Texas Instruments CD4543BNS

Overview

CD4543BNS from Texas Instruments is a CMOS BCD-to-7-segment latch/decoder/driver IC designed for direct LED display interfacing. It features active-high latching, phase-controlled blanking, and ripple-blank input for cascaded multi-digit displays. Operates from 3 V to 18 V supply, supports common-anode LED outputs, and delivers up to 10 mA sink per segment at V_DD = 15 V.

For engineers reviewing the CD4543BNS datasheet, CD4543BNS pinout, CD4543BNS application, or CD4543BNS equivalent, key selection considerations include its common-anode output architecture, latch-enable timing behavior, ripple-blank propagation delay, and compatibility with legacy 4000-series logic voltage ranges.

Technical Context

The CD4543BNS implements a synchronous BCD-to-7-segment decoding function with integrated D-type latch and active-low phase control (PH) for multiplexed display timing. Its ripple-blank input (RBI) enables zero-suppression across multiple digits via daisy-chained blanking signals.

Latch operation occurs on the rising edge of LE (Latch Enable), isolating the internal decoder from input changes until next latch event. Output drivers are open-drain compatible only in common-anode configuration - no internal pull-ups - requiring external current-limiting resistors per segment.

Key Specifications

Pinout & Package

CD4543BNS is supplied in a 16-lead SOIC package (Package Drawing NS), 3.9 mm body width, 1.75 mm height, with 0.65 mm lead pitch and gull-wing terminations.

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 MC14495P, the CD4543BNS uniquely combines latching, phase control, and ripple-blank signaling in a single 16-pin SOIC package - enabling compact, low-firmware LED interfaces for industrial and instrumentation systems operating across 3–18 V.

Availability

CD4543BNS is available at Aetrix Electronics and suitable for digital panel meters, industrial process controllers, legacy instrumentation upgrades, and energy meter display interfaces requiring stable component supply and long-term industrial temperature support.

Supply support for CD4543BNS 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 U.S.-based semiconductor company founded in 1930, specializing in analog, embedded processing, and logic ICs for industrial, automotive, and consumer markets.

The CD4543BNS belongs to TI's CD4000B series of buffered CMOS logic devices, engineered for robust operation in noisy industrial environments with wide supply tolerance and high noise immunity.

FAQ

What is the maximum supply voltage rating for the CD4543BNS?

The CD4543BNS is rated for operation up to 18 V DC on V_DD, with guaranteed performance across the full -55 °C to +125 °C temperature range. Exceeding 18 V risks permanent damage to internal oxide layers. For reliable long-term use in industrial applications, TI recommends maintaining V_DD ≤ 16.5 V with ≥100 nF ceramic decoupling placed within 5 mm of the CD4543BNS V_DD/V_SS pins.

Can the CD4543BNS drive common-cathode LED displays?

No, the CD4543BNS is designed exclusively for common-anode LED displays. Its segment outputs (pins 9–15) are open-drain N-channel drivers that sink current to ground. Driving a common-cathode display would require external PNP transistors or a level-shifting buffer - defeating the purpose of its integrated driver architecture. Use CD4511BE instead for common-cathode applications.

How does the ripple-blank function work across multiple CD4543BNS devices?

In a cascaded configuration, the RO (Ripple-Blank Output) pin of a more-significant digit drives the RBI (Ripple-Blank Input) of the next less-significant digit. When RBI is low and all BCD inputs are zero, that digit blanks and asserts RO low - propagating suppression leftward. The CD4543BNS RO pin is active-low and open-drain, requiring a pull-up resistor (typically 10 kΩ to V_DD) for proper logic level restoration between digits.

Is the CD4543BNS pin-compatible with older CD4543 variants?

Yes, the CD4543BNS maintains identical pinout, logic function, and electrical specifications with earlier CD4543B versions including CD4543BE (PDIP) and CD4543BM (SOIC). All share the same 16-pin SOIC (NS) footprint, signal assignments, and timing parameters - enabling direct replacement in existing PCB layouts without modification.

What is the purpose of the Phase Control (PH) pin on the CD4543BNS?

The PH pin on the CD4543BNS is an active-low control that enables or disables segment outputs independently of latch state. When PH is high, outputs remain in their last latched state; when PH is low, outputs reflect real-time BCD inputs. This allows precise timing of LED turn-on/off during multiplexed display scanning - critical for eliminating ghosting and ensuring uniform brightness across digits.