Texas Instruments SN74LVC863ADWR

Overview

SN74LVC863ADWR from Texas Instruments is a 9-bit bus transceiver with 3-state outputs, designed for asynchronous bidirectional data transfer between A and B buses in mixed-voltage systems. It operates from 1.65 V to 3.6 V, accepts 5.5-V inputs, delivers 6.1-ns max propagation delay at 3.3 V, and supports partial-power-down via Ioff. It enables level translation in 3.3-V/5-V interfacing applications such as memory expansion and FPGA-to-ASIC interconnects.

For engineers reviewing the SN74LVC863ADWR datasheet, SN74LVC863ADWR pinout, SN74LVC863ADWR application, or SN74LVC863ADWR equivalent, key selection criteria include bidirectional 3-state control logic (OEAB/OEBA), 9-channel channel count, 24-pin TSSOP package, Ioff-enabled power-down isolation, and 5.5-V-tolerant inputs for mixed-mode signal operation.

Technical Context

This device implements dual-directional bus transceivers with independent output-enable controls per direction: OEAB1/OEAB2 enable A→B transmission, while OEBA1/OEBA2 enable B→A transmission. Its logic diagram confirms noninverting signal path and latch capability when all OE inputs are low.

The SN74LVC863ADWR uses LVC-series CMOS technology with rail-to-rail input voltage tolerance (0–5.5 V) and VCC-referenced output drive. It features guaranteed high-impedance state during power-up/down and meets JESD 17 latch-up (>250 mA) and JESD 22 ESD (2000-V HBM, 200-V MM, 1000-V CDM) specifications.

Key Specifications

Pinout & Package

TSSOP-24 (PW) package: 7.9 mm × 4.5 mm × 1.2 mm body, 0.65-mm lead pitch, gull-wing leads, RoHS-compliant NiPdAu finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 9-bit bus transceiver applications.

Compared with SN74LVC863ADWR, SN74LVC863APWR offers identical performance in a functionally interchangeable TSSOP package, while SN74LVC863ADGVR provides a 40% smaller footprint at the cost of tighter assembly constraints and marginally higher thermal resistance.

Availability

SN74LVC863ADWR is available at Aetrix Electronics and suitable for industrial automation interfaces, automotive sensor hubs, and FPGA-based prototyping platforms requiring stable component supply and long-term lifecycle support.

Supply support for SN74LVC863ADWR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader delivering analog, embedded processing, and connectivity solutions with emphasis on reliability, efficiency, and design enablement.

The SN74LVC863ADWR belongs to TI's LVC logic family-designed for low-voltage, high-speed, mixed-signal interfacing in industrial, automotive, and communications equipment where voltage translation and bus isolation are critical.

FAQ

What is the recommended power-up sequence for SN74LVC863ADWR?

TI recommends tying OEAB1, OEAB2, OEBA1, and OEBA2 to VCC through pullup resistors during power-up to ensure outputs remain in high-impedance state until valid control signals are established. The SN74LVC863ADWR inherently maintains 3-state during power transitions, but external pullups prevent bus contention in systems with asynchronous power rails. This practice applies regardless of VCC ramp rate or sequencing order.

Does SN74LVC863ADWR support true bidirectional data flow on the same pins?

Yes, the SN74LVC863ADWR supports true bidirectional operation: A1–A9 and B1–B9 are I/O pins capable of driving or receiving data depending on OEABx/OEBAx states. When OEAB1 and OEAB2 are low, A-side drivers are enabled and B-side receivers are active; when OEBA1 and OEBA2 are low, B-side drivers drive A-side receivers. No external direction-control logic is required.

Can SN74LVC863ADWR be used in a 5-V-only system?

No-SN74LVC863ADWR requires VCC between 1.65 V and 3.6 V and is not rated for 5-V supply. However, its inputs tolerate up to 5.5 V, so it can safely interface with 5-V signal sources while powered from 3.3 V or lower. Using it with 5-V VCC would exceed absolute maximum ratings and risk permanent damage.

What is the meaning of "Latch A and B" in the SN74LVC863ADWR function table?

When all four OE inputs (OEAB1, OEAB2, OEBA1, OEBA2) are low, the SN74LVC863ADWR enters latch mode: the last valid data present on A and B buses is held at the outputs, effectively freezing bus state. This feature supports hold-mode operations in test equipment or fault-isolation scenarios without requiring continuous clocking or external latches.

How does Ioff protection work in SN74LVC863ADWR during partial power-down?

The SN74LVC863ADWR's Ioff circuitry disables all output drivers and isolates input/output paths when VCC = 0 V, limiting current flow to ±10 µA even if 5.5-V signals are applied to A/B pins. This prevents damaging backfeed current into a powered-down section of the system-critical for hot-swap capable backplanes or modular subsystems where power domains are independently controlled.