Texas Instruments SN7400DG4

Overview

SN7400DG4 from Texas Instruments is a quadruple 2-input positive-NAND gate IC in SOIC-14 package, operating at 4.75–5.25 V supply, with TTL-compatible inputs (VIH = 2 V, VIL = 0.8 V), 22 ns max propagation delay (tPLH/tPHL), and rated for 0°C to 70°C industrial temperature range. It performs Y = A·B logic in positive logic and is used in digital control logic, error detection circuits, and consumer audio system glue logic.

For engineers reviewing the SN7400DG4 datasheet, SN7400DG4 pinout, SN7400DG4 application, or SN7400DG4 equivalent, key selection considerations include its 14-pin SOIC footprint, TTL-level input compatibility, unbalanced output drive (IOL = 16 mA / IOH = –0.4 mA), and absence of internal ESD protection beyond standard HBM ratings.

Technical Context

The SN7400DG4 implements four independent NAND gates using bipolar transistor-transistor logic (TTL) architecture, with open-collector–compatible totem-pole outputs and no internal pull-ups. Its input stage features multiple-emitter transistors that break down above 5.5 V, requiring external series resistors on unused or overvoltage-prone inputs.

It operates strictly within 4.75–5.25 V VCC and is not compatible with 3.3-V logic families without level translation; while inputs accept 3.3-V signals per datasheet note, output swing remains 0.4 V/3.4 V under load, limiting direct interfacing with modern low-voltage systems.

Key Specifications

Pinout & Package

SN7400DG4 uses a 14-pin SOIC (Small Outline Integrated Circuit) package with 8.65 mm × 3.91 mm body size and standard 1.27 mm pitch. Pin 1 is marked by a beveled corner or dot; pin numbering follows counterclockwise convention from top-left when viewed from top with marking side up.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NAND gate applications.

Compared with SN7400DG4, SN74LS00D trades speed for power efficiency in legacy 5-V systems, while SN74HC00DR offers voltage flexibility and speed at the cost of TTL input compatibility - making it unsuitable as a drop-in replacement without circuit review.

Availability

SN7400DG4 is available at Aetrix Electronics and suitable for AV receivers, portable audio docks, and Blu-ray players requiring stable component supply across long-lifecycle consumer electronics programs.

Supply support for SN7400DG4 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 U.S.-based semiconductor company founded in 1930, specializing in analog, embedded processing, and logic solutions for industrial, automotive, and consumer markets.

The SN7400DG4 belongs to TI's classic 7400-series TTL logic family, designed for robust, low-cost digital glue logic in 5-V systems where predictable timing and interoperability with legacy components are essential.

FAQ

What is the maximum supply voltage for SN7400DG4?

The absolute maximum VCC for SN7400DG4 is 7 V, but recommended operating range is strictly 4.75 V to 5.25 V. Exceeding 5.25 V may cause excessive current draw and thermal runaway, while operation below 4.75 V risks marginal logic levels and increased propagation delay. Always use regulated 5-V supplies with ±2.5% tolerance for reliable SN7400DG4 performance.

Can SN7400DG4 interface directly with 3.3-V microcontrollers?

SN7400DG4 inputs accept 3.3-V logic-high signals (VIH min = 2.0 V), so 3.3-V outputs can drive SN7400DG4 safely. However, SN7400DG4 outputs swing to ~3.4 V (VOH) and ~0.4 V (VOL) - insufficient for reliable 3.3-V input recognition without external pull-up or level translation. For bidirectional interfacing, SN7400DG4 is not a direct solution; consider SN74LVC00 instead.

Does SN7400DG4 have built-in ESD protection?

SN7400DG4 has limited inherent ESD protection - datasheet specifies ±500 V HBM rating but does not guarantee CDM or MM robustness. It lacks integrated clamp diodes or current-limiting structures found in modern logic families. Always handle SN7400DG4 with grounded wrist straps, store in conductive foam, and avoid contact with pins before soldering to prevent latent damage.

What is the purpose of NC pins on SN7400DG4?

SN7400DG4 has no NC (no-connect) pins in its SOIC-14 package. All 14 pins are functionally assigned: pins 1–2, 4–6, 8–14 carry gate inputs/outputs, VCC, or GND. The "NC" labels in generic family diagrams refer to variants like SN74xx00 PS (18-pin SO) or LCCC (20-pin), not the SN7400DG4 D-package. Misidentifying pins as NC could lead to incorrect PCB layout or floating node issues.

How should unused inputs on SN7400DG4 be terminated?

Unused inputs on SN7400DG4 must never float - they should be tied to VCC (for logic HIGH) or GND (for logic LOW) via direct connection or 1–10 kΩ resistor. Leaving inputs unconnected causes erratic output behavior, increased supply current, and potential oscillation due to TTL input stage sensitivity. For unused gates, tie both inputs to VCC to force output LOW and minimize dynamic power.