Nexperia USA Inc. 74HCT280D,653

Overview

74HCT280D,653 from Nexperia is a 9-bit TTL-level odd/even parity generator and checker IC in SO14 package, delivering PE (even parity) and PO (odd parity) outputs with propagation delay of 21–63 ns at VCC = 4.5 V, operating across -40 °C to +125 °C, and used in data integrity verification for industrial bus interfaces and memory subsystems.

For engineers reviewing the 74HCT280D,653 datasheet, 74HCT280D,653 pinout, 74HCT280D,653 application, or 74HCT280D,653 equivalent, key selection criteria include TTL-compatible input thresholds (VIH = 2.0 V min, VIL = 0.8 V max), dual-parity output capability, SO14 thermal derating (10.1 mW/K above 100 °C), and cascading support for >9-bit word expansion.

Technical Context

This device implements combinational logic to count HIGH states across nine inputs (I0–I8) and assert PE when the count is even, PO when odd-no internal clock or state retention. It uses standard CMOS silicon with TTL-level input buffers, enabling direct interfacing with legacy 5 V TTL logic families without level shifters.

Input clamping diodes allow safe operation with input voltages exceeding VCC when current-limited, and the design supports parallel cascading via PE outputs tied to downstream data inputs-enabling scalable parity generation up to 81 bits using nine devices.

Key Specifications

Pinout & Package

74HCT280D,653 is housed in SO14 (SOT108-1) plastic small outline package: 14-pin, 3.9 mm body width, 1.27 mm lead pitch, surface-mountable with gull-wing leads and standard JEDEC MS-012 footprint.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 9-bit parity generator/checker applications.

Compared with 74HC280D,653 and SN74LS280N, the 74HCT280D,653 uniquely balances TTL input compatibility with CMOS power efficiency-making it optimal for modern 5 V industrial controllers needing low standby current and guaranteed TTL signal recognition.

Availability

74HCT280D,653 is available at Aetrix Electronics and suitable for industrial serial bus interfaces, memory subsystem integrity checks, PLC backplanes, and legacy microcontroller peripheral expansion requiring stable component supply across extended temperature ranges.

Supply support for 74HCT280D,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 focused on essential efficiency technologies, delivering high-performance, reliable, and energy-efficient components for automotive, industrial, and consumer applications.

The 74HCT280D,653 belongs to Nexperia's 74HCT logic family-designed specifically to bridge legacy TTL systems with modern low-power CMOS infrastructure while maintaining pin-for-pin compatibility and robust industrial qualification.

FAQ

Can 74HCT280D,653 operate at 3.3 V supply?

No. The 74HCT280D,653 is specified only for 4.5 V to 5.5 V operation per its Recommended Operating Conditions table. At 3.3 V, input thresholds (VIH ≥ 2.0 V) may still be met, but VOH and VOL parameters are not guaranteed, and propagation delay increases significantly-potentially violating timing budgets. Use 74HC280D for 3.3 V systems.

Is the PE output actively driven or open-drain?

The PE output is a standard CMOS totem-pole output-not open-drain. It sources and sinks current (±4.0 mA at VCC = 4.5 V) and swings rail-to-rail. No external pull-up is required, unlike true open-drain parity generators. This simplifies board layout and reduces component count.

How many 74HCT280D,653 devices can be cascaded for parity expansion?

Up to nine devices can be cascaded: the PE output of each feeds one of the nine inputs (I0–I8) of the next stage. This supports up to 81-bit parity generation. Beyond nine, fan-out limitations and cumulative propagation delay (>600 ns worst-case) degrade timing margins-additional buffering or synchronous alignment is required.

Does 74HCT280D,653 support live insertion in hot-swap backplanes?

Yes-input clamping diodes and ±20 mA input clamping current rating (per Table 4) enable safe hot-insertion when series current-limiting resistors are used on all I0–I8 lines. However, VCC and GND must make contact before signal pins; follow Nexperia's SOT108-1 mechanical insertion sequence to prevent latch-up.