Texas Instruments CD74ACT02EG4

Overview

CD74ACT02EG4 from Texas Instruments is a quadruple 2-input positive-NOR gate logic IC in PDIP-14 package, operating at 4.5–5.5 V supply, with ±24-mA output drive, 3.1–12.2 ns propagation delay (tPLH/tPHL), and TTL-voltage-compatible inputs. It performs Y = A + B Boolean function in digital control, address decoding, and bus arbitration circuits.

For engineers reviewing the CD74ACT02EG4 datasheet, CD74ACT02EG4 pinout, CD74ACT02EG4 application, or CD74ACT02EG4 equivalent, key selection criteria include its balanced propagation delays, SCR-latchup-resistant CMOS process, 2-kV ESD rating per MIL-STD-883, fanout to 15 F-series devices, and compatibility with legacy TTL logic levels.

Technical Context

The CD74ACT02EG4 implements four independent NOR gates using advanced ACT (Advanced CMOS Technology) silicon, combining bipolar-speed performance with CMOS power efficiency. Its input structure accepts TTL-level signals (VIH ≥ 2 V, VIL ≤ 0.8 V) while driving standard CMOS loads.

Each gate exhibits matched tPLH and tPHL delays, enabling predictable timing in synchronous logic trees. The device operates across –40°C to 85°C (commercial) and –55°C to 125°C (extended/military-grade variants), with absolute max ratings including 6-V supply and ±50-mA output clamp current.

Key Specifications

Pinout & Package

Packaged in 14-pin plastic dual in-line package (PDIP-N), CD74ACT02EG4 features through-hole mounting, 0.3-inch body width, and JEDEC-standard pin spacing (0.1 inch). Thermal impedance θJA = 80°C/W supports moderate-power logic applications without forced cooling.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CD74ACT02EG4, SN74ACT02N offers identical performance and drop-in compatibility with enhanced lifecycle assurance, while 74VHC02N trades drive strength and ESD protection for broader voltage operation and lower static power - making it suitable only in non-TTL, noise-controlled contexts.

Availability

CD74ACT02EG4 is available at Aetrix Electronics and suitable for industrial control logic, legacy system interface, power sequencing arbiter, and digital bus isolation applications requiring stable component supply and long-term obsolescence management.

Supply support for CD74ACT02EG4 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 heritage in military-qualified and industrial-grade logic families.

The CD74ACT02EG4 belongs to TI's Advanced CMOS Technology (ACT) logic series, engineered to deliver bipolar-speed performance (comparable to 74F) with CMOS power efficiency and robustness for mission-critical industrial and aerospace systems.

FAQ

What logic family does CD74ACT02EG4 belong to, and how does it differ from standard 74HC or 74LS devices?

CD74ACT02EG4 belongs to Texas Instruments' Advanced CMOS Technology (ACT) family. Unlike 74HC, it offers TTL-compatible inputs (VIH ≥ 2 V) and higher output drive (±24 mA vs. ±4 mA for HC), matching 74F speed while consuming far less power. Versus 74LS, CD74ACT02EG4 provides CMOS-level ICC (µA vs. mA), superior noise margins, and no input current loading - making it ideal for upgrading LS-based systems without redesigning bias networks or pull-ups.

Is CD74ACT02EG4 pin-compatible with the older CD74ACT02E or SN74ACT02N?

Yes, CD74ACT02EG4 is fully pin-compatible with CD74ACT02E and SN74ACT02N - all share identical 14-pin PDIP (N) package, pinout, and logic function. The "G4" suffix denotes TI's RoHS-compliant green packaging (lead-free, halogen-free), with no electrical or timing differences. Engineers may substitute CD74ACT02EG4 directly onto existing CD74ACT02E footprints without layout changes.

What is the maximum fanout capability of CD74ACT02EG4 when driving 74F-series logic?

CD74ACT02EG4 supports fanout to 15 F-series devices per output, as specified in its datasheet. This is enabled by its ±24-mA output drive strength and low output impedance, which maintain valid VOH/VOL levels even under heavy capacitive and current loading. For reliable operation, ensure proper VCC decoupling and avoid exceeding total output capacitance limits (CL ≤ 50 pF for published timing specs).

Does CD74ACT02EG4 require external pull-up or pull-down resistors on unused inputs?

Yes - all unused inputs of CD74ACT02EG4 must be tied to either VCC or GND. Floating CMOS inputs cause increased ICC, potential oscillation, and susceptibility to noise-induced switching. TI's application report SCBA004 explicitly warns that unconnected inputs can raise quiescent current by orders of magnitude and degrade noise immunity. Never leave any of the eight inputs (Pins 1,2,4,5,8,9,12,13) open in a working CD74ACT02EG4 design.

Can CD74ACT02EG4 operate reliably at 3.3 V supply voltage?

No - CD74ACT02EG4 is specified only for 4.5 V to 5.5 V operation per its recommended conditions. At 3.3 V, VIH and VIL thresholds become undefined, output drive collapses, and propagation delays increase unpredictably. For 3.3-V systems, TI recommends 74LVC02 or SN74AUP1G02; CD74ACT02EG4 must be used strictly within its 5-V domain to guarantee timing, drive, and logic-level compliance.