NXP Semiconductors 74ABT646AD,112

Overview

74ABT646AD,112 from NXP Semiconductors is an octal bus transceiver/register with 3-state outputs, combining bidirectional data transfer and independent A/B register storage in a single SO24 package. It supports real-time or clocked data routing between two 8-bit buses, delivers ±64 mA/−32 mA output drive, operates from 4.5 V to 5.5 V, and functions across −40 °C to +85 °C for industrial bus interface applications.

For engineers reviewing the 74ABT646AD,112 datasheet, 74ABT646AD,112 pinout, 74ABT646AD,112 application, or 74ABT646AD,112 equivalent, this device enables multiplexed bus management-simultaneous real-time transfer and register-based storage-with precise timing control via CPAB/CPBA clocks, DIR, OE, and SAB/SBA select inputs.

Technical Context

The 74ABT646AD,112 implements dual 8-bit D-type flip-flop registers (A-side and B-side) with independent clock inputs CPAB and CPBA, enabling asynchronous capture of data from either bus. Its transceiver logic supports four operational modes-real-time A→B, B→A, isolation storage, and stored-data transfer-controlled by OE (active LOW), DIR, and select pins SAB/SBA.

It uses BiCMOS technology to achieve high-speed propagation delays (tPLH/tPHL ≤ 5.6 ns at 5 V), low static current (ICC ≤ 250 µA), and robust ESD protection (HBM > 2000 V, MM > 200 V). Power-up 3-state and latch-up immunity (>500 mA per JESD78B Class II) ensure safe insertion and system-level reliability.

Key Specifications

Pinout & Package

74ABT646AD,112 is housed in a plastic small outline package (SO24, SOT137-1) with 24 leads and 7.5 mm body width, optimized for automated PCB assembly and thermal dissipation in dense board layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal bus transceiver/register applications.

Compared with 74ABT245DB,112 and 74ABT373AD,112, the 74ABT646AD,112 uniquely integrates both transceiver and dual-register functions in one SO24 device-reducing interconnect complexity, eliminating timing mismatches between discrete components, and enabling atomic bus state capture and replay operations.

Availability

74ABT646AD,112 is available at Aetrix Electronics and suitable for industrial backplane interfaces, modular PLC I/O expansion, and legacy bus protocol bridging requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for 74ABT646AD,112 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

NXP Semiconductors is a global semiconductor company specializing in secure connectivity solutions for automotive, industrial, and IoT applications, with leadership in high-performance logic and interface ICs.

The 74ABT646AD,112 belongs to NXP's ABT-series advanced BiCMOS logic family, designed specifically for high-speed, low-power bus interface and data staging in industrial control and communications infrastructure.

FAQ

What is the primary function of the 74ABT646AD,112?

The 74ABT646AD,112 is an octal bus transceiver/register with 3-state outputs that enables bidirectional data transfer between two 8-bit buses (A and B) while independently storing data in A-side and B-side registers. It supports real-time transfer, isolated register capture, and stored-data routing-all controlled by dedicated clock (CPAB/CPBA), direction (DIR), output enable (OE), and select (SAB/SBA) inputs. This functionality is fully implemented in the 74ABT646AD,112 device.

Does the 74ABT646AD,112 support hot-plug or live insertion?

Yes, the 74ABT646AD,112 supports live insertion and extraction, enabled by its BiCMOS process, power-up 3-state behavior, and robust ESD protection (HBM > 2000 V, MM > 200 V). These features prevent bus contention and latch-up during hot-swap events in modular backplane or rack-mounted systems. The 74ABT646AD,112 maintains safe high-impedance states throughout power transitions.

What are the valid supply voltage and operating temperature ranges for the 74ABT646AD,112?

The 74ABT646AD,112 operates from 4.5 V to 5.5 V supply voltage and functions across −40 °C to +85 °C ambient temperature. These specifications are guaranteed per NXP's recommended operating conditions and align with industrial-grade system requirements. All timing and drive performance metrics for the 74ABT646AD,112 are validated within this range.

How does the DIR pin affect data flow in the 74ABT646AD,112?

In the 74ABT646AD,112, the DIR (direction) pin determines bus assignment when OE is active (LOW): DIR = HIGH enables A→B real-time or stored transfer; DIR = LOW enables B→A real-time or stored transfer. DIR has no effect when OE = HIGH (isolation mode), where it only influences stored-data routing paths. This behavior is defined in the 74ABT646AD,112 function table and verified in Figure 5 of the datasheet.

What package type is used for the 74ABT646AD,112?

The 74ABT646AD,112 is packaged in a plastic small outline package (SO24) with 24 leads and 7.5 mm body width, designated SOT137-1. This surface-mount package meets JEDEC MS-013 standards and is compatible with standard reflow soldering processes. The pin configuration and mechanical dimensions for the 74ABT646AD,112 are documented in Figure 4 and Section 12 of the NXP datasheet.