Texas Instruments SN74ABT853DW

Overview

SN74ABT853DW from Texas Instruments is an 8-bit to 9-bit parity bus transceiver with integrated parity generator/checker, ERR flag latch, and high-drive outputs (−32 mA IOH, 64 mA IOL). It operates at 4.5–5.5 V over −40°C to 85°C and supports bidirectional A↔B data transfer with parity validation in industrial backplane and memory subsystem applications.

For engineers reviewing the SN74ABT853DW datasheet, SN74ABT853DW pinout, SN74ABT853DW application, or SN74ABT853DW equivalent, this device delivers deterministic parity-error detection, power-up/down high-impedance isolation, and EPIC-IIIB™ BiCMOS logic for low-noise, high-speed bus interfacing in legacy TTL-compatible systems.

Technical Context

The SN74ABT853DW implements a dual-bus transceiver architecture with independent OEA/OEB controls, enabling A→B data flow with odd-parity generation or B→A flow with parity checking via open-collector ERR output. Its internal 9-bit parity engine computes Σ(A1–A8) and compares Σ(B1–B8 + PARITY) to assert ERR on mismatch.

Control logic includes LE for sampling/storing ERR state and CLR for clearing the error latch; timing parameters specify minimum LE pulse width (3.5 ns), setup/hold for B/PARITY relative to LE↓ (9.4 ns / 0 ns), and propagation delays as low as 1.0 ns (tPHL from CLR to ERR).

Key Specifications

Pinout & Package

SN74ABT853DW uses a 24-pin SOIC (DW) package with 0.300-inch body width, JEDEC MS-013AC compliant, RoHS-compliant NiPdAu lead finish, and MSL Level-1 rating (260°C reflow).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit parity transceiver applications.

Compared with SN74ABT853DW, SN74ABT854DW removes parity generation capability but adds per-byte enable granularity, while SN74ACT853N trades speed and drive strength for lower quiescent current and improved noise rejection - both require layout review due to differing AC characteristics despite shared DW footprint.

Availability

SN74ABT853DW is available at Aetrix Electronics and suitable for industrial backplane interfacing, memory subsystem parity checking, and legacy system bus expansion requiring stable component supply across extended product lifecycles.

Supply support for SN74ABT853DW 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 logic solutions, with over 50 years of innovation in high-reliability interface ICs.

The SN74ABT853DW belongs to TI's ABT logic family, designed specifically for high-speed, low-noise 5-V TTL-compatible bus interfacing in industrial and computing systems requiring deterministic parity validation.

FAQ

What is the function of the PARITY pin on the SN74ABT853DW?

The PARITY pin on the SN74ABT853DW outputs an odd-parity bit computed from the A1–A8 inputs during A→B data transfer. During B→A transfer, this same pin serves as an input to the internal parity checker, comparing Σ(B1–B8 + PARITY) to detect mismatches that trigger the ERR flag. It is not a dedicated output-only or input-only signal but a bidirectional parity channel integral to the device's error-detection mechanism.

Does the SN74ABT853DW support hot insertion or live bus swapping?

The SN74ABT853DW supports controlled bus isolation during power transitions: its outputs enter high-impedance state when VCC drops below 2.1 V, preventing contention during partial power-down. However, it lacks explicit hot-swap circuitry (e.g., slew-rate limiting, back-to-back FETs), so live insertion into an energized bus requires external current-limiting and sequencing design to avoid latch-up or overstress per absolute maximum ratings (e.g., VI ≤ 7 V, IO ≤ 128 mA).

How does the inverted parity mode work on the SN74ABT853DW?

When both OEA and OEB are low, the SN74ABT853DW enters inverted parity mode: it generates even parity instead of odd parity on the PARITY pin. This creates a deliberate parity mismatch during subsequent B→A transfer, forcing ERR low regardless of data integrity - a hardware-level diagnostic feature allowing system designers to verify ERR path functionality without corrupting actual data.

What is the recommended pullup resistor value for the open-collector ERR output of the SN74ABT853DW?

For the open-collector ERR output of the SN74ABT853DW, a 4.7-kΩ pullup to 5 V is recommended to ensure valid logic-high levels (>2.0 V) while limiting sink current to <1 mA when ERR is asserted low. This value balances rise time (with typical Cio ≈ 10.5 pF) and power consumption, and aligns with TI's application guidance for ABT-series ERR pins driving standard TTL loads.

Can the SN74ABT853DW operate reliably at 4.5 V supply with full timing specifications?

Yes, the SN74ABT853DW is fully specified at 4.5 V: all recommended operating conditions, including tPLH/tPHL (max 6.4 ns), tSU (9.4 ns), and VOL/VOH limits, apply across 4.5–5.5 V. Electrical characteristics tables confirm VOH ≥ 2.0 V and VOL ≤ 0.55 V at VCC = 4.5 V with rated IOL/IOH, ensuring interoperability with 5-V TTL families under worst-case voltage and temperature conditions.