NXP Semiconductors 74HCT280D,652

Overview

74HCT280D,652 from Nexperia is a 9-bit TTL-level odd/even parity generator and checker IC in SO14 (SOT108-1) package, delivering PE (even parity) and PO (odd parity) outputs with propagation delays as low as 21 ns at VCC = 4.5 V, used for error detection in parallel data buses and memory subsystems.

For engineers reviewing the 74HCT280D,652 datasheet, 74HCT280D,652 pinout, 74HCT280D,652 application, or 74HCT280D,652 equivalent, this device supports cascaded parity expansion up to 17+ bits, operates across -40 °C to +125 °C, and provides CMOS-compatible output drive with TTL input thresholds.

Technical Context

The 74HCT280D,652 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 latching or clocking required. It uses standard TTL input voltage thresholds (VIH ≥ 2.0 V, VIL ≤ 0.8 V at VCC = 4.5–5.5 V), enabling direct interface with legacy 5 V logic families.

Its static output drive capability delivers VOH ≥ 3.98 V at IO = −4.0 mA and VOL ≤ 0.26 V at IO = 4.0 mA under recommended conditions, while dynamic performance includes tpd ≤ 42 ns (max, −40 °C to +85 °C) and transition times ≤ 19 ns, verified with CL = 50 pF loads.

Key Specifications

Pinout & Package

74HCT280D,652 is housed in a plastic small outline package (SO14, SOT108-1) with 14 leads and 3.9 mm body width, optimized for automated PCB assembly and thermal reliability in dense layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74HC280D,652 and SN74LS280N, the 74HCT280D,652 uniquely balances TTL input compatibility, low power (≤160 μA), and industrial temperature support - making it optimal for new designs requiring robust, drop-in parity checking without voltage translation.

Availability

74HCT280D,652 is available at Aetrix Electronics and suitable for memory subsystems, industrial PLCs, legacy system upgrades, and RS-485 communication interfaces requiring stable component supply across extended temperature ranges.

Supply support for 74HCT280D,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 efficiency technologies, delivering high-performance, reliable logic, analog, and discrete components for automotive, industrial, and consumer markets.

The 74HCT280D,652 belongs to Nexperia's 74HCT logic family, engineered specifically to bridge TTL and CMOS domains with robust noise immunity, wide temperature operation, and low-power static consumption.

FAQ

Can 74HCT280D,652 operate at 3.3 V supply?

No. The 74HCT280D,652 is specified only for VCC = 4.5 V to 5.5 V per its HCT-series TTL-input architecture. At 3.3 V, VIH threshold (2.0 V min) may not be reliably met by 3.3 V logic outputs, risking incorrect parity evaluation. Use 74HC280D,652 instead for 3.3 V systems.

How is cascading implemented for larger word sizes?

Cascading uses the PE (even parity) output of one device as a data input to a second device's I0–I8 pins. For example, two 74HCT280D,652 units generate 18-bit parity: first processes bits 0–8, second processes bits 9–17 plus the first's PE output as bit 18 - final PE/PO reflects overall parity.

What is the maximum fan-out when driving 74HCT280D,652 inputs?

Each input presents ≤1 TTL unit load (20 μA IIH, −0.4 mA IIL). The device can drive ≥10 standard LS-TTL inputs (or ≥20 HCT inputs) directly due to its VOH ≥ 3.98 V @ −4.0 mA and VOL ≤ 0.26 V @ 4.0 mA, verified across −40 °C to +125 °C.

Does 74HCT280D,652 require external pull-up or pull-down resistors?

No. All nine inputs (I0–I8) have internal clamp diodes and defined VIH/VIL thresholds; floating inputs are undefined and must be actively driven HIGH or LOW. Unused inputs should be tied to GND or VCC - no pull resistors needed for proper function.