Texas Instruments SN74HCT374ANSR

Overview

SN74HCT374NSR from Texas Instruments is an octal edge-triggered D-type flip-flop IC with 3-state outputs, operating at 4.5–5.5 V, delivering ±6-mA output drive, 22-ns typical propagation delay, and 80-μA max ICC. It serves as a bus-oriented register in digital I/O interfaces and bidirectional data buffering.

For engineers reviewing the SN74HCT374NSR datasheet, SN74HCT374NSR pinout, SN74HCT374NSR application, or SN74HCT374NSR equivalent, key selection criteria include TTL-compatible inputs, high-current 3-state outputs capable of driving 15 LSTTL loads, positive-edge clock triggering, and compatibility with 5-V logic systems requiring bus isolation.

Technical Context

The SN74HCT374NSR implements eight independent D-type flip-flops synchronized to the rising edge of CLK, with each Q output latching the corresponding D input state at clock transition. Its 3-state outputs are controlled by a common OE input, enabling high-impedance mode without affecting internal latch states.

This device uses HCMOS-compatible circuitry with TTL-voltage-level inputs (VIH = 2 V, VIL = 0.8 V), operates within −40°C to +85°C, and features low input current (≤1 μA) and low power consumption-critical for stable 5-V digital interface design where bus contention and signal integrity must be avoided.

Key Specifications

Pinout & Package

SOP-20 (NS) package: 15.00 mm × 5.30 mm body, 1.27 mm pitch, 2.65 mm max height, RoHS-compliant NIPDAU lead finish, 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 SN74HCT574NSR and 74ACT374MTCX, the SN74HCT374NSR offers optimal balance of TTL interoperability, low power, and single-group 3-state control - making it ideal for general-purpose 5-V bus buffering where pin compatibility and legacy integration are priorities.

Availability

SN74HCT374NSR is available at Aetrix Electronics and suitable for industrial I/O expansion, microcontroller bus interface, and legacy system emulation requiring stable component supply and long-term production continuity.

Supply support for SN74HCT374NSR 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 and automotive electronics.

The SN74HCT374NSR belongs to TI's 74HCT logic family, designed for 5-V mixed-signal systems requiring TTL-compatible inputs, low power, and robust bus-driving capability in industrial control and instrumentation.

FAQ

What is the maximum clock frequency supported by the SN74HCT374NSR?

The SN74HCT374NSR supports a maximum clock frequency of 25 MHz under recommended operating conditions (VCC = 4.5–5.5 V, TA = −40°C to +85°C). This is derived from its minimum clock pulse width (tw = 20 ns) and verified switching characteristics at CL = 150 pF. The SN74HCT374NSR achieves this timing while maintaining full 3-state control and TTL input compatibility.

Does the SN74HCT374NSR require external pull-up resistors on its outputs?

No, the SN74HCT374NSR does not require external pull-up resistors. Its high-current 3-state outputs provide ±6 mA drive capability at 5 V and are designed to directly drive 15 LSTTL loads. When OE is asserted, outputs enter high-impedance mode without leakage or contention - eliminating the need for pull-ups in properly terminated bus systems.

Is the SN74HCT374NSR compatible with 3.3-V logic inputs?

No, the SN74HCT374NSR is not guaranteed compatible with 3.3-V logic inputs. Its input thresholds are TTL-defined (VIH = 2.0 V min, VIL = 0.8 V max), and while some 3.3-V CMOS outputs may meet VIH, the device lacks explicit 3.3-V input characterization. For mixed-voltage systems, level-shifting or a 74LVC374 variant is recommended instead of relying on marginal compatibility of the SN74HCT374NSR.

What is the purpose of the OE pin on the SN74HCT374NSR?

The OE (output-enable) pin on the SN74HCT374NSR is an active-low control that places all eight Q outputs simultaneously into high-impedance state when high. It does not affect internal flip-flop operation - data can be latched or retained regardless of OE state. This enables safe sharing of a common bus among multiple devices, preventing contention during read/write cycles in the SN74HCT374NSR-based system.

Can the SN74HCT374NSR operate outside the −40°C to +85°C range?

The SN74HCT374NSR is characterized and specified only for operation from −40°C to +85°C. While the absolute maximum junction temperature is 150°C, operation outside the rated range risks parametric shift, increased ICC, timing violations, or latch-up. For extended temperature applications, consider the military-grade SN54HCT374J (−55°C to +125°C), not the commercial SN74HCT374NSR.