltage swings several hundred volts in tens of nanoseconds in modern electronic motor drives, the HCPL-788J was designed to ignore very high common-mode transient slew rates (10 kV/ms).
**HCPL-788J is on EBV"s motor control reference design.**
### Features
Output Voltage Directly Compatible with A/D Converters (0 V to VREF)
Fast (3 us) Short Circuit Detection with Transient Fault Rejection
Absolute Value Signal Output for Overload Detection
1 uV/ degrees C Offset Change vs. Temperature
SO-16 Package
-40 degrees C to 85 degrees C Operating Temperature Range
25 kV/us Isolation Transient Immunity
Regulatory Approvals: UL, CSA, IEC/EN/DIN EN 60747-5-2 (1230Vpeak Working Voltage)
