Texas Instruments SN74ALS374ANSR

Overview

SN74ALS374ANSR from Texas Instruments is an octal D-type edge-triggered flip-flop with 3-state outputs, designed for bus interface and register applications in TTL-compatible digital systems. It operates from 0°C to 70°C, features 20-pin SOP (NS) packaging, supports 35 MHz clock frequency, provides ±24 mA output drive, and enables high-impedance bus isolation via buffered OE control.

For engineers reviewing the SN74ALS374ANSR datasheet, SN74ALS374ANSR pinout, SN74ALS374ANSR application, or SN74ALS374ANSR equivalent, key selection criteria include its ALS logic family timing (tPLH/tPHL ≤12 ns), 3-state output current capability (IOL = 24 mA), thermal performance (θJA = 69°C/W for NS package), and compatibility with legacy 5-V TTL bus architectures requiring latch-and-drive functionality.

Technical Context

This device implements eight independent D-type latches triggered on the positive clock edge, with synchronous data capture and asynchronous 3-state output control. Its buffered OE input isolates outputs without affecting internal state retention, enabling concurrent data loading while maintaining bus integrity.

The SN74ALS374ANSR belongs to the ALS (Advanced Low-Power Schottky) logic family, delivering lower power consumption than standard LS TTL while maintaining compatible voltage thresholds (VIH = 2 V, VIL = 0.8 V) and improved speed over 74LS series. It is not a CMOS device and requires 5-V supply only.

Key Specifications

Pinout & Package

SN74ALS374ANSR uses a 20-pin Small Outline Package (SOP-20, package code NS), 12.6 mm × 7.5 mm body size, 1.27 mm pitch, with pin 1 located in quadrant Q1 per tape-and-reel orientation standard.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74ALS374ANSR, SN74ALS374AN offers identical logic behavior in a through-hole package for ease of validation, while SN74AS374N trades power efficiency for raw speed - making SN74ALS374ANSR optimal for cost-sensitive, thermally constrained 5-V TTL bus interfaces requiring reliable 35 MHz operation.

Availability

SN74ALS374ANSR is available at Aetrix Electronics and suitable for industrial control panels, legacy computer peripherals, and embedded instrumentation requiring stable component supply with long-term lifecycle support.

Supply support for SN74ALS374ANSR 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 SN74ALS374ANSR belongs to TI's legacy TTL logic portfolio, engineered specifically for robust 5-V bus interfacing, register storage, and I/O expansion in industrial and computing systems where reliability and backward compatibility are critical.

FAQ

What is the maximum clock frequency supported by the SN74ALS374ANSR?

The SN74ALS374ANSR supports a maximum clock frequency of 35 MHz under recommended operating conditions (VCC = 4.5 V to 5.5 V, TA = 0°C to 70°C). This value is validated per the SDAS167C datasheet and reflects guaranteed timing performance - not typical or best-case lab measurement. Exceeding 35 MHz may result in setup/hold violations or metastability.

Does the SN74ALS374ANSR support mixed-voltage operation or 3.3-V logic levels?

No, the SN74ALS374ANSR is strictly a 5-V TTL device and does not support 3.3-V operation. Its input thresholds (VIH = 2 V, VIL = 0.8 V) and output voltages (VOH ≥ 2.4 V at IOL = 24 mA) are specified only for VCC = 4.5 V to 5.5 V. Direct connection to 3.3-V systems requires level-shifting circuitry to prevent damage or incorrect logic interpretation.

How does the OE pin behave during power-up or brown-out conditions?

The OE pin on the SN74ALS374ANSR is not internally pulled up or down; it is a standard TTL input. During power-up or brown-out, OE must be actively driven low (≤0.8 V) to ensure outputs remain enabled and avoid undefined high-impedance states that could cause bus contention. External pull-down resistors or controlled reset sequencing are recommended for robust system initialization.

Can the SN74ALS374ANSR be used as a level shifter between different logic families?

No, the SN74ALS374ANSR is not designed or characterized as a level shifter. While its inputs accept standard TTL thresholds and outputs drive 5-V logic levels, it lacks bidirectional voltage translation, slew rate control, or isolation features required for safe level shifting. Use dedicated level translators (e.g., TXB0108) instead for interfacing 3.3-V and 5-V domains.

What is the thermal resistance (θJA) of the SN74ALS374ANSR in its SOP-20 (NS) package?

The junction-to-ambient thermal resistance (θJA) for the SN74ALS374ANSR in the SOP-20 (NS) package is 69°C/W, as specified in the absolute maximum ratings table of the SDAS167C datasheet. This value assumes standard JEDEC high-K test board conditions; actual PCB layout, copper area, and airflow will affect real-world thermal performance.