LTC2870CUFD#TRPBF

Drivers, Receivers, Transceivers Overview

The LTC2870CUFD#TRPBF is a multiprotocol transceiver supporting RS232, RS485, and RS422 protocols. It operates on a single 3V to 5.5V supply voltage with a logic interface range of 1.7V to 5.5V. The device integrates two RS232 transceivers and one RS485 transceiver on shared I/O lines. It supports data rates up to 20Mbps for RS485 and 500kbps for RS232. An integrated DC/DC boost converter generates the required positive and negative supplies for RS232 operation using a single external inductor and capacitor. The component is housed in a 28-lead 4mm × 5mm QFN package.

Drivers, Receivers, Transceivers Feature Summary

• Pin-controlled integrated termination resistors allow easy interface reconfiguration without external components.
• Half-duplex switching capability enables four-wire and two-wire RS485 configurations.
• Logic loopback mode steers driver inputs to receiver outputs for diagnostic self-testing.
• RS485 receivers support up to 256 nodes per bus with full failsafe operation.

Drivers, Receivers, Transceivers Applications

• Point-of-Sale Terminals
• Cable Repeaters
• Protocol Translators

Drivers, Receivers, Transceivers Procurement Notes

Verify the specific ordering suffix #TRPBF indicates tape and reel packaging when sourcing this component. Confirm that the C-grade designation corresponds to the commercial operating temperature range of 0°C to 70°C. Ensure the QFN package dimensions match the 4mm × 5mm footprint requirements of the target PCB layout before finalizing procurement orders.

Drivers, Receivers, Transceivers Selection Notes

Select the LTC2870 over the LTC2871 when shared I/O lines for RS232 and RS485 are acceptable, as it offers a more compact 28-pin form factor. Verify that the system requires only two RS232 channels and one RS485 channel. Consider the H-grade variant if an extended operating temperature range up to 125°C is necessary for the application environment.

Drivers, Receivers, Transceivers Part Context

This component belongs to the LTC2870/LTC2871 family of robust pin-configurable multiprotocol transceivers manufactured by Analog Devices Inc. The series is designed to simplify serial communication interfaces by integrating multiple protocol drivers and receivers into a single chip, reducing board space and component count compared to discrete solutions.

Drivers, Receivers, Transceivers Replacement Considerations

The LTC2871 serves as a functional alternative within the same family but utilizes a 38-pin package with dedicated I/O lines instead of shared ones. Direct substitution requires verifying pin compatibility and ensuring the additional pins can be managed or left unconnected in the existing design.

Drivers, Receivers, Transceivers FAQ

How does the device handle RS485 termination?

The LTC2870 features pin-controlled integrated termination resistors. A logic high on the TE485 pin enables a 120Ω resistor between pins A and B, eliminating the need for external termination components.

What is the purpose of the Logic Loopback Mode?

The Logic Loopback Mode internally routes the driver input logic levels to the receiver output pins. This feature allows for diagnostic self-testing of the transceiver circuitry without requiring external loopback connectors.

Can the device operate with a 1.7V logic supply?

Yes, the device supports a logic interface voltage (VL) ranging from 1.7V to 5.5V, allowing compatibility with low-voltage logic systems while maintaining a separate 3V to 5.5V supply for the transceiver drivers.