Texas Instruments SN74LS02DE4

Overview

SN74LS02DE4 from Texas Instruments is a quad 2-input NOR gate logic IC in SOIC-14 package, operating over 0°C to 70°C, with typical propagation delay of 15 ns at VCC = 5 V and fan-out of 20 TTL loads. It implements positive-logic NOR function in standard LS-TTL family for digital control and signal conditioning in industrial logic systems.

For engineers reviewing the SN74LS02DE4 datasheet, SN74LS02DE4 pinout, SN74LS02DE4 application, or SN74LS02DE4 equivalent, this page delivers verified electrical specs, package dimensions, functional role in combinational logic design, and validated drop-in alternatives for legacy TTL system upgrades and repair.

Technical Context

The SN74LS02DE4 implements four independent 2-input NOR gates using bipolar transistor-transistor logic (TTL) with Schottky-clamped outputs. Each gate features complementary emitter-follower output stage for improved switching speed and noise immunity.

It operates strictly at VCC = 5 V ±5%, draws 19 mA maximum ICC per package under worst-case loading, and maintains guaranteed VOH ≥2.7 V and VOL ≤0.5 V across full temperature range - meeting LS-TTL voltage thresholds for interoperability with 74LS, 74L, and compatible families.

Key Specifications

Pinout & Package

SOIC-14 (D) package: 3.9 mm body width, 1.27 mm lead pitch, gull-wing leads, RoHS-compliant NiPdAu finish, MSL Level-1 (unlimited floor life).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NOR gate applications.

Compared with SN74LS02DR and SN74LS02N, the SN74LS02DE4 offers identical electrical performance in a RoHS-compliant SOIC-14 tube package - making it ideal for small-batch manufacturing, field repair, and inventory consolidation where tape-and-reel volume or through-hole mounting are not required.

Availability

SN74LS02DE4 is available at Aetrix Electronics and suitable for industrial control logic, digital instrumentation, legacy system repair, and educational prototyping requiring stable component supply and long-term obsolescence mitigation.

Supply support for SN74LS02DE4 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 SN74LS02DE4 belongs to TI's legacy 74LS logic family, designed specifically for reliable, low-power, pin-compatible upgrades of original 74-series TTL circuits in cost-sensitive and long-lifecycle applications.

FAQ

What is the maximum operating frequency supported by SN74LS02DE4?

The SN74LS02DE4 is not characterized for maximum clock frequency, as it is a combinational logic device. Its 15 ns typical propagation delay supports reliable operation in asynchronous logic paths up to approximately 30 MHz toggle rate. For synchronous systems, timing analysis must account for setup/hold margins of downstream registers; the SN74LS02DE4 itself imposes no inherent clock limit but must meet path delay constraints defined by the full logic chain.

Can SN74LS02DE4 be used with 3.3 V logic systems?

No, SN74LS02DE4 is strictly a 5 V-only device. Its input thresholds (VIH ≥2.0 V, VIL ≤0.8 V) and output voltage levels (VOH ≥2.7 V, VOL ≤0.5 V) are specified only at VCC = 5 V ±5%. Interfacing with 3.3 V systems requires level-shifting circuitry; direct connection risks undefined logic states and potential damage due to overvoltage on inputs or excessive current draw.

Is SN74LS02DE4 pin-compatible with older 7402 or 74S02 devices?

Yes, SN74LS02DE4 is fully pin-compatible with 7402 (standard TTL), 74S02 (Schottky TTL), and all 74LS02 variants. It uses the standard 14-pin SOIC-D footprint with identical pin assignments: VCC (14), GND (7), and four NOR gate input/output pairs occupying pins 1–6, 8–13. No PCB modification is needed when replacing these predecessors.

What is the recommended decoupling for SN74LS02DE4?

TI specifies a minimum 0.1 µF ceramic capacitor placed between VCC (pin 14) and GND (pin 7), with lead length ≤5 mm. For boards with multiple SN74LS02DE4 devices or high-speed switching, add a bulk 4.7 µF–10 µF tantalum or aluminum electrolytic capacitor per power rail segment. This prevents VCC droop and ground bounce that could cause metastability or false triggering in adjacent logic.

Does SN74LS02DE4 support hot-swap or live-insertion?

No, SN74LS02DE4 is not designed for hot-swap operation. Its bipolar TTL inputs lack protection against supply sequencing violations or floating inputs during insertion. Applying VCC before GND, or connecting inputs while power is off, may cause latch-up or parametric shift. Always power-cycle the board before inserting or removing SN74LS02DE4.