Texas Instruments CD4543BE

Overview

CD4543BE from Texas Instruments is a CMOS BCD-to-7-segment latch/decoder driver IC designed for direct LED display interfacing. It accepts 4-bit binary-coded decimal input, features phase and blanking control, operates over −55°C to +125°C, supports 3V–18V supply, and drives common-anode LED displays without external current-limiting resistors.

For engineers reviewing the CD4543BE datasheet, CD4543BE pinout, CD4543BE application, or CD4543BE equivalent, key selection considerations include its latch-enabled BCD decoding, active-low blanking, phase-selectable output polarity, wide V_DD range, and PDIP-16 package compatibility with legacy through-hole display subsystems.

Technical Context

The CD4543BE implements a synchronous latch followed by a BCD-to-7-segment decoder with active-high phase control (PH) that selects output polarity for common-anode vs. common-cathode drive - though internal design targets common-anode LEDs. Its LE (latch enable) input allows data capture on rising edge, while BI (blanking input) forces all segment outputs low when asserted.

It uses standard CMOS logic levels, exhibits high noise immunity, draws <100 µA quiescent current at 5V, and maintains valid segment outputs across its full 3V–18V operating voltage range without level-shifting circuitry.

Key Specifications

Pinout & Package

CD4543BE is supplied in a 16-lead plastic dual-in-line package (PDIP-N), 0.3-inch body width, with standard through-hole lead spacing (0.1 inch). Pin 1 is located at the left end of the top row, identified by a notch or dot marking.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar BCD-to-7-segment latch/decoder applications.

Compared with CD4511BE and 74HC4511, the CD4543BE uniquely combines latching, wide-temperature operation, resistorless common-anode drive, and programmable phase control - making it optimal for robust, low-complexity LED display subsystems where input timing is uncontrolled or thermal stress is present.

Availability

CD4543BE is available at Aetrix Electronics and suitable for industrial panel meters, digital thermometers, automotive dashboard displays, and test equipment counters requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for CD4543BE 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 company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.

The CD4543BE belongs to TI's legacy CD4000-series CMOS logic family, engineered for high-noise-immunity, wide-voltage-operation digital interfacing in resource-constrained and thermally demanding applications.

FAQ

What is the primary function of the CD4543BE?

The CD4543BE is a CMOS BCD-to-7-segment latch/decoder driver IC. Its primary function is to accept a 4-bit BCD input, latch it on the rising edge of LE, decode it into seven active-low segment outputs (a–g), and drive common-anode LED displays directly. The CD4543BE integrates blanking (BI) and phase (PH) controls to support flexible display configurations without external logic.

Does the CD4543BE require external current-limiting resistors for LED segments?

No, the CD4543BE does not require external current-limiting resistors when driving typical common-anode LED segments. Its outputs are designed to sink sufficient current (up to 10 mA per segment at V_DD = 15 V) while maintaining valid logic levels. However, maximum segment current depends on V_DD, ambient temperature, and duty cycle - consult the CD4543BE datasheet graphs for precise derating curves.

Can the CD4543BE drive common-cathode LED displays?

Yes, the CD4543BE can drive common-cathode displays using its PH (phase) input. When PH is held low, the segment outputs are inverted - producing active-high signals suitable for sourcing current into common-cathode LED anodes. This mode requires external current-limiting resistors and a pull-up supply, as the CD4543BE outputs cannot source significant current.

What is the purpose of the LE (Latch Enable) pin on the CD4543BE?

LE is a positive-edge-triggered latch control input. When LE transitions from low to high, the CD4543BE captures and holds the current 4-bit BCD input (A–D) in its internal latch. While LE remains low, the displayed digits remain stable even if input bits change - preventing display glitches during asynchronous updates. This behavior makes the CD4543BE ideal for microcontroller-driven displays where BCD data may be updated mid-display cycle.

Is the CD4543BE RoHS compliant and what is its moisture sensitivity level?

Yes, the CD4543BE is RoHS compliant (lead finish: NIPDAU). As a PDIP-16 package, it carries no moisture sensitivity level (MSL) rating - "N/A for Pkg Type" per TI's packaging documentation. Unlike surface-mount variants, the plastic DIP package is not moisture-sensitive and does not require dry-pack or bake-out prior to soldering.