Texas Instruments SN74AC74PW

Overview

SN74AC74PW from Texas Instruments is a dual positive-edge-triggered D-type flip-flop IC with independent asynchronous clear (CLR) and preset (PRE) inputs per channel, 2V–6V supply operation, ≤10ns propagation delay at 5V, and complementary Q/Q outputs - used in clock division, switch debouncing, and synchronous logic control in industrial control panels and embedded timing circuits.

For engineers reviewing the SN74AC74PW datasheet, SN74AC74PW pinout, SN74AC74PW application, or SN74AC74PW equivalent, this page delivers verified package mapping (TSSOP-14), functional truth table behavior, timing constraints at 3.3V/5V, thermal resistance (R_θJA = 145.7°C/W), and real-world toggle-switch implementation guidance.

Technical Context

The SN74AC74PW implements two fully independent CMOS D-type flip-flops sharing only V_CC and GND rails. Each channel features asynchronous active-low PRE and CLR inputs that override clocked data latching, enabling immediate state initialization without clock dependency.

Its balanced push-pull outputs drive ±24mA at 4.5V with VOH ≥ 3.86V and VOL ≤ 0.44V, while standard CMOS inputs accept up to 6V regardless of V_CC, supporting mixed-voltage interfacing. The device operates across −40°C to +85°C with no default power-on state.

Key Specifications

Pinout & Package

TSSOP-14 (PW) package: 5mm × 6.4mm body with 0.65mm pitch, exposed pad not present - compatible with standard surface-mount reflow profiles and automated optical inspection.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74AC74PW, SN74LVC74APW offers faster switching at 3.3V but sacrifices 5V input tolerance, while 74HC74PW provides robust noise immunity at lower speed - choice depends on voltage architecture, timing budget, and legacy compatibility requirements.

Availability

SN74AC74PW is available at Aetrix Electronics and suitable for industrial control panels, microcontroller peripheral interfaces, and serial-to-parallel data conversion systems requiring stable component supply and long-term manufacturability.

Supply support for SN74AC74PW 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 global semiconductor leader delivering analog, embedded processing, and logic solutions with emphasis on reliability, precision, and broad application coverage.

The SN74AC74PW belongs to TI's AC-series advanced CMOS logic family, designed for high-speed, low-power, mixed-voltage digital interfacing in industrial, automotive, and communications equipment.

FAQ

What is the maximum clock frequency supported by SN74AC74PW at 5V?

The SN74AC74PW supports a maximum clock frequency of 125MHz at V_CC = 5V ± 0.5V, as specified in the Switching Characteristics table. This is derived from t_PLH/t_PHL timing parameters and accounts for worst-case process/voltage/temperature conditions. The SN74AC74PW achieves this while maintaining full setup/hold margins and guaranteed output transitions.

Can SN74AC74PW inputs safely interface with 5V logic while operating at 3.3V V_CC?

Yes, SN74AC74PW inputs tolerate voltages up to 6V regardless of V_CC level - confirmed in the Recommended Operating Conditions and Absolute Maximum Ratings sections. When V_CC = 3.3V, the SN74AC74PW accepts 5V input signals without damage or level-shifting circuitry, making it ideal for bridging 3.3V and 5V subsystems.

Does SN74AC74PW have a defined power-on state for its outputs?

No, the SN74AC74PW has no defined power-on state - the initial Q and Q outputs are indeterminate after power application. To ensure predictable startup, external circuitry (e.g., RC-based power-on reset applied to PRE/CLR pins) must force a known state, as explicitly stated in the Detailed Description section.

What decoupling capacitance is recommended for SN74AC74PW?

A 0.1µF ceramic capacitor placed as close as possible between V_CC and GND pins is recommended for SN74AC74PW, per TI's Layout Guidelines. This minimizes high-frequency supply noise and prevents output instability during fast switching. For enhanced noise rejection, a parallel 1µF capacitor may be added, but the 0.1µF unit remains mandatory and must be physically adjacent to the IC.

Is SN74AC74PW pin-compatible with other 14-pin dual D-flip-flop packages?

SN74AC74PW (TSSOP-14) shares identical pin numbering and function mapping with SN74AC74N (PDIP-14), SN74AC74D (SOIC-14), and SN74AC74DB (SSOP-14), as confirmed in the Pin Configuration and Functions section. However, mechanical dimensions and thermal characteristics differ - PCB layout must match the selected package variant.