onsemi 74LVTH16652MEAX

Overview

74LVTH16652MEAX from Fairchild Semiconductor is a low-voltage 16-bit transceiver/register with 3-STATE outputs, designed for bidirectional data flow between A and B buses in mixed-voltage systems. It integrates D-type flip-flops per bit, supports real-time or registered transfer modes, delivers ±32 mA/±64 mA drive strength, operates from 2.7V to 3.6V VCC, and features bushold inputs eliminating external pull-ups - used in high-density memory expansion and backplane interface designs.

For engineers reviewing the 74LVTH16652MEAX datasheet, pinout, applications, or equivalent options, key selection criteria include dual-clock control (CPABn/CPBAn), independent byte-level select (SABn/SBAn) and output enable (OEABn/OEBAn), bus-hold functionality, and 56-pin SSOP package compatibility with JEDEC MO-118.

Technical Context

The 74LVTH16652MEAX implements two independent 8-bit transceiver/register sections, each with dedicated clock (CPABn/CPBAn), select (SABn/SBAn), and output enable (OEABn/OEBAn) controls. Its BiCMOS fabrication enables TTL-compatible 5V input tolerance while operating at 3.3V VCC, supporting live insertion/extraction and glitch-free power-up/down high-impedance states.

It provides four fundamental bus management functions: real-time A↔B transfer, stored-A-to-B + stored-B-to-A simultaneous transfer, isolated register storage per bus, and selective clocked capture without relying on output enables. All data inputs retain state via bushold, and outputs drive −32 mA (HIGH) / +64 mA (LOW) into terminated loads.

Key Specifications

Pinout & Package

74LVTH16652MEAX is packaged in a 56-lead Shrink Small Outline Package (SSOP), JEDEC MO-118 compliant, 0.300-inch body width, with 0.025-inch lead pitch. Pin numbering follows standard SSOP convention, pin 1 marked by dot or notch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16-bit registered transceiver applications.

Compared with SN74LVT16652DGGR and 74ALVCH16652T, the 74LVTH16652MEAX uniquely combines bushold, 5V-tolerant inputs, and SSOP packaging in a single industrial-qualified device - making it optimal for cost-sensitive, space-constrained upgrades of legacy 3.3V/5V hybrid systems.

Availability

74LVTH16652MEAX is available at Aetrix Electronics and suitable for memory expansion interfaces, backplane data bridges, hot-swappable I/O modules, and legacy ISA bus adapters requiring stable component supply across extended product lifecycles.

Supply support for 74LVTH16652MEAX 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

Fairchild Semiconductor was a U.S.-based semiconductor company specializing in analog and mixed-signal ICs, acquired by ON Semiconductor in 2016; its legacy logic portfolio remains widely deployed in industrial and telecom infrastructure.

The 74LVTH16652MEAX belongs to Fairchild's LVTH (Low-Voltage TTL-High-Speed) logic family, engineered for 3.3V systems needing TTL-compatible interfacing, high drive strength, and robust bus management - targeting backplane, memory, and modular I/O applications.

FAQ

What is the package type and lead count of the 74LVTH16652MEAX?

The 74LVTH16652MEAX uses a 56-lead Shrink Small Outline Package (SSOP) per JEDEC MO-118, with 0.300-inch body width and 0.025-inch lead pitch. This SSOP variant (package number MS56A) is distinct from the TSSOP version (MTD56) used in the 74LVTH16652MTD. The 'X' suffix denotes tape-and-reel packaging, not a package change.

Does the 74LVTH16652MEAX support 5V logic inputs while operating at 3.3V VCC?

Yes, the 74LVTH16652MEAX supports input voltages from 0V to 5.5V regardless of VCC (2.7V–3.6V), enabling direct interfacing with 5V TTL or CMOS peripherals without external level shifters. This is explicitly guaranteed in the Recommended Operating Conditions table and confirmed by VI absolute maximum rating of +7.0V.

How does the bushold feature work on the 74LVTH16652MEAX, and what design benefit does it provide?

The 74LVTH16652MEAX incorporates bushold circuitry on all data inputs (A0–A15, B0–B15), which actively maintains the last valid logic state when inputs float. It sources/sinks ±75 µA to hold VI near 0.8V or 2.0V, eliminating the need for 32 external pull-up resistors. This reduces BOM cost, PCB area, and potential signal integrity issues from weak pull-ups.

What are the timing requirements for clock inputs CPABn and CPBAn on the 74LVTH16652MEAX?

The 74LVTH16652MEAX requires a minimum pulse width of 3.3 ns for CPABn and CPBAn HIGH or LOW states, with setup time of 1.2–2.8 ns and hold time of 0.0–0.5 ns relative to data edges. Propagation delay from clock to output is 1.0–5.6 ns, and maximum clock frequency is rated at 150 MHz under CL = 50 pF loading conditions.

Can the 74LVTH16652MEAX be used in hot-swap applications, and what features enable this?

Yes, the 74LVTH16652MEAX supports live insertion/extraction per its datasheet features. Key enablers include power-up/power-down high-impedance outputs (preventing bus contention during power ramp), bushold inputs (maintaining valid states on floating lines), and latch-up immunity exceeding 500 mA - all validated for use in modular backplane and I/O carrier systems.