This part is a kind of semiconductor called ACPL-C784.

Function of this product has Miniature Isolation Amplifiers.

Manufacturers : AVAGO

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Some of the text within the PDF file :

ACPL-C78A, ACPL-C780, ACPL-C784 Miniature Isolation Amplifiers Data Sheet Description The ACPL-C78A/C780/C784 isolation amplifier family was 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 ACPL-C78A/C780/C784. A differential output voltage is created on the other side of the ACPL-C78A/ C780/C784 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 as shown in the recommended application circuit. Since common-mode voltage swings of several hundred volts in tens of nanoseconds are common in modern switching inverter motor drives, the ACPL-C78A [ ... ]

ACPL-C784 PDF Datasheet Download