LTC2855IDE#PBF

Drivers, Receivers, Transceivers Overview

The LTC2855IDE#PBF is a full-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 input impedance. The device includes failsafe receiver operation, current-limited drivers, and thermal shutdown protection. It withstands ±15kV HBM ESD on interface pins and operates within a temperature range of –40°C to +85°C in a 12-lead DFN package.

Drivers, Receivers, Transceivers Feature Summary

• Integrated switchable 120Ω termination resistor for optimized signal fidelity
• Full-duplex architecture with independent driver and receiver channels
• Guaranteed failsafe receiver output under floating or shorted input conditions
• High input impedance supporting extensive node counts on the bus

Drivers, Receivers, Transceivers Applications

• Industrial control and instrumentation networks
• Supervisory Control and Data Acquisition (SCADA) systems
• Building automation and security systems

Drivers, Receivers, Transceivers Procurement Notes

Verify the specific ordering suffix against manufacturer documentation to confirm lead-free status and package variant. Confirm that the I-grade temperature rating aligns with system requirements before procurement. Ensure proper handling procedures are followed for the surface-mount DFN package during assembly.

Drivers, Receivers, Transceivers Selection Notes

Select this component when full-duplex communication is required alongside integrated line termination capabilities. The one-eighth unit load specification allows for higher node density compared to standard receivers. Verify that the 3.3V supply voltage matches the system logic levels and that the 20Mbps data rate meets application bandwidth needs.

Drivers, Receivers, Transceivers Part Context

This part belongs to the LTC2854/LTC2855 family of low-power RS-485/RS-422 transceivers. While the LTC2854 provides half-duplex functionality, the LTC2855 offers full-duplex operation. Both share similar protection features and termination options but differ in channel configuration and pinout assignments.

Drivers, Receivers, Transceivers Replacement Considerations

The datasheet indicates pin compatibility with the LTC2862 and LT1785. Verify functional equivalence regarding duplex mode and termination integration before substitution.

Drivers, Receivers, Transceivers FAQ

How does the integrated termination resistor function?

The internal 120Ω termination resistor can be enabled via the TE pin. When active, it connects between pins A and B to reduce signal reflections without requiring external components.

What is the failsafe behavior of the receiver?

The receiver guarantees a high output state if the inputs are floating, shorted together, or terminated without a driving signal, ensuring a known idle state.

What is the maximum ESD protection rating for the interface pins?

The LTC2855 withstands ±15kV Human Body Model (HBM) ESD on the Y, Z, A, and B interface pins without latchup or damage.