Nexperia USA Inc. 74HCT244D,653

Overview

74HCT244D,653 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. It is used in bidirectional bus interfacing between microcontrollers and peripheral I/O expansion circuits.

For engineers reviewing the 74HCT244D,653 datasheet, 74HCT244D,653 pinout, 74HCT244D,653 application, or 74HCT244D,653 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 industrial temperature range.

Technical Context

The 74HCT244D,653 implements two independent 4-bit non-inverting buffer sections sharing a common VCC and GND. Each section features active-low output enables (1OE for Y0–Y3, 2OE for Y0'–Y3') that place their respective outputs in high-impedance state when asserted HIGH. Input clamp diodes allow safe interfacing to voltages exceeding VCC when used with current-limiting resistors.

Its TTL-compatible input thresholds (VIH = 2.0 V min, VIL = 0.8 V max at VCC = 5 V) ensure direct compatibility with legacy 5 V logic families, while CMOS output structure provides rail-to-rail swing and low static current (ICC ≤ 8 μA typical). The device complies with JEDEC JESD8C and JESD7A standards and supports 15 pF load-driven switching up to 33 ns propagation delay.

Key Specifications

Pinout & Package

74HCT244D,653 uses the SO20 (SOT163-1) plastic small outline package: 20-pin, 7.5 mm body width, 1.27 mm pitch, gull-wing leads, JEDEC MS-013 compliant. Thermal resistance θJA = 109 °C/W (typical), Ptot derates linearly at 12.3 mW/K above 109 °C.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74HCT244PW,118 and SN74HCT244N, the 74HCT244D,653 offers optimal balance of manufacturability (standard SO20 reflow), thermal robustness (109 °C/W), and compliance (RoHS, JEDEC), making it the default choice for new industrial and automotive designs requiring surface-mount reliability.

Availability

74HCT244D,653 is available at Aetrix Electronics and suitable for industrial PLC backplanes, automotive body control modules, microcontroller I/O expansion, and legacy instrument cluster interfaces requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for 74HCT244D,653 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 high-volume applications.

The 74HCT244D,653 belongs to Nexperia's industry-standard 74HCT logic family, designed specifically for robust 5 V TTL-to-CMOS interfacing in industrial automation, automotive electronics, and embedded control systems.

FAQ

What is the maximum clock/data rate supported by the 74HCT244D,653?

The 74HCT244D,653 does not operate on a clock; it is a combinatorial buffer. Its usable data rate depends on propagation delay (11 ns typ) and bus loading. With 15 pF load and clean edges, it reliably supports sustained toggle frequencies up to ~45 MHz in point-to-point configurations. For longer traces or higher capacitance, derate based on measured tpd and system timing margins.

Can 74HCT244D,653 be used with a 3.3 V microcontroller?

No - the 74HCT244D,653 requires 4.5 V to 5.5 V VCC and has TTL-level inputs (VIH ≥ 2.0 V). While its inputs may recognize 3.3 V as HIGH, the device itself cannot be powered at 3.3 V. For 3.3 V systems, use 74LVC244A or 74ALVC244 instead, which support 3.3 V operation and have CMOS-compatible inputs.

Is the SO20 package of 74HCT244D,653 RoHS-compliant and lead-free?

Yes - the 74HCT244D,653 (SOT163-1) is manufactured with 100 % matte tin lead finish and fully complies with EU RoHS Directive 2011/65/EU and China RoHS. Nexperia confirms halogen-free epoxy molding compound and lead-free solderability per J-STD-020 Rev. E.

How should unused inputs and outputs be handled?

Unused inputs must be tied HIGH or LOW (preferably to VCC or GND via ≤ 10 kΩ resistor) to prevent floating states and excessive ICC. Unused outputs should be left unconnected - their 3-state behavior ensures no current flow when associated OE is HIGH. Never tie unused outputs directly to VCC or GND.