Features and Benefits

  • 2.5 kV fully isolated (power and data) RS-232 transceiver
  • isoPower integrated, isolated dc-to-dc converter
  • 460 kbps data rate
  • 1 Tx and 1 Rx
  • Meets EIA/TIA-232E specifications
  • ESD protection on RIN and TOUT pins
    • ±8 kV: contact discharge
    • ±15 kV: air gap discharge
  • 0.1 μF charge pump capacitors
  • High common-mode transient immunity: >25 kV/μs
  • Safety and regulatory approvals
    • UL recognition
      • 2500 V rms for 1 minute per UL 1577
    • VDE Certificate of Conformity (pending)
      • DIN EN 60747-5-2 (VDE 0884 Teil 2): 2003-01
    • CSA Component Acceptance Notice #5A (pending)
  • Operating temperature range: −40°C to +85°C
  • Wide body, 20-lead SOIC package

Product Details

The ADM3251E is a high speed, 2.5 kV fully isolated, single- channel RS-232/V.28 transceiver device that operates from a single 5 V power supply. Due to the high ESD protection on the RIN and TOUT pins, the device is ideally suited for operation in electrically harsh environments or where RS-232 cables are frequently being plugged and unplugged.

The ADM3251E incorporates dual-channel digital isolators with isoPower™ integrated, isolated power. There is no requirement to use a separate isolated dc-to-dc converter. Chip-scale transformer iCoupler® technology from Analog Devices, Inc., is used both for the isolation of the logic signals as well as for the integrated dc-to-dc converter. The result is a total isolation solution.

The ADM3251E contains isoPower technology that uses high frequency switching elements to transfer power through the transformer. Special care must be taken during printed circuit board (PCB) layout to meet emissions standards. Refer to Application Note AN-0971, Control of Radiated Emissions with isoPower Devices, for details on board layout considerations. The ADM3251E conforms to the EIA/TIA-232E and ITU-T V. 28 specifications and operates at data rates up to 460 kbps. Four external 0.1 μF charge pump capacitors are used for the voltage doubler/inverter, permitting operation from a single 5 V supply.

The ADM3251E is available in a 20-lead, wide body SOIC package and is specified over the −40°C to +85°C temperature range.


  • High noise data communications
  • Industrial communications
  • General-purpose RS-232 data links
  • Industrial/telecommunications diagnostic ports
  • Medical equipment

Product Lifecycle icon-recommended Production

At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.

Evaluation Kits (1)

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ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well.  "Zero defects" for shipped products is always our goal.

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Up to two boards can be purchased through Analog.com. To order more than two, please purchase through one of our listed distributors.

Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.