Texas Instruments SN74F74NSR

Overview

SN74F74NSR 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 80 MHz maximum clock frequency at 5 V, with 3 ns typical propagation delay (CLK→Q), and designed for synchronous logic control in digital state machines and data latching applications.

For engineers reviewing the SN74F74NSR datasheet, SN74F74NSR pinout, SN74F74NSR application, or SN74F74NSR equivalent, key selection considerations include its SOP-14 package, TTL-compatible input thresholds, guaranteed setup/hold timing (2 ns/1 ns), rail-to-rail output swing under 20 mA load, and direct compatibility with legacy 74F logic families in industrial control and instrumentation systems.

Technical Context

This device implements two fully independent D-type latches triggered on the rising edge of CLK, each with asynchronous active-low PRE and CLR inputs that override clocked operation. Each flip-flop features complementary Q and Q̅ outputs, enabling direct implementation of toggle, register, or set/reset memory elements without external inversion.

Logic behavior follows strict positive-edge sampling: data at D is captured only on CLK's rising transition when both PRE and CLR are high; low PRE forces Q = H / Q̅ = L, low CLR forces Q = L / Q̅ = H, and simultaneous low PRE/CLR yields undefined (non-latched) outputs per functional table. Clock triggering is voltage-level–based-not slew-rate–dependent-ensuring robust operation across varying signal rise times.

Key Specifications

Pinout & Package

SOP-14 (NS package), 1.75 mm max height, 12×1.27 mm body, 0.65 mm lead pitch, RoHS-compliant NiPdAu finish, moisture sensitivity level 1 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LS74N, SN74F74NSR delivers 2.7× higher clock rate and 5× lower propagation delay, making it essential for timing-critical control; versus SN74ACT74DR, it retains TTL input thresholds and stronger output drive-advantageous in legacy 5 V systems with marginal signal integrity.

Availability

SN74F74NSR is available at Aetrix Electronics and suitable for industrial control panels, test instrumentation, and legacy 5 V digital systems requiring stable component supply and long-term obsolescence management.

Supply support for SN74F74NSR 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 SN74F74NSR belongs to TI's 74F (Fast TTL) logic family, engineered for high-speed digital control in commercial-grade systems where performance, reliability, and backward compatibility with 74-series standards are critical.

FAQ

What is the maximum clock frequency supported by the SN74F74NSR?

The SN74F74NSR supports a maximum clock frequency of 80 MHz under recommended operating conditions (VCC = 5 V, TA = 25°C). This rating is validated by TI's switching characteristics table and applies specifically to the SN74F74NSR in SOP-14 package. At temperature extremes (0°C or 70°C), derating may apply per the full datasheet timing curves.

Does the SN74F74NSR have built-in Schmitt-trigger inputs for noisy clock signals?

No, the SN74F74NSR does not include Schmitt-trigger inputs. Its clock input (CLK) responds to voltage-level thresholds-not hysteresis-and is specified for standard TTL-compatible waveforms. For noisy environments, external RC filtering or a dedicated Schmitt-trigger buffer (e.g., SN74F14) should precede the CLK input of SN74F74NSR.

Can both flip-flops in the SN74F74NSR be reset simultaneously using a single control line?

Yes - connect the same active-low signal to both Pin 1 (1CLR) and Pin 9 (2CLR) to assert asynchronous clear on both flip-flops concurrently. The SN74F74NSR's dual CLR inputs are electrically isolated but functionally identical, allowing coordinated reset without timing skew between channels.

Is the SN74F74NSR pin-compatible with the SN74LS74N in the same SOP-14 footprint?

No - the SN74F74NSR uses SOP-14 (NS) package, while SN74LS74N is typically offered in PDIP-14 (N) or SOIC-14 (D) packages. Though both are 14-pin dual D-flip-flops with identical pin functions, the NS and D packages differ in lead pitch (0.65 mm vs. 1.27 mm) and body dimensions; mechanical interchangeability is not guaranteed without layout verification.

What is the purpose of the NC pins on the SN74F74NSR?

The SN74F74NSR has no NC (No Connect) pins - all 14 pins are assigned functional roles per the official TI pinout diagram. Any reference to NC in older 74F74 documentation applies to ceramic or military variants (e.g., FK or J packages); the SOP-14 SN74F74NSR utilizes every pin for signal, power, or ground connectivity.