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5kVRMS Isolated 500kbps/25Mbps Full-Duplex RS-485/RS-422 Transceivers 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 Full
VSUPPLY (V) 3.0 to 5.5
Data Rate (kbps) (min) 25000
Galvanic Isolation (±V) 5000
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)
5.01
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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 Full
VSUPPLY (V) 3.0 to 5.5
Data Rate (kbps) (min) 25000
Galvanic Isolation (±V) 5000
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)
5.01

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 EIA/TIA-485 Standard
    • 500kbps (MAX14857)/25Mbps (MAX14859) Maximum 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 60 Seconds (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

Applications/Uses

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

Description

The MAX14857/MAX14859 isolated RS-485/RS-422 transceivers provide 5000VRMS (60s) of galvanic isolation between the cable-side (RS-485/RS-422 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. These devices allow for robust communication up to 500kbps (MAX14857) or 25Mbps (MAX14859).

The devices include 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 devices include one drive channel and one receive channel. The receiver is ¼-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 and receiver inputs are protected from ±35kV electrostatic discharge (ESD) to GNDB on the cable-side, as specified by the Human Body Model (HBM).

The MAX14857/MAX14859 are available in a wide body 16-pin SOIC package and operate over the -40°C to +105°C temperature range.

Simplified Block Diagram

MAX14857, MAX14859: Functional Diagram MAX14857, MAX14859: 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 .