Nexperia USA Inc. 74HCT244DB,112

Overview

74HCT244DB,112 from Nexperia is an octal non-inverting 3-state buffer/line driver with TTL-compatible inputs and two independent output-enable controls (1OE, 2OE), operating at 4.5 V to 5.5 V supply. It delivers 6 mA output drive capability, 11 ns typical propagation delay at 4.5 V, and supports industrial temperature range (−40 °C to +125 °C) in a 20-lead SSOP package. It is used for bidirectional bus interfacing in microcontroller peripheral expansion and memory address/data buffering.

For engineers reviewing the 74HCT244DB,112 datasheet, 74HCT244DB,112 pinout, 74HCT244DB,112 application, or 74HCT244DB,112 equivalent, key selection criteria include TTL-level input compatibility, dual 4-bit enable control, 3-state bus contention management, and SSOP20 footprint suitability for high-density PCB layouts.

Technical Context

The device implements two independent 4-bit buffer sections, each controlled by its own active-low output-enable input (1OE for Y0–Y3, 2OE for Y4–Y7). Inputs accept standard TTL voltage thresholds (VIH = 2.0 V min, VIL = 0.8 V max at VCC = 5 V), ensuring direct compatibility with legacy 5 V logic families without level translation.

Each output drives up to ±6 mA while maintaining VOH ≥ 3.7 V and VOL ≤ 0.4 V under load, and transitions exhibit 5 ns typical rise/fall time (tr/tf) into 15 pF. The 3-state disable timing (ten/tdis ≈ 15–45 ns) ensures clean bus release before new drivers activate.

Key Specifications

Pinout & Package

74HCT244DB,112 uses the SOT339-1 (SSOP20) package: 20-pin shrink small outline plastic package, 0.65 mm pitch, body width 5.3 mm, height 1.8 mm. Pin 1 is index-marked; pin 10 is GND; pin 20 is VCC.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal 3-state buffer applications.

Compared with 74HCT244D,118 and SN74HCT244N, the 74HCT244DB,112 offers superior PCB area efficiency (5.3 mm × 7.2 mm), tighter timing (11 ns vs. 15 ns), and modern RoHS-compliant packaging-making it optimal for volume-manufactured industrial controllers requiring high pin density and thermal reliability.

Availability

74HCT244DB,112 is available at Aetrix Electronics and suitable for industrial I/O modules, retro-computing hardware restoration, and microcontroller peripheral expansion requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 74HCT244DB,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

Nexperia is a global semiconductor expert delivering high-performance logic, analog, and MOSFET solutions optimized for efficiency, reliability, and manufacturability in industrial, automotive, and consumer applications.

The 74HCT244 series belongs to Nexperia's industry-standard logic portfolio, designed specifically to replace legacy TTL devices with improved noise immunity, lower power, and enhanced ESD robustness-targeting bus interface and signal conditioning in harsh environments.

FAQ

What is the maximum clock frequency supported by 74HCT244DB,112?

The 74HCT244DB,112 is not a clocked device-it has no internal clock or synchronous operation. Its usable data rate depends on propagation delay (11 ns typ) and bus capacitance. For a 15 pF load, it reliably supports asynchronous bus toggling up to ~20 MHz with timing margin, assuming proper PCB layout and termination.

Can 74HCT244DB,112 drive a 50 Ω transmission line directly?

No. With only ±6 mA output drive and no controlled-impedance output stage, it cannot properly terminate or drive 50 Ω lines. Use it to feed a dedicated line driver (e.g., SN65LVDS1) or add series termination (e.g., 33 Ω) for short (<10 cm), low-speed connections where signal integrity is non-critical.

Is 74HCT244DB,112 pin-compatible with 74HC244DB,112?

Yes-identical pinout and package (SOT339-1). However, 74HC244DB,112 uses CMOS input thresholds (VIH = 3.15 V min at 4.5 V), so it will not reliably recognize 74LS outputs (2.7 V HIGH). Use 74HCT244DB,112 when interfacing with TTL-family sources.

Does 74HCT244DB,112 require external pull-up resistors on its outputs?

No. Its 3-state outputs have no internal pull-ups; they present true high-impedance (Z) when disabled. Pull-ups are only needed if the driven bus requires a defined state during disable-e.g., I²C-like open-drain emulation-but this is not standard usage and adds unnecessary power draw.