ACPL-785J Isolation Amplifier with Short Circuit and Overload Detection

The ACPL-785J 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 ACPL-785J. A larger analog output voltage is created on the other side of the ACPL-785J’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 measure-ment 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 ACPL-785J was designed to ignore very high common-mode transient slew rates (10 kV/μs).

±3% gain tolerance part (HCPL-788J) is also available

 

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• Output Voltage Directly Compatible with A/D Converters (0 V to V_REF)
• Fast (3 μs) Short Circuit Detection with Transient Fault Rejection
• Absolute Value Signal Output for Overload Detection
• 1 μV/°C Offset Change vs. Temperature
• SO-16 Package
• –40°C to +85°C Operating Temperature Range
• 25 kV/μs Isolation Transient Immunity
• Regulatory Approvals: UL, CSA, IEC/EN/DIN EN 60747-5-5 (1230 Vpeak Working Voltage)
• Options:
  ACPL-785J-000E
  ACPL-785J-060E
  ACPL-785J-500E
  ACPL-785J-560E

• Inverter Current Sensing
• Switching Power Supply Signal Isolation
• Industrial A/D Converter
• Motor Phase and Rail Current Sensing
• General Purpose Current Sensing and Monitoring

• High common-mode rejection 25 kV/µs at V_CM = 1000 V provides precision and stability in high noise motor control environments
• ±5% gain tolerance provides accurate measurement in highly noisy motor control environments
• Advanced sigma-delta A/D converter technology ensures high precision
• Wide operating temperature range
• Integrated over-current and overload detection simplifies design

Data Sheets & Technical Specifications

• Data Sheet - ACPL-785J, Isolation Amplifier with Short Circuit and Overload Detection(220 KB,PDF)
• Options Data Sheet - Option 500 - Tape and Reel Packaging Option for Optocouplers(93 KB,PDF)
• Options Data Sheet - Shipping Tube Dimension for Optocouplers (Plastic/Solid State Relay)(141 KB,PDF)
• Selection Guide - Avago Technologies Optoisolation and Optical Sensor Products Selection Catalog(3008 KB,PDF)
• Selection Guide - Optoisolation Products Filo Selection Guide(1288 KB,PDF)
• White Paper - Automotive Isolation Amplifier for Voltage Sensing(132 KB,PDF)
• White Paper - Calculate the LED Lifetime Performance in Optocouplers to Predict Reliability(238 KB,PDF)

Application Notes

• Application Note - AN 1078; Designing with Avago Technologies Isolation Amplifiers(312 KB,PDF)
• Application Note - AN 1357; Overview of High Performance Analog Optocouplers(119 KB,PDF)
• Application Note - AN 5121 Isolation Amplifiers HallEffect Device For Motor Control Current Sensing Applications(227 KB,PDF)
• Application Note - AN 5431; Miniature Iso-Amp Rises to the Challenge of Sensing Motor Phase Current(540 KB,PDF)
• Application Note - AN 5476; Recommended Soldering Profile for Lead-Free Plastic Optocouplers and Solid State Relays(98 KB,PDF)

Design & Reference Guides

• Design Guide - Optocoupler Designer's Guide(577 KB,PDF)

Product Change Notices

• Product Changes Notice (PCN) - V11-001-32002150-0A(23 KB,PDF)
• Product Changes Notice (PCN) - V11-001-32002150-0B(23 KB,PDF)

Quality & Reliability

• Regulatory Certificate - Avago Regulatory Guide to Isolation Circuits(558 KB,PDF)