onsemi 74LCXH162244MEX

Overview

74LCXH162244 from Fairchild Semiconductor is a low-voltage 16-bit non-inverting buffer/line driver with bushold inputs and integrated 26 Ω output series resistors, designed for memory/address bus driving, clock distribution, and bidirectional bus transceiver applications at 2.3–3.6 V supply. It features nibble-level 3-STATE control (four independent OEn inputs), 5.3 ns max propagation delay at VCC = 3.0 V, and ±12 mA output drive capability.

For engineers reviewing the 74LCXH162244 datasheet, pinout, applications, or equivalent options, key selection considerations include its 48-pin SSOP package, bushold-enabled floating-input tolerance, on-die 26 Ω series termination, 5V-tolerant I/O, and nibble-selectable 3-STATE operation for flexible bus partitioning.

Technical Context

The 74LCXH162244 implements sixteen independent non-inverting buffers grouped into four 4-bit nibbles, each with dedicated active-low Output Enable (OEn) control. Its bushold circuitry actively maintains valid logic levels on unused I0–I15 inputs without external pull-ups, while integrated 26 Ω series resistors at all O0–O15 outputs suppress transmission-line overshoot/undershoot in high-speed PCB traces.

This device operates within 2.3–3.6 V VCC, supports 5V-tolerant control and data I/O, and delivers rail-to-rail CMOS-compatible output swing. Its advanced CMOS fabrication enables 5.3 ns tPD (max) at 3.0 V while maintaining <20 µA ICC quiescent current - optimized for low-noise, low-power, mixed-voltage system interfacing.

Key Specifications

Pinout & Package

Package: 48-Lead Small Shrink Outline Package (SSOP), JEDEC MO-118, 0.300" wide (Package Code MS48A).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16-bit buffer/line driver applications.

Compared with 74LCXH162244, the 74LVC162244ADGG lacks bushold and operates only down to 3.0 V, increasing design complexity for floating inputs; the SN74ALVCH162244GR provides bus-hold but omits integrated termination, requiring 16 additional resistors and raising total solution cost and board area.

Availability

74LCXH162244 is available at Aetrix Electronics and suitable for memory subsystems, clock distribution networks, industrial backplanes, and hot-swappable I/O modules requiring stable component supply, long-term lifecycle support, and guaranteed SSOP packaging consistency.

Supply support for 74LCXH162244 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 designer of high-performance analog and mixed-signal semiconductors, acquired by ON Semiconductor in 2016; known for innovation in low-voltage logic, power management, and interface solutions.

The 74LCXH162244 belongs to Fairchild's LCXH low-voltage CMOS logic family, engineered specifically for mixed-signal systems requiring 2.5 V/3.3 V operation with 5 V signal compatibility, reduced EMI, and enhanced bus reliability in space-constrained industrial and computing platforms.

FAQ

What is the function of bushold in the 74LCXH162244?

The bushold circuitry in the 74LCXH162244 actively maintains the last-valid logic state on any floating or unterminated data input (I0–I15), eliminating the need for external pull-up or pull-down resistors. This feature prevents undefined logic levels during power-up, hot-swap events, or partial bus usage - ensuring deterministic behavior without added BOM cost or PCB real estate. The 74LCXH162244 specifies bushold drive current from 45 µA to 75 µA depending on input voltage, enabling reliable hold across its 2.3–3.6 V operating range.

Does the 74LCXH162244 support true 5 V operation?

No, the 74LCXH162244 does not operate from a 5 V supply - its VCC range is strictly 2.3 V to 3.6 V. However, all inputs and outputs are 5 V tolerant, meaning they can safely interface with 5 V signal sources and loads without damage or level-shifting circuitry. This makes the 74LCXH162244 ideal for bridging 3.3 V logic domains to legacy 5 V peripherals. The 74LCXH162244 achieves this via internal clamping and robust oxide design, validated per its Absolute Maximum Ratings (VI up to 7.0 V).

How many independent 3-STATE controls does the 74LCXH162244 provide?

The 74LCXH162244 provides four independent active-low Output Enable (OEn) inputs - OEn1 through OEn4 - each controlling a 4-bit nibble (I0–I3/O0–O3, I4–I7/O4–O7, etc.). This nibble-level granularity allows selective disabling of bus segments without affecting the entire 16-bit path, supporting flexible memory banking, protocol-specific burst control, or partial power-down. When all OEn pins are tied together, the 74LCXH162244 functions as a standard 16-bit 3-STATE buffer.

What is the purpose of the 26 Ω series resistors in the 74LCXH162244 outputs?

The 26 Ω nominal series resistors integrated into each of the 16 outputs (O0–O15) of the 74LCXH162244 serve to dampen signal reflections on PCB traces, thereby reducing overshoot, undershoot, and EMI in high-speed digital interfaces. These resistors eliminate the need for 16 discrete external termination resistors, simplifying layout, lowering BOM cost, and improving impedance matching consistency. The 74LCXH162244's 26 Ω value is optimized for common 50 Ω trace environments and complements its 5.3 ns propagation delay for clean signal integrity up to ~100 MHz.

Is the 74LCXH162244 pin-compatible with other 16-bit buffers in the LCX family?

Yes, the 74LCXH162244 shares the same 48-pin SSOP (MS48A) footprint and pinout as other members of Fairchild's LCXH 16-bit buffer family, including the 74LCXH16244 and 74LCXH16373. All use identical nibble-based OEn mapping, I/O ordering, and power pin placement. However, functional differences exist - e.g., the 74LCXH16244 lacks bushold and output resistors, while the 74LCXH16373 is a latch, not a buffer. So while mechanical and electrical pin compatibility is maintained, the 74LCXH162244's unique bushold + termination features require functional validation in replacement scenarios.