Nexperia USA Inc. 74HCT244D,652

Overview

74HCT244D,652 from Nexperia is an octal non-inverting 3-state buffer/line driver with TTL-compatible inputs and dual independent output-enable controls (1OE, 2OE), operating at 4.5 V to 5.5 V supply. It provides eight buffered outputs split into two groups of four, each controlled by a separate enable pin, and delivers 6 mA sink/source drive capability at 5 V with propagation delay as low as 11 ns (typical). It is used in bidirectional bus interfacing between microcontrollers and peripheral ICs in industrial control backplanes.

For engineers reviewing the 74HCT244D,652 datasheet, 74HCT244D,652 pinout, 74HCT244D,652 application, or 74HCT244D,652 equivalent, key selection criteria include TTL-level input compatibility, dual 3-state enable architecture, SO20 package thermal performance, and guaranteed operation across -40 °C to +125 °C ambient.

Technical Context

This device implements two independent 4-bit non-inverting buffers, each with active-low 3-state output control. Its TTL-compatible input thresholds (VIH = 2.0 V min, VIL = 0.8 V max at VCC = 5 V) ensure direct interfacing with legacy 5 V logic families without level translation. The dual OE structure enables selective isolation of two data lanes on a shared bus.

Each output supports ±6 mA DC drive at VCC = 4.5 V, with VOL ≤ 0.26 V and VOH ≥ 3.7 V under load. Propagation delay (tpd) is 11 ns typical (CL = 15 pF, VCC = 4.5 V), and enable/disable times (ten/tdis) are 15 ns/15 ns typical - critical for high-speed bus arbitration in real-time embedded systems.

Key Specifications

Pinout & Package

74HCT244D,652 is housed in a plastic small outline package (SO20, SOT163-1) with 20 leads, 7.5 mm body width, and gull-wing leads. Thermal resistance (Rth(j-a)) is 109 K/W, supporting continuous operation at full load in ambient up to 85 °C with minimal heatsinking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HCT244N and 74LVC244APW, the 74HCT244D,652 uniquely balances 5 V TTL compatibility, SO20 manufacturability, and extended temperature support - making it the sole option qualified for automotive under-hood and industrial convection-cooled deployments.

Availability

74HCT244D,652 is available at Aetrix Electronics and suitable for industrial PLC backplanes, automotive body control modules, automated test equipment, and medical imaging subsystems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 74HCT244D,652 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 focused on essential semiconductors for power management, logic, analog, and MOSFETs - serving automotive, industrial, computing, and consumer markets with high-volume, high-reliability components.

The 74HCT244D,652 belongs to Nexperia's industry-standard 74HCT logic family, designed specifically for robust 5 V TTL-to-CMOS interfacing in harsh-environment applications demanding extended temperature operation and high ESD resilience.

FAQ

What is the maximum output current per pin for 74HCT244D,652?

The absolute maximum DC output current per pin is ±35 mA, but the recommended operating condition specifies ±6 mA at VCC = 4.5 V. Exceeding ±6 mA continuously degrades VOH/VOL performance and increases junction temperature beyond safe limits in the SO20 package. Derating curves in Table 4 confirm 500 mW total power dissipation limit with linear derating above 109 °C ambient.

Can 74HCT244D,652 interface directly with 3.3 V microcontrollers?

Yes - its TTL-compatible inputs accept VIH ≥ 2.0 V, which is satisfied by most 3.3 V CMOS outputs (typically VOH ≥ 2.4 V). No level shifter is needed. However, outputs swing rail-to-rail (0 V to VCC), so connecting to 3.3 V-only inputs requires series resistors or clamping diodes to prevent overvoltage damage unless the receiving device has 5 V tolerant inputs.

Is the SO20 package lead-free and RoHS compliant?

Yes - 74HCT244D,652 (SOT163-1) is manufactured using lead-free solderable terminations and complies with EU RoHS Directive 2011/65/EU and REACH Regulation (EC) No. 1907/2006. The device carries the "Pb-free" marking on the top-side laser marking and is rated for standard SnPb and lead-free reflow profiles per JEDEC J-STD-020.

How does the dual OE architecture improve bus reliability?

Dual OE (1OE/2OE) enables independent control of two 4-bit output groups, preventing bus contention when multiple devices share a common line. For example, while Group 1 drives data to a DAC, Group 2 can remain high-impedance during ADC sampling - eliminating shoot-through current and reducing ground bounce. This separation also simplifies timing analysis in multi-master systems.