LTC2871IUHF#PBF

Drivers, Receivers, Transceivers Overview

The LTC2871IUHF#PBF is a multiprotocol transceiver supporting RS-232, RS-422, and RS-485 standards. It integrates two independent RS-232 transceivers and one RS-485 transceiver on dedicated I/O lines within a 38-pin QFN package. The device operates on a single 3V to 5.5V supply with a logic interface range of 1.7V to 5.5V. It achieves data rates up to 20Mbps for RS-485 and 500kbps for RS-232. An internal DC/DC boost converter generates the required ±6.3V to +7V supplies for RS-232 operation using external passive components. Integrated termination resistors (120Ω for RS-485, 5kΩ for RS-232) are software-selectable.

Drivers, Receivers, Transceivers Feature Summary

• Pin-configurable multiprotocol support for RS-232, RS-422, and RS-485
• Integrated DC/DC boost converter eliminates need for multiple external power supplies
• Software-selectable automatic termination resistor switching
• Full failsafe operation for RS-485 receivers prevents UART lockup

Drivers, Receivers, Transceivers Applications

• Point-of-sale terminals
• Cable repeaters
• Protocol translators

Drivers, Receivers, Transceivers Procurement Notes

Verify the specific ordering suffix against manufacturer documentation to confirm lead-free status and packaging type. Confirm that the IUHF suffix corresponds to the industrial temperature grade (-40°C to 85°C) and the 38-lead QFN package format. Ensure compatibility with the intended PCB footprint and thermal requirements before procurement.

Drivers, Receivers, Transceivers Selection Notes

Select this component when independent control of two RS-232 channels and one RS-485 channel is required on dedicated lines. It is suitable for designs needing high ESD protection and integrated bus termination to reduce board space. Compare with the LTC2870 if shared I/O lines or different pin counts are acceptable for the application constraints.

Drivers, Receivers, Transceivers Part Context

This part belongs to the LTC2870/LTC2871 family of robust multiprotocol transceivers. While the LTC2870 shares similar core functionality, it utilizes shared I/O lines for its transceivers. The LTC2871 distinguishes itself by providing dedicated I/O lines for each transceiver, allowing simultaneous and independent protocol operation without pin conflicts.

Drivers, Receivers, Transceivers Replacement Considerations

LTC2871CUHF#PBF: Same package and function but commercial temperature grade (0°C to 70°C).

Drivers, Receivers, Transceivers FAQ

How does the LTC2871 handle RS-485 bus termination?

It features software-selectable integrated termination resistors. A logic high on the TE485 pin enables 120Ω resistors between pins A-B and Y-Z.

What is the maximum data rate for the RS-485 transceiver?

The maximum data rate for the RS-485 transceiver is 20Mbps.

Does the device require an external negative voltage supply for RS-232?

No, an integrated DC/DC boost converter generates the necessary negative supply (VEE) from the single positive VCC supply.