ISL32704E: Low-Cost Isolated RS-485 Transceiver

The ISL32704E is a galvanically isolated, differential bus transceiver designed for bidirectional data transmission and meeting the RS-485 and RS-422 standards for balanced communication. Each of the bus terminals, A and B, is protected against ±15kV ESD strikes without latch-up.

The device uses Giant Magnetoresistance (GMR) as isolation technology. A unique ceramic/polymer composite barrier provides excellent isolation and virtually unlimited barrier life.

The part is available in a 16 Ld QSOP package, offering unprecedented miniaturization.

The ISL32704E delivers a minimum differential output voltage of 1.5V into a 54Ω differential load for excellent data integrity over long cable lengths.

The device is compatible with 3V and 5V input supplies, allowing interface to standard microcontrollers without additional level shifting.

Current limiting and thermal shutdown features protect against output short circuits and bus contention that may cause excessive power dissipation. Receiver inputs feature a “fail-safe if open” design, ensuring a logic high R-output if A/B are floating.

Key Features
  • 4Mbps data rate
  • 2.5kVRMS isolation per UL 1577
  • 600VRMS working voltage per VDE 0884
  • 3V to 5V power supplies
  • Single unit load allows up to 32 devices on the bus
  • 50kV/μs (typical), 30kV/μs (minimum) common-mode transient immunity
  • 44000 years barrier life
  • 15kV ESD bus-pin protection
  • Low EMC footprint
  • Thermal shutdown protection
  • -40°C to +85°C temperature range
  • Meets or exceeds ANSI RS-485
  • 16 Ld QSOP package
  • UL 1577 recognized
  • VDE V0884-11 certification pending
Applications
  • Factory automation
  • Security networks
  • Building environmental control systems
  • Industrial/process control networks
  • Level translators (i.e., RS-232 to RS-485)
Typical DiagramProduct Image
Application Notes
TitleTypeUpdatedSizeOther Languages
AN1973: GMR Isolators in IEC61010-1 Edition 3 SystemsPDF02 May 201694 KB
AN1972: Giant-Magneto-Resistance as Digital Isolation TechnologyPDF02 May 2016155 KB
AN1971: GMR In IsolationPDF15 Apr 2016132 KB
Datasheets
TitleTypeUpdatedSizeOther Languages
ISL32704E DatasheetPDF10 Feb 2017382 KB
Design Files
TitleTypeUpdatedSizeOther Languages
ISL32704EVAL1Z Design FilesZIP10 Feb 2017375 KB
User Guides
TitleTypeUpdatedSizeOther Languages
ISL32704EVAL1Z User GuidePDF03 Jan 2017295 KB
White Papers
TitleTypeUpdatedSizeOther Languages
RS-485 Isolator Raises the Bar for Bus Node DesignsPDF29 Mar 2017423 KB
Order Information
Part NumberPackage TypeWeight(g)PinsMSL RatingPeak Temp (°C)RoHS Status
ISL32704EIAZ16 Ld QSOP0.08161260RoHS
ISL32704EIAZ-T7A16 Ld QSOP T+R0.08161260RoHS
ISL32704EVAL1ZN/ARoHS
ISL32704E Datasheet 10 Feb 2017
AN1973: GMR Isolators in IEC61010-1 Edition 3 Systems 02 May 2016
AN1972: Giant-Magneto-Resistance as Digital Isolation Technology 02 May 2016
AN1971: GMR In Isolation 15 Apr 2016
ISL32704EVAL1Z Design Files 10 Feb 2017
ISL32704EVAL1Z User Guide 03 Jan 2017
RS-485 Isolator Raises the Bar for Bus Node Designs 29 Mar 2017