Analog Devices Inc. LTC2873HUFD#PBF

LTC2873HUFD#PBF Product Summary

The LTC2873HUFD#PBF from Analog Devices Inc. is a versatile communication interface transceiver targeting industrial, instrumentation, and control system applications. Housed in a compact 24-lead 4mm x 5mm QFN package, this device integrates RS232 and RS485/422 physical layers into a single chip, providing engineers with a footprint-optimized and highly reliable solution for multi-protocol design requirements. Supporting half-duplex data transmission, the LTC2873HUFD#PBF operates across a wide supply voltage range (3.0V to 5.5V) and a broad ambient temperature window (-40°C to +125°C), making it suitable for harsh and demanding environments. The device is fully compliant with RoHS3, demonstrates high ESD robustness, and supports modern surface mount assembly.

Highlighted Characteristics of LTC2873HUFD#PBF

The standout attribute of the LTC2873HUFD#PBF is its configurable RS485 and RS232 interface, allowing for seamless protocol selection via pin control. Engineers are empowered to select the desired communication mode without additional level-shifting circuitry or relays. The device is suitable for data rates up to 20Mbps in RS485 mode and up to 1Mbps in RS232 fast mode, addressing both legacy and high-speed requirements.

Key functional highlights include:

Pin-selectable integrated termination resistors (120Ω for RS485, 5kΩ for RS232), which eliminate the need for external passive components and manual reconfiguration.

On-chip DC/DC boost converter to facilitate RS232 level generation from a single 3V–5.5V supply, further simplifying power sourcing in compact designs.

Advanced protection, with ±26kV Human Body Model (HBM) ESD rating on the bus pins.

Logic loopback self-test mode to facilitate diagnostics and reduce development time.

RS485 receiver capable of supporting up to 256 nodes, with failsafe operation on floating, shorted, or terminated inputs to prevent UART lockup.

7V to 5.5V flexible logic interface compatibility, supporting designs with low-voltage microcontrollers or FPGAs.

Operation Details and Use Cases of LTC2873HUFD#PBF

At the heart of the LTC2873HUFD#PBF’s appeal is the ability to dynamically transition between half-duplex RS485 and RS232 operational modes via logic pin configuration. This eliminates PCB rework when swapping protocols and enables rapid adaptation to diverse field bus requirements in industrial scenarios.

The unique integration of selectable on-chip termination distinctly benefits control networks—for instance, RS485 fieldbuses in factory automation or alarm systems—by enabling software or microcontroller-controlled impedance matching. Such integration not only minimizes bill-of-materials count but also enhances system reliability during installation and servicing.

The embedded DC/DC converter is instrumental for systems constrained to single low-voltage rails, such as remote sensors, traffic control submodules, or highway signage drivers. With this internal voltage generator, LTC2873HUFD#PBF produces compliant RS232 swings from as little as 3V input.

Loopback mode is especially valuable for production-line test scenarios and in situ diagnostics, letting the host verify physical layer transmission and reception paths before deploying the node.

Technical and Performance Data of LTC2873HUFD#PBF

Designers will find the LTC2873HUFD#PBF’s electrical characteristics precisely specified for robust industrial networks:

Operating supply voltage: 3.0V to 5.5V

Logic interface supply: 1.7V to Vcc

RS485 data rate: up to 20Mbps

RS232 data rate: selectable 250kbps or 1Mbps (fast mode), optimized via slew control

RS485 bus loading: supports up to 256 nodes

Current consumption: Down to 8μA in shutdown, typically 4–6mA in active transmission

Integrated ESD protection: ±26kV HBM on bus pins

Termination resistor enable/disable time: 100μs maximum

Propagation delay, skew, and rise/fall times tailored for minimal timing uncertainty over -40°C to 125°C operation

For RS485, receiver failsafe thresholds and input hysteresis safeguard against false triggering on noisy or floating lines. For RS232, the output meets TIA/EIA voltage and timing standards, confirming interoperability in legacy or new systems. The device’s fully specified output common-mode and differential voltages allow for robust communication across extended cable runs.

Package Details, Environmental Factors, and Regulatory Compliance for LTC2873HUFD#PBF

The LTC2873HUFD#PBF is packaged in a 24-pin 4x5mm QFN with an exposed pad for optimal thermal dissipation—crucial for designs operating at the +125°C junction limit. Surface-mount design simplifies automated assembly, while the package meets moisture sensitivity level (MSL) 1, allowing for standard reflow soldering without storage restrictions.

On compliance, the LTC2873HUFD#PBF is RoHS3 compliant and conforms to REACH standards, ensuring eligibility for modern sustainable manufacturing pipelines. The part is classified under ECCN EAR99 and harmonized tariff code 8542.39.0001 for simplified procurement and export.

Possible Alternative or Substitute Parts for LTC2873HUFD#PBF

When specifying components, engineers may need functionally equivalent solutions for supply chain resilience or second sourcing. For the LTC2873HUFD#PBF, key selection points include dual RS232/RS485 protocol transceivers, integrated termination, robust ESD protection, wide temperature operation, and single-rail operation with on-chip voltage generation.

Potential comparable devices include:

Texas Instruments MAX3160/MAX3161 series: These offer RS232/RS485 switching but may lack integrated termination and may have lower ESD ratings.

Intersil/RENESAS ISL83485IBZ: A robust RS485/RS232 transceiver, but with differences in supply voltage or packaging, requiring careful review for exact feature matching.

Analog Devices’ LT1785/LT1787 series: These offer RS485/RS232 solutions, though they may not include all integration and logic-level flexibility of LTC2873HUFD#PBF.

It is crucial that engineers compare data rate capabilities, protection, and pin compatibility before substituting the LTC2873HUFD#PBF; not all alternatives provide the same integrated termination and low-voltage logic interface versatility.

Conclusion

The LTC2873HUFD#PBF is a feature-rich multiprotocol transceiver for RS232 and RS485/422, targeted at modern industrial, instrumentation, and automation applications where ruggedness, integration, and flexibility are essential. It stands out with mode-selectability, robust fieldbus characteristics, and on-chip support for voltage generation and termination—all in a compact form factor. For designers and procurement professionals, the LTC2873HUFD#PBF addresses the critical needs of space-saving, reliability, and multi-protocol adaptation, streamlining both design and assembly. When high ESD resilience, broad supply and temperature support, and diagnostic flexibility are essential, this device represents a well-qualified choice for next-generation system communications.