5kVRMS Isolated 20Mbps Half-Duplex PROFIBUS DP/RS-485 Transceiver with ±35kV ESD Protection and Integrated Transformer Driver

Industry's Most Robust Isolated RS-485


The MAX14943 isolated RS-485/PROFIBUS DP transceiver provides 5000VRMS (60s) of galvanic isolation between the cable side (RS-485 driver/receiver side) and the UART side of the device. Isolation improves communication by breaking ground loops and reduces noise when there are large differences in ground potential between ports. This device allows for robust communication up to 20Mbps.

The device includes an integrated 450kHz transformer driver for power transfer to the cable side of the transceiver using an external transformer. An integrated LDO provides a simple and space-efficient architecture for providing power to the cable side of the IC.

The device includes one half-duplex driver/receiver channel. The receiver is 1/4-unit load, allowing up to 128 transceivers on a common bus.

Integrated true fail-safe circuitry ensures a logic-high on the receiver output when inputs are shorted or open. Undervoltage lockout disables the driver when cable-side or UART-side power supplies are below functional levels.

The driver outputs/receiver inputs are protected from ±35kV electrostatic discharge (ESD) to GNDB on the cable side, as specified by the Human Body Model (HBM).

The MAX14943 is available in a 16-pin wide-body SOIC package and operates over the -40°C to +105°C temperature range.

MAX14943: Functional Diagram MAX14943: Functional Diagram Enlarge+

Key Features

  • High Integration Simplifies Designs
    • Integrated LDO for Cable-Side Power
    • Integrated Transformer Driver for Power Transfer to Cable Side Has Up to 80% Efficiency at 150mA Load
  • High-Performance Transceiver Enables Flexible Designs
    • Compliant with RS-485 and EIA 61158-2 Type 3 PROFIBUS DP Standards
    • 20Mbps (max) Data Rate
    • Up to 128 Devices on the Bus
  • Integrated Protection for Robust Communication
    • ±35kV ESD (HBM) on Driver Outputs/Receiver Inputs
    • 5kVRMS Withstand Isolation Voltage for 60s (VISO)
    • 1200VPEAK Maximum Repetitive Peak-Isolation Voltage (VIORM)
    • 848VRMS Maximum Working-Isolation Voltage (VIOWM)
    • > 30 Years Lifetime at Rated Working Voltage
    • Withstands ±10kV Surge per IEC 61000-4-5
    • Thermal Shutdown


  • HVAC
  • Industrial Automation Equipment
  • Power Meters
  • Programmable Logic Controllers
Part Number Tx/Rx Duplex VSUPPLY
Galvanic Isolation
Data Rate
ESD Protect.
Rx/Tx on Bus Rx Failsafe w/ Inputs Slew Rate Limiting Oper. Temp.
Package/Pins Budgetary
typ min See Notes
MAX14943  1Tx + 1Rx Half 3.0 to 5.5 5000 4.7 20000 35 128 None No -40 to +105
$5.20 @1k
See All RS-485/RS-422 Line Driver/Receivers (182)
Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

MAX149X2EVKIT: Evaluation Kit for the MAX14940/MAX14943/MAX14946/MAX14949

Quality and Environmental Data

Request Reliability Report for: MAX14943 
Lead-Free Package Tin (Sn) Whisker Reports

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