Texas Instruments SN74AHCT374DBRG4

Overview

SN74AHCT374DBRG4 from Texas Instruments is an octal edge-triggered D-type flip-flop with 3-state outputs, designed for synchronous data latching and bus interface in 5V digital systems. It operates from 4.5V to 5.5V V_CC, delivers 10.5ns propagation delay at 5V/15pF, supports up to 80MHz operation, and features TTL-compatible inputs for seamless legacy logic interfacing - used in parallel data storage and bidirectional bus buffering.

For engineers reviewing the SN74AHCT374DBRG4 datasheet, SN74AHCT374DBRG4 pinout, SN74AHCT374DBRG4 application, or SN74AHCT374DBRG4 equivalent, key selection criteria include its 20-pin SSOP (DB) package, shared rising-edge CLK and active-low OE control, 3-state output drive capability (±25mA), latch-up immunity (>250mA), and compatibility with 5V CMOS/TTL signal domains.

Technical Context

The SN74AHCT374DBRG4 implements eight independent D-type flip-flops sharing a single clock input (CLK) and one active-low output enable (OE). Each channel captures D-input state on the rising edge of CLK, while OE independently places all Q outputs into high-impedance mode without affecting internal latch states.

Its balanced CMOS 3-state outputs provide symmetrical sourcing/sinking capability (±25mA), enabling direct drive of capacitive buses up to 50pF. Input structure includes TTL-compatible thresholds (V_IL = 0.8V, V_IH = 2.0V at V_CC = 4.5–5.5V) and integrated negative clamping diodes per JESD 17 latch-up compliance.

Key Specifications

Pinout & Package

SN74AHCT374DBRG4 is packaged in a 20-pin SSOP (Shrink Small Outline Package) with body dimensions 7.50mm × 5.3mm and overall footprint 7.2mm × 7.8mm. Pin numbering follows standard top-view orientation with pin 1 at bottom-left corner.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74AHCT374DBRG4, SN74AHCT574PW offers identical functionality in a different SSOP-compatible package, while 74LVC374ADB trades 5V/TTL compatibility for higher speed and lower voltage operation - making SN74AHCT374DBRG4 the optimal choice for legacy 5V bus integrity and interoperability.

Availability

SN74AHCT374DBRG4 is available at Aetrix Electronics and suitable for parallel data synchronization, bus interface buffering, and programmable logic I/O expansion requiring stable component supply and long-term industrial availability.

Supply support for SN74AHCT374DBRG4 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 for industrial, automotive, and communications markets.

The SN74AHCT374DBRG4 belongs to TI's AHCT logic family - engineered for 5V TTL/CMOS interoperability, high noise immunity, and robust bus-driving capability in industrial control and instrumentation systems.

FAQ

What is the maximum clock frequency supported by the SN74AHCT374DBRG4?

The SN74AHCT374DBRG4 supports up to 80MHz operation under recommended conditions (V_CC = 5V, C_L = 15pF). At 50pF load, maximum frequency drops to 75MHz. These values are measured with 50% duty cycle clock input and reflect guaranteed performance across –40°C to +85°C operating temperature range. The SN74AHCT374DBRG4 achieves this via optimized CMOS gate design and low-propagation-delay architecture.

Does the SN74AHCT374DBRG4 require external pull-up resistors on unused inputs?

Yes - all unused inputs of the SN74AHCT374DBRG4 must be terminated to either V_CC or GND to prevent floating states that cause excessive current draw, oscillation, or reliability degradation. A 10kΩ pull-up or pull-down resistor is recommended for uncommitted inputs. This requirement stems from its TTL-compatible CMOS input structure, which exhibits high impedance and sensitivity to slow or undefined transitions.

Can the SN74AHCT374DBRG4 drive a 50pF capacitive load reliably?

Yes - the SN74AHCT374DBRG4 is fully characterized for 50pF loads, with switching specifications (t_PLH, t_PHL, t_PZH, etc.) guaranteed under those conditions. Its balanced 3-state outputs deliver ±25mA drive strength, ensuring fast edge rates and minimal distortion into typical PCB traces and multiple CMOS inputs. Exceeding 50pF may degrade timing margins and increase ground bounce, so layout optimization is advised for heavier loads.

Is the SN74AHCT374DBRG4 pin-compatible with other members of the SN74AHCTxx374 family?

Yes - the SN74AHCT374DBRG4 shares identical pinout and function with all SN74AHCT374 variants across packages (e.g., PW, DW, N, DB, DGS, RKS), including SN74AHCT574. Differences are limited to package-specific mechanical features (e.g., thermal pad in RKS) and thermal metrics. Electrical behavior, timing, and logic function remain consistent, enabling drop-in replacement across DB, PW, and SOIC variants when board layout permits.

What is the purpose of the OE (output enable) pin on the SN74AHCT374DBRG4?

The OE pin on the SN74AHCT374DBRG4 is an active-low control that places all eight Q outputs simultaneously into high-impedance state when asserted (low), or enables normal logic-level output (high/low) when deasserted (high). Critically, OE does not affect internal flip-flop operation - data can be latched or retained regardless of OE state. This allows independent data capture and bus release, essential for shared-data-bus architectures like memory-mapped I/O or multiplexed peripheral interfaces.