LTC2859 - 20Mbps RS485 Transceiver with Integrated Switchable Termination

The LTC2859 and LTC2861 are low power, 20Mbps RS485/422 transceivers operating on 5V supplies. The receiver includes a logic-selectable 120Ω termination, one-eighth unit load supporting up to 256 nodes per bus, and a failsafe feature that guarantees a high output state under conditions of floating or shorted inputs.

The driver features a logic-selectable low-EMI 250kbps operating mode, and maintains a high output impedance over the entire common mode range when disabled or when the supply is removed. Excessive power dissipation caused by bus contention or a fault is prevented by current limiting all outputs and by a thermal shutdown.

Enhanced ESD protection allows the LTC2859 and LTC2861 to withstand ±15kV (human body model) on the transceiver interface pins without latchup or damage.

  • Integrated, Logic-Selectable 120Ω Termination Resistor
  • 20Mbps Max Data Rate
  • No Damage or Latchup to ESD: ±15kV HBM
  • High Input Impedance Supports 256 Nodes
  • 250kbps Low-EMI Mode
  • Guaranteed Failsafe Receiver Operation Over the Entire Common Mode Range
  • Current Limited Drivers and Thermal Shutdown
  • Delayed Micropower Shutdown (5μA Max)
  • Power Up/Down Glitch-Free Driver Outputs
  • Low Operating Current (900μA Max in Receive Mode)
  • Meets All TIA/EIA-485-A Specifi cations
  • Available in 10-Pin 3mm × 3mm DFN, 12-Pin 4mm × 3mm DFN and 16-Pin SSOP Packages
Typical Application
LTC2859 Typical Application
LTC2859 Typical Application
  • Low Power RS485/RS422 Transceiver
  • Level Translator
  • Backplane Transceiver
LTC2859 Package Drawing
LTC2859 Package Drawing
LTC2859 Package Drawing
Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LTC2859CDD#PBF3x3 DFN-10C$2.27$1.55
LTC2859CDD#TRPBF3x3 DFN-10C$1.61
LTC2859HDD#PBF3x3 DFN-10H$2.93$2.05
LTC2859HDD#TRPBF3x3 DFN-10H$2.11
LTC2859IDD#PBF3x3 DFN-10I$2.73$1.86
LTC2859IDD#TRPBF3x3 DFN-10I$1.92
Reliability Data
Product Selector Card
LT Journal
Press Release
Software and Simulation
CAD Symbol
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