LTC2870 - RS232/RS485 Multiprotocol Transceivers with Integrated Termination

Features

  • One RS485 and Two RS232 Transceivers
  • 3V to 5.5V Supply Voltage
  • 20Mbps RS485 and 500kbps RS232
  • Automatic Selection of Integrated RS485 (120Ω) and RS232 (5kΩ)Termination Resistors
  • Half-/Full-Duplex RS485 Switching
  • High ESD: ±26kV (LTC2870), ±16kV (LTC2871)
  • Logic Loopback Mode
  • 1.7V to 5.5V Logic Interface
  • Supports Up to 256 RS485 Nodes
  • RS485 Receiver Failsafe Eliminates UART Lockup
  • H-Grade Available (–40°C to 125°C)
  • Available in 28-Pin 4mm × 5mm QFN and TSSOP (LTC2870), and 38-Pin 5mm × 7mm QFN and TSSOP (LTC2871)
Designed for Automotive and Transportation Applications
AEC-Q100 generic family data available for specific packages


Typical Application

LTC2870 Typical Application
LTC2870 Typical Application
LTC2870 Typical Application

Description

The LTC®2870/LTC2871 are robust pin-configurable multiprotocol transceivers, supporting RS232, RS485, and RS422 protocols, operating on a single 3V to 5.5V supply. The LTC2870 can be configured as two RS232 single-ended transceivers or one RS485 differential transceiver on shared I/O lines. The LTC2871 offers independent control of two RS232 transceivers and one RS485 transceiver, each on dedicated I/O lines.

Pin-controlled integrated termination resistors allow for easy interface reconfiguration, eliminating external resistors and control relays. Half-duplex switches allow four-wire and two-wire RS485 configurations. Loopback mode steers the driver inputs to the receiver outputs for diagnostic self-test.The RS485 receivers support up to 256 nodes per bus, and feature full failsafe operation for floating, shorted or terminated inputs.

An integrated DC/DC boost converter uses a tiny 2mm × 1.6mm inductor and one capacitor, eliminating the need for multiple supplies for driving RS232 levels.

Packaging

CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
Drawing
RoHS
LTC2870CFE#PBF TSSOP-28 FE C 05-08-1663 (EB) Yes
LTC2870CFE#TRPBF TSSOP-28 FE C 05-08-1663 (EB) Yes
LTC2870CUFD#PBF 4x5 QFN-28 UFD C 05-08-1712 Yes
LTC2870CUFD#TRPBF 4x5 QFN-28 UFD C 05-08-1712 Yes
LTC2870HUFD#PBF 4x5 QFN-28 UFD H 05-08-1712 Yes
LTC2870HUFD#TRPBF 4x5 QFN-28 UFD H 05-08-1712 Yes
LTC2870IFE#PBF TSSOP-28 FE I 05-08-1663 (EB) Yes
LTC2870IFE#TRPBF TSSOP-28 FE I 05-08-1663 (EB) Yes
LTC2870IUFD#PBF 4x5 QFN-28 UFD I 05-08-1712 Yes
LTC2870IUFD#TRPBF 4x5 QFN-28 UFD I 05-08-1712 Yes


LTC2870 Package Drawing
LTC2870 Package Drawing
LTC2870 Package Drawing
LTC2870 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LTC2870CFE#PBF TSSOP-28 C $7.43 $5.20 Yes
LTC2870CFE#TRPBF TSSOP-28 C $5.26 Yes
LTC2870CUFD#PBF 4x5 QFN-28 C $7.14 $5.00 Yes
LTC2870CUFD#TRPBF 4x5 QFN-28 C $5.06 Yes
LTC2870HUFD#PBF 4x5 QFN-28 H $9.45 $6.61 Yes
LTC2870HUFD#TRPBF 4x5 QFN-28 H $9.51 $6.67 Yes
LTC2870IFE#PBF TSSOP-28 I $8.54 $5.98 Yes
LTC2870IFE#TRPBF TSSOP-28 I $6.04 Yes
LTC2870IUFD#PBF 4x5 QFN-28 I $8.21 $5.75 Yes
LTC2870IUFD#TRPBF 4x5 QFN-28 I $5.81 Yes
Buy NowRequest Samples
* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Click here to view our complete list of demo boards

Designed for Automotive and Transportation Applications

Please contact your local sales representative for more information regarding reliability reports and AEC-Q100 data or to inquire about parts that are not included. For more information, view our Automotive and Transportation page

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LTC2870HUFD#PBF 4x5 QFN-28 H $9.45 $6.61 Yes
LTC2870HUFD#TRPBF 4x5 QFN-28 H $9.51 $6.67 Yes
LTC2870IUFD#PBF 4x5 QFN-28 I $8.21 $5.75 Yes
LTC2870IUFD#TRPBF 4x5 QFN-28 I $5.81 Yes
Buy NowRequest Samples
* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Applications

  • Software Selectable RS232/RS485/RS422 Interface
  • Point-of-Sale Terminals
  • Cable Repeaters
  • Protocol Translators

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Design Tools

Linear Technology provides a variety of custom design simulation tools and device models to allow even novice designers to quickly and easily evaluate circuits using high performance switching regulators, amplifiers, data converters, filters and more. Please visit our Design Tools page to view and download:

  • LTspice - A powerful SPICE simulator, schematic capture and waveform viewer with enhancements and models for easing the simulation of switching regulators
  • LTpowerCAD - A complete power supply selection, synthesis and design tool
  • LTpowerPlay - A development environment supporting Linear Technology's Digital Power System Management (PSM) products
  • PScope & QuikEval - USB-based product demonstration and data acquisition system for use with our ADCs, DACs, and more
  • Linduino - Arduino compatible system for developing and distributing firmware libraries and example code
  • LinearLab Tools - A collection of Matlab and Python programs that provide direct access to Linear Technology’s data converter evaluation boards
  • And More!

Technical Support