Texas Instruments SN74AHCT74PWRG4

Overview

SN74AHCT74PWRG4 from Texas Instruments is a dual positive-edge-triggered D-type flip-flop with independent asynchronous clear (CLR) and preset (PRE) inputs, operating at 4.5–5.5 V supply, delivering ±8-mA output drive, TTL-compatible input thresholds, and propagation delays as low as 5.8 ns (CL = 15 pF) - used for clock division, signal debouncing, and synchronous state retention in industrial control logic.

For engineers reviewing the SN74AHCT74PWRG4 datasheet, SN74AHCT74PWRG4 pinout, SN74AHCT74PWRG4 application, or SN74AHCT74PWRG4 equivalent, key selection considerations include its TSSOP-14 package footprint, 5-V-only operation, guaranteed setup/hold timing (tsu = 5 ns, th = 0 ns), and compatibility with legacy TTL-level driving sources in noise-immune digital interfaces.

Technical Context

The SN74AHCT74PWRG4 implements two independent edge-triggered D flip-flops sharing no internal coupling; each features active-low asynchronous PRE and CLR that override clock and data, enabling immediate state initialization. Clock triggering occurs at a fixed voltage threshold (~1.4 V), decoupled from input slew rate - supporting reliable operation with slow-rising or noisy clock edges.

Its balanced CMOS push-pull outputs provide symmetrical sourcing/sinking capability (±8 mA @ 5 V), while TTL-compatible inputs accept standard 0.8 V/2.0 V logic thresholds and tolerate up to 20 ns/V input transition rates. The device exhibits latch-up immunity exceeding 250 mA per JESD17 and operates across –40°C to +125°C ambient temperature.

Key Specifications

Pinout & Package

PW package: 14-pin TSSOP (5.0 mm × 6.4 mm body, 0.65 mm pitch), thermally enhanced with exposed pad (not electrically connected).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC74APWR and 74HC74PW,118, the SN74AHCT74PWRG4 uniquely guarantees TTL-level input recognition and 5-V-only operation - making it the only choice for direct replacement in legacy 5-V systems with LS/F-series logic or unbuffered microcontroller outputs.

Availability

SN74AHCT74PWRG4 is available at Aetrix Electronics and suitable for industrial automation controllers, automotive body electronics, and test equipment requiring stable component supply, long-term lifecycle support, and guaranteed 5-V logic interoperability.

Supply support for SN74AHCT74PWRG4 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 specializing in analog, embedded processing, and logic solutions, with leadership in industrial, automotive, and communications markets.

The SN74AHCT74PWRG4 belongs to TI's AHCT logic family - designed specifically for seamless 5-V TTL-to-CMOS bridging in legacy system upgrades and noise-prone industrial interfaces.

FAQ

What is the maximum clock frequency supported by the SN74AHCT74PWRG4?

The SN74AHCT74PWRG4 supports a maximum clock frequency of 100 MHz under typical conditions (CL = 15 pF, TA = 25°C), based on its 5.8-ns tPLH propagation delay. At elevated temperatures or heavier capacitive loads (e.g., CL = 50 pF), the practical limit drops to 80 MHz. This makes the SN74AHCT74PWRG4 suitable for medium-speed synchronous logic but not for GHz-range applications.

Can the SN74AHCT74PWRG4 operate at 3.3 V?

No, the SN74AHCT74PWRG4 cannot operate reliably at 3.3 V. Its recommended operating voltage is strictly 4.5 V to 5.5 V, and its TTL-compatible inputs require VIH ≥ 2.0 V - which is insufficiently guaranteed below 4.5 V. Attempting 3.3-V operation risks undefined output states, increased ICC, and potential latch-up. Use SN74LVC74APWR instead for 3.3-V systems.

How should unused inputs be handled on the SN74AHCT74PWRG4?

All unused inputs on the SN74AHCT74PWRG4 - including PRE, CLR, D, and CLK - must be terminated to either VCC or GND. Floating inputs cause excessive ICC, erratic switching, and potential oscillation due to TTL-compatible input structure sensitivity. TI recommends 10-kΩ pull-up or pull-down resistors for inputs that may be left unconnected during certain modes, but direct connection is preferred for permanently unused pins.

Does the SN74AHCT74PWRG4 have built-in ESD protection?

Yes, the SN74AHCT74PWRG4 includes integrated ESD protection rated per JEDEC standards: ±2000 V HBM and ±1000 V CDM. This meets typical board-level handling requirements but does not eliminate the need for proper ESD-safe practices during assembly. The device also features internal clamp diodes on all inputs and outputs to shunt transient overvoltage, provided current limits (±20 mA) are respected per Absolute Maximum Ratings.

Is the SN74AHCT74PWRG4 pin-compatible with other 74xx74 variants in TSSOP-14?

Yes, the SN74AHCT74PWRG4 shares identical pinout and footprint with all industry-standard 74xx74 dual D-type flip-flops in PW (TSSOP-14) packaging, including SN74LVC74APWR and 74HC74PW,118. However, electrical differences - especially supply voltage range, input thresholds, and output drive - mean direct substitution requires verification of system-level voltage and timing compatibility. The SN74AHCT74PWRG4 is not a drop-in replacement for 3.3-V-only variants.