Texas Instruments CD54ACT623F3A

Overview

CD54ACT623F3A from Texas Instruments is a military-grade octal bus transceiver with 3-state outputs, featuring ACT logic family characteristics (TTL-compatible inputs, CMOS outputs), 20-pin CDIP package, -55°C to +125°C operating temperature range, and 7.5 ns typical propagation delay at VCC = 5 V. It serves in high-reliability data bus isolation and bidirectional level translation in avionics and defense subsystems.

For engineers reviewing the CD54ACT623F3A datasheet, CD54ACT623F3A pinout, CD54ACT623F3A application, or CD54ACT623F3A equivalent, key selection considerations include military QML qualification, dual-supply tolerance (4.5–5.5 V), symmetric output drive (±24 mA), input hysteresis for noise immunity, and compatibility with legacy TTL/CMOS systems requiring robust bus arbitration.

Technical Context

The CD54ACT623F3A implements an octal bidirectional transceiver with independent output-enable (OE) and direction-control (DIR) inputs per channel group. Its ACT-series architecture delivers rail-to-rail CMOS output swing while accepting standard TTL-level inputs (VIL ≤ 0.8 V, VIH ≥ 2.0 V).

It operates strictly from a single 5-V supply (4.5–5.5 V), supports hot-insertion via Ioff protection, and features bus-hold circuitry on all inputs to prevent floating states when un-driven - critical for deterministic operation in ruggedized backplane environments.

Key Specifications

Pinout & Package

CD54ACT623F3A is housed in a 20-lead Ceramic Dual-In-Line Package (CDIP), hermetically sealed, with 0.3-inch body width and 0.1-inch lead pitch. Pin 1 marked by notch or dot; leads are tin-lead (Pb/Sn) finished per legacy military specification.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal bus transceiver applications.

Compared with CD74ACT623M96 and SN74ACT623N, the CD54ACT623F3A uniquely provides QML-38535 Class B qualification, -55°C to +125°C operation, integrated bus-hold, and Ioff - making it the sole choice for deployed defense electronics requiring guaranteed lifetime reliability under extreme conditions.

Availability

CD54ACT623F3A is available at Aetrix Electronics and suitable for avionics data bus interface, ground vehicle mission computing, tactical radio baseband processing, and military radar signal conditioning requiring stable component supply across long production lifecycles.

Supply support for CD54ACT623F3A 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 connectivity solutions with deep expertise in high-reliability design and military qualification.

The CD54ACT623F3A belongs to TI's military logic product line, engineered specifically for deterministic, fault-tolerant data routing in defense, aerospace, and critical infrastructure systems where failure is not an option.

FAQ

What is the qualification status of CD54ACT623F3A for military applications?

The CD54ACT623F3A is fully qualified per MIL-PRF-38535 Class B and listed as a QML-certified device for military and defense applications. It undergoes rigorous screening including temperature cycling, burn-in, and lot traceability - confirming its suitability for deployment in avionics, radar, and secure communications platforms where reliability is non-negotiable. This qualification is documented in TI's official packaging addendum and military data sheet SCHS286A.

Does CD54ACT623F3A support hot-swap or partial power-down operation?

Yes, CD54ACT623F3A incorporates Ioff protection, which disables output drivers when VCC = 0 V, preventing current backflow into powered sections of the bus. This feature enables safe insertion/removal in live systems and supports partial power-down modes in multi-rail architectures - essential for mission-critical platforms requiring graceful degradation during power faults.

What is the maximum clock frequency supported by CD54ACT623F3A in bus-transceiver mode?

The CD54ACT623F3A does not operate synchronously with a clock; it is an asynchronous transceiver. However, its 7.5 ns typical propagation delay supports reliable data transfer at effective bus rates up to 100 MHz (10 ns period), assuming proper PCB layout, load capacitance ≤50 pF, and clean power delivery - verified across its full -55°C to +125°C operating range.

Can CD54ACT623F3A replace CD74AC623E in existing designs?

No - CD54ACT623F3A uses ACT logic (TTL-compatible inputs, CMOS outputs), while CD74AC623E uses AC logic (CMOS inputs). Their input threshold specifications differ significantly: CD54ACT623F3A accepts VIL ≤ 0.8 V and VIH ≥ 2.0 V, whereas CD74AC623E requires VIL ≤ 1.5 V and VIH ≥ 3.5 V. Substituting without redesign risks logic misreads, especially at temperature extremes or with marginal drive strength.

Is bus-hold functionality enabled by default on CD54ACT623F3A inputs?

Yes, bus-hold circuitry is internal and always active on all inputs of CD54ACT623F3A - no external components or configuration required. Each input includes a feedback resistor network (~100 kΩ) that latches the last valid logic state when the driving source is removed or goes high-impedance, eliminating floating nodes and reducing susceptibility to EMI in unbuffered bus environments.