Texas Instruments CD4555BF3A

Overview

CD4555BF3A from Texas Instruments is a dual 1-of-4 decoder/demultiplexer in a 16-lead ceramic dual-in-line package (CDIP), operating across –55°C to +125°C, with TTL-compatible inputs, CMOS-level outputs, and propagation delay of 120 ns typical at 5 V. It enables address decoding in military-grade embedded control systems and analog multiplexing in precision sensor interface circuits.

For engineers reviewing the CD4555BF3A datasheet, CD4555BF3A pinout, CD4555BF3A application, or CD4555BF3A equivalent, key selection factors include its hermetic F3A packaging for high-reliability environments, dual independent decode logic blocks, and compatibility with both 5-V and 15-V supply rails in legacy industrial instrumentation.

Technical Context

The CD4555BF3A implements two independent 1-of-4 decoders, each with active-low enable (E̅) and active-high outputs. Each decoder accepts two binary inputs (A, B) and drives four mutually exclusive low-asserted outputs (Y0–Y3), supporting address selection and signal routing without external gating logic.

It uses standard CMOS silicon-on-sapphire process technology, delivering rail-to-rail output swing, input hysteresis for noise immunity, and static discharge protection per MIL-STD-883. Its logic thresholds are referenced to V_DD/2, enabling robust operation across wide voltage and temperature ranges.

Key Specifications

Pinout & Package

CD4555BF3A is housed in a 16-pin ceramic dual-in-line package (CDIP, drawing J), 0.300-inch body width, with 0.100-inch lead pitch and glass-sealed leads. The package meets MIL-STD-883 requirements for mechanical shock, thermal cycling, and hermeticity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual 1-of-4 decoder applications.

Compared with CD4555BE and CD4555BM, the CD4555BF3A uniquely provides hermetic sealing and MIL-qualified screening-making it irreplaceable in mission-critical systems where environmental integrity outweighs cost or footprint constraints.

Availability

CD4555BF3A is available at Aetrix Electronics and suitable for avionics subsystems, industrial PLCs, automated test equipment, and military radio platforms requiring stable component supply under extended temperature and reliability specifications.

Supply support for CD4555BF3A 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 high-reliability logic solutions, with over 50 years of heritage in aerospace and defense component development.

The CD4555BF3A belongs to TI's CD4000B series of radiation-tolerant, high-voltage CMOS logic devices, designed specifically for legacy system upgrades and new deployments in harsh-environment electronics.

FAQ

What is the maximum clock rate supported by CD4555BF3A for reliable decoding?

The CD4555BF3A is not a clocked device-it operates asynchronously. Its maximum reliable input transition rate is determined by propagation delay: at V_DD = 10 V, t_PD = 70 ns typical, supporting input address changes up to ~7 MHz in worst-case combinatorial paths. For guaranteed timing in synchronous systems, designers must observe setup/hold margins relative to controlling clocks. The CD4555BF3A itself imposes no internal clock limit.

Does CD4555BF3A support 3.3-V logic interfacing?

No-CD4555BF3A has minimum V_DD = 3 V, but its input threshold is V_DD/2, making 3.3-V CMOS outputs marginally compatible only if V_DD ≥ 4.5 V. At 3.3-V supply, input logic '1' requires ≥1.65 V, which may not be met by 3.3-V CMOS drivers under load. For true 3.3-V systems, TI recommends CD74HC139 or SN74LV139 instead of CD4555BF3A.

Is CD4555BF3A pin-compatible with CD4556BF3A?

No-CD4555BF3A and CD4556BF3A share the same 16-pin CDIP package and pin count, but differ functionally: CD4555BF3A is dual 1-of-4 decoder with active-low outputs, while CD4556BF3A is dual 1-of-4 decoder with active-high outputs. Their output polarities are inverted; direct substitution will cause logic inversion unless external inverters are added. Pinout assignment is identical, but functional replacement requires circuit-level validation.

What is the meaning of the 'F3A' suffix in CD4555BF3A?

The 'F3A' suffix designates a 16-lead hermetic ceramic dual-in-line package conforming to MIL-STD-1835 outline J, with glass-sealed leads, gold-plated terminations, and screening per MIL-PRF-38535 Class B. This suffix identifies the part as a high-reliability, military-qualified variant-not merely a packaging option-but a fully tested and certified version for defense and aerospace use.

Can CD4555BF3A drive LED indicators directly?

Yes-CD4555BF3A outputs can sink up to 4.2 mA at V_DD = 10 V with V_OL ≤ 0.5 V, sufficient to drive low-current LEDs (e.g., 2-mA red LEDs) with appropriate current-limiting resistors. However, due to its active-low outputs, LEDs must be anode-connected to V_DD and cathode to Yx pins. For higher-current or AC-coupled indicators, external transistor buffering is recommended. CD4555BF3A does not source current.