onsemi 74ALVCH16244T

Overview

74ALVCH16244T from Fairchild Semiconductor is a low-voltage 16-bit non-inverting buffer/line driver with bushold inputs and 3-STATE outputs, designed for memory/address bus driving, clock distribution, and bidirectional bus interfacing in 1.65V–3.6V systems. It features nibble-level (4-bit) output enable control, 3 ns max propagation delay at 3.3V, 3.6V-tolerant I/O, and eliminates external pull-up resistors via active bushold circuitry.

For engineers reviewing the 74ALVCH16244T datasheet, pinout, applications, or equivalent options, key selection considerations include VCC operating range (1.65–3.6V), bushold input behavior, per-nibble 3-STATE control architecture, output drive strength (±24 mA), and TSSOP-48 package compatibility with high-density PCB layouts.

Technical Context

The 74ALVCH16244T implements sixteen independent non-inverting buffers, partitioned into four 4-bit groups (I0–I3/O0–O3; I4–I7/O4–O7; I8–I11/O8–O11; I12–I15/O12–O15), each with dedicated active-low OE inputs (OE1–OE4). Bushold circuitry actively maintains valid logic levels on floating data inputs without external biasing.

Its 3-STATE outputs support bidirectional bus contention management, with propagation delays tightly specified across three VCC ranges (1.65–1.95V, 2.3–2.7V, 2.7–3.6V), and output enable/disable times (tPZL/tPHZ ≤ 6.8 ns at 1.8V) optimized for synchronous low-voltage system timing.

Key Specifications

Pinout & Package

74ALVCH16244T is housed in a 48-lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153 compliant, 6.1 mm wide, with 0.5 mm lead pitch. Thermal and mechanical characteristics support reflow soldering per J-STD-020.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74ALVCH16244DGGR and 74LVC16244APAG, the 74ALVCH16244T uniquely combines bushold functionality, 3.6V I/O tolerance, and sub-3 ns propagation delay in a single industrial-qualified TSSOP-48 package - making it optimal for space-constrained, mixed-voltage bus interface designs where input biasing must be eliminated.

Availability

74ALVCH16244T is available at Aetrix Electronics and suitable for memory subsystems, low-voltage clock trees, industrial backplanes, and legacy bus interface designs requiring stable component supply and long-term industrial temperature support.

Supply support for 74ALVCH16244T 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 analog and power IC manufacturer, acquired by ON Semiconductor in 2016; its legacy logic portfolio remains widely deployed and supported.

The ALVCH family was engineered for low-voltage, high-speed bus buffering in portable and industrial systems where power efficiency, noise immunity, and input robustness were critical design constraints.

FAQ

What is the function of bushold in the 74ALVCH16244T?

The bushold circuitry in the 74ALVCH16244T actively maintains the last valid logic state on any floating data input (I0–I15), eliminating the need for external pull-up or pull-down resistors. This feature reduces BOM count, saves PCB space, and prevents undefined states that could cause downstream logic errors. The 74ALVCH16244T specifies bushold current of ±75 µA at 3.0V, ensuring reliable hold strength across its full 1.65–3.6V VCC range.

Can the 74ALVCH16244T operate with a 1.8V supply and interface to a 3.3V bus?

Yes, the 74ALVCH16244T supports VCC from 1.65V to 3.6V and features 3.6V-tolerant inputs and outputs. When powered at 1.8V, its outputs swing rail-to-rail (0V to 1.8V) but can safely receive and drive 3.3V logic levels without damage or level-shifting circuitry. This makes the 74ALVCH16244T ideal for voltage translation in mixed-supply systems such as FPGA-to-memory interfaces.

How does the nibble-control architecture of the 74ALVCH16244T benefit system design?

The 74ALVCH16244T provides four independent active-low output enable inputs (OE1–OE4), each controlling a 4-bit nibble (O0–O3, O4–O7, etc.). This allows partial bus gating - for example, disabling only the upper address nibble during DMA transfers while keeping lower bits active. The 74ALVCH16244T's nibble control reduces bus contention and simplifies timing-critical protocols without requiring multiple smaller buffers.

What is the maximum output drive capability of the 74ALVCH16244T?

The 74ALVCH16244T delivers ±24 mA output drive per pin at VCC = 3.0V, with VOL ≤ 0.55V and VOH ≥ 2.0V under those conditions. This enables direct driving of 50 Ω transmission lines, termination-matched buses, or multiple CMOS loads. The 74ALVCH16244T maintains usable drive strength even at minimum VCC (1.65V), supporting ≥±4 mA with VOL ≤ 0.45V - critical for low-power portable applications.

Is the 74ALVCH16244T compatible with standard TSSOP-48 PCB footprints?

Yes, the 74ALVCH16244T uses the JEDEC MO-153 compliant 48-lead Thin Shrink Small Outline Package (TSSOP), designated MTD48, with 6.1 mm body width and 0.5 mm lead pitch. Its mechanical dimensions and land pattern match industry-standard TSSOP-48 footprints used for SN74ALVCH16244 and similar devices, enabling drop-in layout reuse and simplified manufacturing transition.