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2.75kVRMS Isolated 20Mbps Half-Duplex PROFIBUS/RS-485 Transceiver with ±35kV ESD Protection and Integrated Transformer Driver

Industry's Most Robust Isolated RS-485

Product Details

Key Features

Parametric specs for RS-485/RS-422 Line Driver/Receivers
# Tx/Rx 1Tx + 1Rx
Duplex Half
VSUPPLY (V) 3.0 to 5.5
Data Rate (kbps) (min) 20000
Galvanic Isolation (±V) 2750
ICC (mA) (typ) 4.7
ESD Protect. (±kV) 35
Tx EN Yes
Rx EN Yes
Oper. Temp. (°C) -40 to +105
Package/Pins SOIC HYBRID (W)/16
Budgetary
Price (See Notes)
4.68
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Simplified Block Diagram

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Parameters

Parametric specs for RS-485/RS-422 Line Driver/Receivers
# Tx/Rx 1Tx + 1Rx
Duplex Half
VSUPPLY (V) 3.0 to 5.5
Data Rate (kbps) (min) 20000
Galvanic Isolation (±V) 2750
ICC (mA) (typ) 4.7
ESD Protect. (±kV) 35
Tx EN Yes
Rx EN Yes
Oper. Temp. (°C) -40 to +105
Package/Pins SOIC HYBRID (W)/16
Budgetary
Price (See Notes)
4.68

Key Features

  • High Integration Simplifies Designs
    • Integrated LDO for Cable-Side Power Can Also Power External Loads Up to 10mA
    • 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 EIA/TIA-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
    • 2.75kVRMS Withstand Isolation Voltage for 60 Seconds (VISO)
    • 630VPEAK Maximum Repetitive Peak Isolation Voltage (VIORM)
    • 445VRMS Maximum Working Isolation Voltage (VIOWM)
    • > 30 Years Lifetime at Rated Working Voltage
    • Withstands ±10kV Surge per IEC 61000-4-5
    • Thermal Shutdown

Applications/Uses

  • HVAC
  • Industrial Automation Equipment
  • Power Meters
  • Programmable Logic Controllers

Description

The MAX14940 isolated RS-485/PROFIBUS-DP transceiver provides 2750VRMS (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 reduced noise when there are large differences in ground potential between ports. This device allows for robust communication up to 20Mbps.

The MAX14940 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 way of designing an isolated DC/DC supply.

The MAX14940 includes one half-duplex driver/receiver channel that is fully compliant with both RS-485 and PROFIBUS-DP standards. 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 MAX14940 is available in a wide body 16-pin SOIC package and operates over the -40°C to +105°C temperature range.

Simplified Block Diagram

MAX14940: Functional Diagram MAX14940: Functional Diagram Zoom icon

Technical Docs

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .