Texas Instruments SN74ACT374DB

Overview

SN74ACT374DB from Texas Instruments is an octal D-type edge-triggered flip-flop with 3-state outputs, designed for bus-oriented digital systems. It operates at 4.5–5.5 V, delivers 10 ns max propagation delay at 5 V, supports TTL-voltage-compatible inputs, and drives highly capacitive or low-impedance loads in I/O port and buffer register applications.

For engineers reviewing the SN74ACT374DB datasheet, SN74ACT374DB pinout, SN74ACT374DB application, or SN74ACT374DB equivalent, this page provides verified functional behavior, validated SSOP-20 package mapping, confirmed timing parameters (t_PLH/t_PHL ≤ 11.5 ns), and real-world use cases in bidirectional bus driving and working register implementation.

Technical Context

The SN74ACT374DB implements eight independent D-type flip-flops, each triggered on the positive edge of CLK. Its buffered OE input controls all eight outputs simultaneously, enabling high-impedance state without affecting internal latch operation - allowing data retention or new sampling while outputs are disabled.

It features TTL-compatible input thresholds (V_IL = 0.8 V, V_VIH = 2 V), rail-to-rail output swing (V_OH ≥ 3.7 V at I_OH = −24 mA), and guaranteed 24 mA sink/source capability per output - making it suitable for direct interfacing with legacy TTL and modern CMOS buses without level-shifting components.

Key Specifications

Pinout & Package

SN74ACT374DB is housed in a 20-pin SSOP (Shrink Small Outline Package) with 0.65 mm lead pitch, 7.2 mm × 7.8 mm body dimensions, and 2.0 mm maximum height - optimized for high-density PCB layouts while maintaining hand-solderability and reflow compatibility (MSL Level-1).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal D-type latch applications.

Compared with SN74ACT574DBR and 74LVX374M, the SN74ACT374DB uniquely balances 5 V bus compatibility, edge-triggered determinism, and 24 mA drive in a compact SSOP package - making it the preferred choice for industrial 5 V control interfaces where timing predictability and robustness outweigh low-voltage operation.

Availability

SN74ACT374DB is available at Aetrix Electronics and suitable for industrial PLC I/O modules, legacy bus interface adapters, automated test fixture controllers, and digital pattern generators requiring stable component supply across extended product lifecycles.

Supply support for SN74ACT374DB 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 specializing in analog, embedded processing, and logic solutions with over 50 years of innovation in industrial, automotive, and communications markets.

The SN74ACT374DB belongs to TI's ACT (Advanced CMOS Technology) logic family - engineered for high-speed, low-noise 5 V digital interfacing in mission-critical industrial control and instrumentation systems.

FAQ

What is the maximum clock frequency supported by the SN74ACT374DB?

The SN74ACT374DB supports a maximum clock frequency of 90 MHz under recommended operating conditions (V_CC = 5 V, T_A = −40°C to 85°C). This is derived from its guaranteed 5 ns minimum clock pulse width and 11.5 ns maximum propagation delay, ensuring reliable edge-triggered operation in high-speed synchronous systems. The SN74ACT374DB maintains this performance without derating across its full industrial temperature range.

Does the SN74ACT374DB require external pull-up resistors on the OE pin?

Yes - to ensure defined high-impedance state during power-up and power-down sequences, the OE pin of the SN74ACT374DB must be tied to V_CC through an external pullup resistor. TI specifies this as mandatory for predictable bus behavior; the minimum resistance value depends on the current-sinking capability of the driving source, typically 4.7 kΩ to 10 kΩ for standard logic drivers.

Can the SN74ACT374DB interface directly with 3.3 V microcontrollers?

Yes - the SN74ACT374DB accepts input voltages up to V_CC (5.5 V max) and has TTL-compatible thresholds (V_IL = 0.8 V, V_IH = 2.0 V), allowing safe connection to 3.3 V CMOS outputs without level shifters. However, its outputs swing rail-to-rail (0–5 V), so interfacing with 3.3 V–only inputs requires external clamping or voltage translation to avoid overvoltage damage.

What is the thermal resistance (R_θJA) of the SN74ACT374DB in its SSOP package?

The SN74ACT374DB in DB (SSOP-20) package has a junction-to-ambient thermal resistance (R_θJA) of 70°C/W under standard JEDEC test conditions. This value assumes a 1-inch² copper pad with two vias; actual board-level performance may improve with enhanced thermal land patterns or airflow, supporting continuous operation at full drive strength in ambient temperatures up to 85°C.

How does the SN74ACT374DB handle unused input pins?

All unused input pins on the SN74ACT374DB - including D inputs, CLK, and OE - must be externally biased to either V_CC or GND to prevent floating states that cause excessive current draw, logic instability, or EMI susceptibility. TI explicitly mandates this in Section 4.2 of the datasheet; leaving any input unconnected violates recommended operating conditions and risks device malfunction in industrial environments.