Texas Instruments SN74BCT374N

Overview

SN74BCT374N from Texas Instruments is an octal edge-triggered D-type latch with 3-state outputs, designed for bus interfacing and data latching in TTL-compatible systems. It operates at 4.5 V–5.5 V, features rising-edge clock triggering, shared output-enable (OE) control, and delivers ±128 mA output drive capability. It is used in I/O port expansion and memory address buffering where high-current bus driving and output isolation are required.

For engineers reviewing the SN74BCT374N datasheet, SN74BCT374N pinout, SN74BCT374N application, or SN74BCT374N equivalent, key selection considerations include its BiCMOS architecture for reduced ICCZ versus standard TTL, 70 MHz maximum clock frequency, 3-state output timing (tPZH/tPLZ ≤ 6.8 ns), and PDIP-20 package compatibility with legacy through-hole designs.

Technical Context

This device integrates eight independent D-type flip-flops sharing a single rising-edge-triggered CLK and active-low OE input. Its BiCMOS design combines bipolar output drivers for high current (±128 mA) with CMOS inputs for low static power and high noise immunity.

All eight channels latch data synchronously on CLK's positive transition; OE independently places outputs in high-impedance state without affecting internal storage. Input thresholds (VIH = 2 V, VIL = 0.8 V) and output voltage specs (VOH = 2.4 V @ –3 mA, VOL = 0.55 V @ 64 mA) ensure robust TTL-level interoperability.

Key Specifications

Pinout & Package

SN74BCT374N is housed in a 20-pin plastic dual in-line package (PDIP) with 25.40 mm × 6.35 mm body size, suitable for through-hole PCB assembly and prototyping.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74ACT374N and SN74LS374N, SN74BCT374N uniquely balances high-current 3-state drive (±128 mA), low ICCZ quiescent current, and 70 MHz operation - making it optimal for modernized 5 V bus systems requiring both legacy compatibility and improved thermal behavior.

Availability

SN74BCT374N is available at Aetrix Electronics and suitable for I/O port expansion, bus driving, and working register applications requiring stable component supply across industrial control, test equipment, and legacy system upgrades.

Supply support for SN74BCT374N 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 decades of experience in high-reliability logic families.

SN74BCT374N belongs to TI's BCT (Bipolar-CMOS-Transistor) logic series, engineered to replace TTL in high-drive, low-quiescent-current applications such as bus-oriented computing and industrial control systems.

FAQ

What is the maximum clock frequency supported by SN74BCT374N?

The SN74BCT374N supports a maximum clock frequency of 70 MHz under recommended operating conditions (VCC = 4.5 V to 5.5 V, TA = 0°C to 70°C, CL = 50 pF). This rating is validated across all eight channels and reflects guaranteed timing performance for synchronous data latching in high-speed bus interfaces. The SN74BCT374N achieves this using BiCMOS circuitry that minimizes propagation delay while maintaining robust noise margins.

Does SN74BCT374N require external pull-up or pull-down resistors on unused inputs?

Yes - all unused inputs of SN74BCT374N must be terminated to either VCC or GND to prevent floating states that cause excessive power consumption or oscillation. The device uses CMOS inputs with high impedance; leaving them unconnected violates the Recommended Operating Conditions. A 10-kΩ resistor is typically sufficient if direct connection isn't feasible, and this requirement applies to all D inputs, CLK, and OE pins not actively driven in the design.

Can SN74BCT374N outputs be safely tied together in wired-OR configuration?

No - SN74BCT374N features push-pull bipolar outputs that must never be directly connected together. Doing so risks destructive current flow during output state mismatches (e.g., one output high, another low). Wired-OR functionality requires open-collector or open-drain topology, which SN74BCT374N does not provide. Instead, use its 3-state outputs with shared bus control via OE to achieve time-multiplexed OR-like behavior safely.

What decoupling capacitance is recommended for SN74BCT374N?

A 0.1 µF ceramic capacitor placed as close as possible between VCC (pin 20) and GND (pin 10) is mandatory for stable SN74BCT374N operation. This value is specified in TI's Power Supply Recommendations to suppress high-frequency switching noise generated by its bipolar outputs. For noisy environments, paralleling with a 1 µF capacitor improves low-frequency filtering - but physical proximity to the IC pins remains critical to minimize inductance and maintain effective bypassing.

Is SN74BCT374N compatible with 3.3 V logic systems?

No - SN74BCT374N is strictly a 5 V device with a minimum supply voltage of 4.5 V and TTL-compatible input thresholds (VIH = 2 V min, VIL = 0.8 V max). It cannot reliably interface with 3.3 V logic without level translation, as its inputs may not recognize 3.3 V signals as valid HIGH, and its outputs exceed 3.3 V absolute maximum ratings when driven into 3.3 V systems. Use SN74LVC374A or similar 3.3 V–tolerant alternatives for mixed-voltage designs.