Texas Instruments SN74LVC863APWR

Overview

SN74LVC863APWR 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-tolerant inputs, delivers 6.1 ns max propagation delay at 3.3 V, and supports partial-power-down via Ioff. It is used in industrial backplane interfaces requiring level translation between 3.3-V logic and legacy 5-V peripherals.

For engineers reviewing the SN74LVC863APWR datasheet, SN74LVC863APWR pinout, SN74LVC863APWR application, or SN74LVC863APWR equivalent, key selection criteria include bidirectional 9-bit channel count, dual OEAB/OEBA control per direction, 3.3-V/5-V mixed-mode compatibility, and TSSOP-24 package suitability for high-density PCB layouts.

Technical Context

This device implements independent directional control using two OEAB (A-to-B enable) and two OEBA (B-to-A enable) inputs per 9-bit port, enabling flexible timing-either simultaneous or staggered bus activation. Its Ioff circuitry actively disables outputs during power-down, preventing backflow current when VCC = 0 V.

The transceiver supports true 5-V-tolerant inputs while powered at 1.65–3.6 V, allowing direct connection to 5-V drivers without external level shifters. Output drive strength is specified at ±24 mA at 3 V, with guaranteed VOL ≤ 0.55 V and VOH ≥ 2.2 V under full load, ensuring noise margin compliance in noisy industrial environments.

Key Specifications

Pinout & Package

TSSOP-24 package (PW), 7.8 mm × 4.4 mm body, 0.65 mm pitch, 1.2 mm max height, RoHS-compliant NiPdAu lead finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC863APWR, SN74LVC863ADWR offers mechanical robustness and easier hand-soldering at the cost of board space, while SN74LVC863ADGVR achieves maximum miniaturization but demands tighter process control - all three share identical timing, voltage, and logic behavior.

Availability

SN74LVC863APWR is available at Aetrix Electronics and suitable for industrial backplane interfaces, automated test equipment fixtures, programmable logic controller I/O modules, embedded data acquisition systems, and mixed-voltage sensor hubs requiring stable component supply across long production lifecycles.

Supply support for SN74LVC863APWR 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 specializing in analog, embedded processing, and connectivity technologies, with decades of experience in industrial-grade logic and interface solutions.

The SN74LVC863A belongs to TI's LVC (Low-Voltage CMOS) logic family, engineered for high-speed, low-power, mixed-voltage interoperability in industrial automation, test equipment, and communications infrastructure.

FAQ

What is the recommended power-up sequence for SN74LVC863APWR to avoid bus contention?

TI recommends tying OEAB1, OEAB2, OEBA1, and OEBA2 to VCC through pullup resistors (minimum value determined by driver sink capability) during power-up. This ensures all outputs remain in high-impedance state until system firmware initializes direction control. The SN74LVC863APWR inherently enters high-Z on power-up and power-down, but external pullups guarantee deterministic behavior in all supply ramp conditions.

Does SN74LVC863APWR support true 5-V output drive when VCC = 3.3 V?

No. The SN74LVC863APWR outputs are CMOS-compatible with VOH ≥ 2.2 V and VOL ≤ 0.55 V at VCC = 3.3 V and IO = ±24 mA - sufficient to drive 5-V TTL inputs but not to source/sink 5-V rail currents. Its 5-V tolerance applies only to inputs; outputs swing between GND and VCC, making it a level translator, not a 5-V driver.

Can SN74LVC863APWR replace SN74LVC863ADW in an existing SOIC-24 design?

No direct replacement is possible without PCB redesign. SN74LVC863APWR uses TSSOP-24 (7.8 mm × 4.4 mm, 0.65 mm pitch), while SN74LVC863ADW uses SOIC-24 (15.4 mm × 7.5 mm, 1.27 mm pitch). Footprint, solder stencil, and reflow profile differ significantly. Migration requires layout revision and qualification per IPC-A-610 Class 2/3 standards.

How does the Ioff feature of SN74LVC863APWR protect against backflow current?

When VCC = 0 V, the SN74LVC863APWR's Ioff circuitry disables internal output FETs, limiting leakage to ±10 µA even if 5.5 V is applied to A or B pins. This prevents reverse current from a live bus into a powered-down section - a critical safeguard in modular systems where subsystems may be powered independently or hot-swapped.

What is the maximum data rate supported by SN74LVC863APWR in a 9-bit parallel bus configuration?

Based on its 6.1 ns max tpd at 3.3 V, the SN74LVC863APWR supports reliable 9-bit parallel data transfer up to ~80 MHz (1/(2 × tpd)). Real-world sustained rates depend on trace length, termination, and noise margin; for clean 50-Ω controlled-impedance traces, 50–66 MHz burst-mode operation is routinely achieved in industrial backplane designs using SN74LVC863APWR.