Isolation Amplifier with Short Circuit and Overload Detection

Currently Viewing:

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.


  • 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)
  • Options available are:
500 = Tape and Reel Packaging, 850
XXXE = Lead Free Option


  • Automatic Meter Reading(AMR)
  • Powerline Modem
  • Home Automation / Control
  • Security and Surveillance
  • General Purpose Isolated Transceiver
  • Internet Appliances

Lifecycle Status


Substance Compliance

  • RoHS
    Pb & Pb-free options available
Specification Value
Lifecycle Active
Distrib. Inventory Yes
RoHS6 Compliant Pb & Pb-free options available
Product Type Miniature Isolation Amplifier
Package S016
Operating Temperature Deg C -40 to +85
Gain Error at 25 Deg C (%) Max ±3
VDD2 (V) 4.5 - 5.5
CMR (min.) (V/µs) 25000.0
Vcm (V) 1000.0
UL Insulation Rating Viso (VRMS) 5000.0
IEC Maximum Working Insulation Voltage Viorm (VPEAK) 1230.0
IEC Highest Allowable Overvoltage Viotm (VPEAK) 8000
Application Brief1 i
Application Note13 i
Brochures3 i
Design Guide1 i
FAQs2 i
Obsolescence Notice1 i
Options Data Sheet6 i
Product Change Notice (PCN)16 i
Regulatory Certificate2 i
Reliability Data Sheet2 i
Selection Guide2 i
White Papers5 i
Promotional Material1 i