NXP Semiconductors 74HCT7273N,112

Overview

74HCT7273N,112 from NXP Semiconductors (formerly Philips) is an octal D-type flip-flop with asynchronous master reset, positive edge-triggered clock, and open-drain N-type outputs. It operates at 4.5–5.5 V, delivers 56 MHz maximum clock frequency, features 16 ns CP-to-Q propagation delay, and is pin-compatible with LSTTL. It serves as a level-shifting buffer in microprocessor address/data bus latching and memory interface circuits.

For engineers reviewing the 74HCT7273N,112 datasheet, 74HCT7273N,112 pinout, 74HCT7273N,112 application, or 74HCT7273N,112 equivalent, key selection criteria include open-drain output compatibility with mixed-voltage systems, guaranteed setup/hold timing (12 ns / 3 ns), MR pulse width tolerance (8 ns min), and DIP-20 package suitability for through-hole prototyping and industrial control PCBs.

Technical Context

The 74HCT7273N,112 implements eight independent D-type storage elements sharing a single LOW-to-HIGH edge-triggered clock (CP) and active-LOW asynchronous master reset (MR). Each flip-flop samples its Dn input one setup time before the CP rising edge and transfers the value to its corresponding Qn output - which enters high-impedance (Z) state when '1' is clocked and drives LOW when '0' is clocked.

Its open-drain outputs require external pull-up resistors and support bidirectional level shifting between GND and VOmax (≤VCC), enabling OR-tied bus structures and interfacing with 3.3 V or 5 V logic families. The device complies with JEDEC Standard No. 7A and exhibits ESD robustness exceeding 2000 V HBM.

Key Specifications

Pinout & Package

Dual In-line Package (DIP-20), plastic body, 300-mil width, through-hole mount (SOT146-1). Pin 1 index marked by notch or dot; seating plane defined per JEDEC MS-001.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal D-type flip-flop with reset applications.

Compared with 74HCT7273N,112, the 74HCT374N,112 trades MR for OE and loses open-drain capability, while SN74HCT574N retains identical timing but removes level-shifting utility - making 74HCT7273N,112 uniquely suited for voltage-domain bridging and bus arbitration.

Availability

74HCT7273N,112 is available at Aetrix Electronics and suitable for industrial control systems, embedded microcontroller peripherals, and legacy hardware repair requiring stable component supply and long-term DIP-20 availability.

Supply support for 74HCT7273N,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

NXP Semiconductors is a global semiconductor leader focused on secure connectivity solutions for automotive, industrial, and IoT applications.

The 74HCT7273N,112 belongs to the legacy 74HCT logic family designed for TTL-compatible, high-noise-immunity digital interfacing in industrial and instrumentation systems.

FAQ

What is the function of the MR pin on the 74HCT7273N,112?

The MR (Master Reset) pin on the 74HCT7273N,112 is an asynchronous active-LOW input that forces all eight Qn outputs to LOW regardless of clock or data state. Its minimum pulse width is 8 ns at VCC = 4.5 V, and it overrides all other inputs - including CP and Dn - ensuring immediate, deterministic reset across all flip-flops in the 74HCT7273N,112 device.

Can the 74HCT7273N,112 be used with a 3.3 V microcontroller?

Yes, the 74HCT7273N,112 supports mixed-voltage operation: its inputs are 5 V tolerant (VIH = 2.0 V min), and its open-drain outputs can be pulled up to 3.3 V. When used with a 3.3 V controller, connect the pull-up resistor to 3.3 V and ensure CP and Dn signals meet 74HCT7273N,112's VIH/VIL thresholds - enabling safe, bidirectional level translation without additional components.

Does the 74HCT7273N,112 require external pull-up resistors on its outputs?

Yes, the 74HCT7273N,112 has open-drain N-type outputs and cannot source current. A pull-up resistor must be connected between each Qn pin and a positive supply (e.g., 3.3 V or 5 V) to establish a valid HIGH logic level. Typical values range from 1 kΩ to 10 kΩ depending on speed and fanout requirements - critical for correct operation of the 74HCT7273N,112 in bus or level-shifting configurations.

What is the maximum clock frequency supported by the 74HCT7273N,112?

The 74HCT7273N,112 supports a maximum clock frequency of 56 MHz at VCC = 4.5 V and Tamb = 25 °C. At extended temperature ranges (−40 to +125 °C), the guaranteed fmax drops to 20 MHz. This rating applies only when setup (12 ns) and hold (3 ns) timing constraints are met - essential for reliable data capture in high-speed 74HCT7273N,112 deployments.

Is the 74HCT7273N,112 pin-compatible with older TTL devices?

Yes, the 74HCT7273N,112 is explicitly designed to be pin-compatible with Low Power Schottky TTL (LSTTL) octal D-type flip-flops and complies with JEDEC Standard No. 7A. Its DIP-20 footprint (SOT146-1), pin assignments (e.g., MR on pin 1, CP on pin 11, Q0–Q7 on pins 2/5/6/9/12/15/16/19), and electrical interface allow direct replacement of legacy 74LS7273 in existing designs without PCB modification - a core feature of the 74HCT7273N,112.