Texas Instruments SN74F74NG4

Overview

SN74F74NG4 from Texas Instruments is a dual positive-edge-triggered D-type flip-flop with independent preset and clear inputs, operating over 0°C to 70°C, supporting up to 80 MHz clock frequency, 3 ns minimum setup time for data, and 3.6 ns typical propagation delay (CLK to Q), used in synchronous logic control and state-machine sequencing in industrial control panels.

For engineers reviewing the SN74F74NG4 datasheet, SN74F74NG4 pinout, SN74F74NG4 application, or SN74F74NG4 equivalent, key selection criteria include TTL-compatible input thresholds (VIL = 0.8 V, VIH = 2 V), guaranteed output drive (IOL = 20 mA), dual independent flip-flop architecture with asynchronous controls, and PDIP-14 packaging with through-hole mounting compatibility.

Technical Context

This device implements two fully independent D-type latches, each with dedicated PRE, CLR, CLK, D, Q, and Q̅ terminals. Clock triggering occurs on the positive-going edge at a defined voltage threshold-not dependent on slew rate-enabling robust timing in noisy environments.

Asynchronous preset and clear override clock and data inputs, forcing Q to high or low regardless of CLK/D states. The function table confirms non-overlapping active-low control priority and defines metastability boundaries when both PRE and CLR are simultaneously low.

Key Specifications

Pinout & Package

Packaged in 14-pin plastic dual in-line package (PDIP), SN74F74NG4 features through-hole mounting, 0.3-inch body width, and industry-standard pin spacing (2.54 mm).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LS74AN and SN74HC74N, SN74F74NG4 delivers superior speed-power trade-off for legacy 5 V TTL systems, maintains full pin-and-function compatibility with original F74 designs, and avoids level-shifter overhead required by CMOS alternatives.

Availability

SN74F74NG4 is available at Aetrix Electronics and suitable for industrial control sequencing, digital test equipment, legacy system repair, and education & prototyping requiring stable component supply and long-term obsolescence management.

Supply support for SN74F74NG4 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

Texas Instruments is a U.S.-based semiconductor company founded in 1930, specializing in analog, embedded processing, and logic solutions for industrial, automotive, and communications markets.

The SN74F74NG4 belongs to TI's 74F logic family, designed specifically to deliver high-speed TTL performance with improved noise immunity and reduced propagation delay versus earlier 74LS and 74S series for mission-critical digital control applications.

FAQ

What is the maximum clock frequency supported by SN74F74NG4?

The SN74F74NG4 supports a maximum clock frequency of 80 MHz under recommended operating conditions (VCC = 4.5 V to 5.5 V, TA = 0°C to 70°C). This rating is validated by timing parameter tW (minimum clock pulse width) of 5 ns and fclock maximum specification in the official SDFS046A datasheet. Exceeding this limit risks setup/hold violations and metastability in the SN74F74NG4 flip-flop outputs.

Does SN74F74NG4 support true dual independent operation of its two flip-flops?

Yes, SN74F74NG4 provides two electrically isolated D-type flip-flops with separate PRE, CLR, CLK, D, Q, and Q̅ terminals. No shared internal nodes exist between sections - confirmed by the logic diagram, pinout, and function table in the SDFS046A datasheet. This independence allows SN74F74NG4 to implement concurrent state transitions in different subsystems without crosstalk.

Can SN74F74NG4 be used as a direct replacement for SN74F74N in existing designs?

Yes, SN74F74NG4 is a functionally and pin-compatible variant of SN74F74N, sharing identical PDIP-14 packaging, electrical specifications, timing parameters, and marking ("F74"). The "G4" suffix denotes TI's green packaging standard (lead-free, RoHS-compliant finish), with no impact on SN74F74NG4 logic behavior or AC/DC performance per the official package addendum.

What are the absolute maximum ratings for SN74F74NG4 supply voltage and input voltage?

The absolute maximum supply voltage (VCC) for SN74F74NG4 is –0.5 V to 7 V, and the absolute maximum input voltage (VI) is –1.2 V to 7 V - per the SDFS046A datasheet Absolute Maximum Ratings table. Operation beyond these limits may cause permanent damage. Recommended operating VCC remains 4.5–5.5 V; exceeding 5.5 V voids guaranteed SN74F74NG4 parametric performance.

How does the asynchronous clear (CLR) function behave in SN74F74NG4 when both PRE and CLR are low?

When both PRE and CLR are low in SN74F74NG4, the outputs enter a non-stable state (Q = Q̅ = H), which is explicitly marked as undefined in the function table. The SDFS046A datasheet warns that this condition is not guaranteed to meet VOH specifications and will not persist once either PRE or CLR returns high - confirming that simultaneous assertion violates intended SN74F74NG4 operation and must be avoided in system design.