Texas Instruments CD4555BEG4

Overview

CD4555BEG4 from Texas Instruments is a dual 1-of-4 decoder/demultiplexer IC in a 16-pin PDIP package, operating across –55°C to +125°C, with supply voltage range 3 V to 18 V, and TTL/CMOS-compatible inputs. It enables address decoding in microcontroller peripheral interfaces and channel selection in analog multiplexing systems.

For engineers reviewing the CD4555BEG4 datasheet, CD4555BEG4 pinout, CD4555BEG4 application, or CD4555BEG4 equivalent, this page delivers verified functional identity, validated pin assignments, confirmed temperature and voltage specs, and real-world use context for industrial control and legacy system design.

Technical Context

The CD4555BEG4 implements two independent 1-of-4 decoders, each accepting two binary inputs (A0/A1) and enabling active-low outputs (Y0–Y3) under control of an active-low enable (E). Each decoder operates with full CMOS logic levels and exhibits high noise immunity due to its symmetrical input threshold.

It features complementary output structure per decoder section - all four outputs are active-low and mutually exclusive when enabled - and supports cascading via enable propagation between sections. No internal latching or clocking is present; operation is purely combinational.

Key Specifications

Pinout & Package

CD4555BEG4 is housed in a 16-pin plastic dual-in-line package (PDIP-N), 7.62 mm pitch, 19.18 mm length, with standard through-hole mounting and RoHS-compliant NiPdAu lead finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CD4555BEG4, CD4555BM96 offers SMT compatibility without electrical trade-offs, while CD4555BPWRG4 adds mechanical miniaturization - both retain identical decode logic, timing, and temperature performance, making them functionally interchangeable where package constraints allow.

Availability

CD4555BEG4 is available at Aetrix Electronics and suitable for industrial control systems, legacy embedded instrumentation, and aerospace avionics requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for CD4555BEG4 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 founded in 1930, specializing in analog, embedded processing, and logic solutions with broad industrial and automotive qualification.

The CD4555BEG4 belongs to TI's CD4000B-series CMOS logic family, designed for robust, low-power, wide-voltage-operation digital interfacing in harsh environments and long-lifecycle systems.

FAQ

What is the logic function of the CD4555BEG4?

The CD4555BEG4 integrates two independent 1-of-4 decoders. Each accepts two binary inputs (A0/A1 or A2/A3) and an active-low enable (E1/E2), producing four active-low outputs (Y0–Y3) where exactly one output goes low per valid input code when enabled. It performs pure combinational decoding with no internal storage or clocking - the CD4555BEG4 output states change synchronously with input transitions.

Does the CD4555BEG4 support 3.3 V logic systems?

Yes, the CD4555BEG4 operates reliably down to 3 V supply voltage, and its CMOS inputs recognize 3.3 V logic HIGH (≥70% VDD) and LOW (≤30% VDD) thresholds. When powered at 3.3 V, the CD4555BEG4 maintains full functionality and meets specified propagation delay and noise margin specs - no level shifters are required for interfacing with 3.3 V microcontrollers.

Can the CD4555BEG4 outputs drive LEDs directly?

Yes, each CD4555BEG4 output can sink up to 4.2 mA at VDD = 5 V and 1.5 mA at VDD = 3 V (per TI datasheet conditions), sufficient to illuminate standard indicator LEDs with appropriate current-limiting resistors. The CD4555BEG4 outputs are active-low and open-drain compatible, allowing direct connection to LED anodes tied to VDD - no external transistor is needed for basic status indication.

Is the CD4555BEG4 pin-compatible with the CD4556B?

No, the CD4555BEG4 and CD4556B are not pin-compatible. While both are 16-pin CMOS decoders, the CD4556B is a dual 2-line-to-4-line decoder with inverted outputs (active-high), whereas the CD4555BEG4 has active-low outputs and different pin assignments for enables and outputs. Swapping them requires PCB redesign - the CD4555BEG4 cannot serve as a drop-in replacement for CD4556B.

What is the maximum operating frequency for address decoding with the CD4555BEG4?

The CD4555BEG4 does not have a clock input and is not rated for a maximum operating frequency. Its usable speed is determined by propagation delay: typ. 40 ns at VDD = 10 V, 60 ns at VDD = 5 V. For reliable decoding in synchronous systems, the CD4555BEG4 supports address valid windows ≥80 ns - enabling use with 80C51 derivatives running at ≤12 MHz and FPGA-based controllers with ≥10 ns setup/hold margins.