LTC2854IDD#PBF

Drivers, Receivers, Transceivers Overview

The LTC2854IDD#PBF is a low-power, half-duplex RS-485/RS-422 transceiver operating on a 3.3V supply with a maximum data rate of 20Mbps. It features an integrated logic-selectable 120Ω termination resistor and supports up to 256 nodes per bus due to its one-eighth unit load receiver input resistance. The device includes failsafe circuitry guaranteeing a high output state during floating or shorted inputs. Enhanced ESD protection withstands ±25kV (HBM) without latchup. It operates within a temperature range of –40°C to +85°C and is housed in a 10-lead 3mm × 3mm DFN package.

Drivers, Receivers, Transceivers Feature Summary

• Integrated switchable 120Ω termination resistor controlled by the TE pin for optimized signal fidelity.
• High input impedance receiver representing a one-eighth unit load, supporting up to 256 nodes on the bus.
• Guaranteed failsafe operation ensuring a logic-high receiver output when inputs are open, shorted, or undriven.
• Robust protection against excessive power dissipation through current-limited drivers and thermal shutdown.

Drivers, Receivers, Transceivers Applications

• Level translator applications requiring RS-485/RS-422 compatibility.
• Backplane communication systems utilizing differential signaling.
• Industrial networks requiring high node density and bus termination control.

Drivers, Receivers, Transceivers Procurement Notes

Verify the component authenticity by checking the top marking LCQG against the datasheet specifications. Confirm the package type corresponds to the 10-lead DFN variant. Ensure the temperature grade matches the I-Grade requirement for industrial environments ranging from –40°C to +85°C before integration into the design.

Drivers, Receivers, Transceivers Selection Notes

Select this part for designs requiring integrated termination to simplify PCB layout and reduce component count. The half-duplex configuration suits single-ended bus architectures. Consider the H-grade variant if operation above 85°C is necessary. Verify that the 3.3V supply voltage aligns with the system power rails and that the 20Mbps rate meets bandwidth requirements.

Drivers, Receivers, Transceivers Part Context

This component belongs to the LTC2854/LTC2855 family of 3.3V RS-485/RS-422 transceivers. The LTC2854 is the half-duplex version, while the LTC2855 offers full-duplex operation. Both share similar features like integrated termination and failsafe protection but differ in driver output configurations and package options such as DFN-12 and SSOP-16.

Drivers, Receivers, Transceivers Replacement Considerations

Public confirmed substitutes include the LTC2850, LTC2851, LTC2852, and LTC2859. These parts offer similar RS-485/RS-422 functionality but may lack the integrated switchable termination feature found in the LTC2854. Verify pinout compatibility and electrical specifications before substitution.

Drivers, Receivers, Transceivers FAQ

How does the integrated termination resistor function?

The internal 120Ω termination resistor is enabled by driving the TE pin high. When disabled (TE low), the resistor is disconnected, allowing for external termination or multi-drop configurations without loading the bus.

What is the failsafe behavior of the receiver?

The receiver guarantees a logic-high output state at the RO pin when the A and B inputs are floating, shorted together, or terminated without a driven signal. This ensures a known idle state across the entire common mode range.

What is the maximum ESD rating for the interface pins?

The LTC2854 provides enhanced ESD protection capable of withstanding ±25kV using the Human Body Model (HBM) on the transceiver interface pins (A, B) without sustaining damage or latchup.