Texas Instruments CD4543BPW

Overview

CD4543BPW from Texas Instruments is a CMOS BCD-to-7-segment latch/decoder/driver IC designed for direct LED display interfacing. It accepts 4-bit BCD input, features phase and blanking control, operates over −55°C to +125°C, supports 3V–18V supply, and drives common-anode LED segments with active-low outputs.

For engineers reviewing the CD4543BPW datasheet, CD4543BPW pinout, CD4543BPW application, or CD4543BPW equivalent, this device is selected for high-voltage LED digit driving in industrial panel meters, legacy instrumentation displays, and low-power multiplexed 7-segment systems where TTL/CMOS compatibility and latch functionality are required.

Technical Context

The CD4543BPW implements a synchronous latch followed by a BCD-to-7-segment decoder with active-low open-drain outputs optimized for common-anode LEDs. Its PH (phase) input enables polarity selection for AC-coupled displays, while the BL (blank) input forces all segment outputs high to disable display output.

It uses standard CMOS logic architecture with buffered inputs, rail-to-rail output swing, and inherent noise immunity. The device does not include internal current-limiting resistors-external series resistors are required per segment to set LED current within safe operating limits.

Key Specifications

Pinout & Package

TSSOP-16 (PW) package: 4.4 mm × 5.0 mm body, 0.65 mm pitch, 1.2 mm max height, exposed pad not electrically connected, JEDEC MO-153 compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CD4543BM96 and MC14495P, the CD4543BPW offers the smallest footprint (TSSOP-16), active production status with tape-and-reel packaging, and unique PH-controlled polarity inversion-making it optimal for new designs requiring compact size, long-term supply, and AC LED drive capability.

Availability

CD4543BPW is available at Aetrix Electronics and suitable for industrial panel meters, legacy test equipment displays, and multiplexed instrument clusters requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for CD4543BPW 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 logic ICs, with decades of heritage in CMOS logic families including the CD4000B series.

The CD4543B product line was engineered for robust, high-voltage digital display interfacing in industrial, aerospace, and instrumentation systems where reliability across extreme temperatures and supply voltages is critical.

FAQ

What is the maximum segment output current rating for CD4543BPW?

The CD4543BPW is rated for continuous DC output current of 10 mA per segment at V_DD = 15 V and T_A = 25°C. Absolute maximum ratings specify 25 mA peak per output, but sustained operation above 10 mA requires thermal derating and proper PCB copper area. The CD4543BPW does not include internal current limiting, so external series resistors must be sized accordingly.

Does CD4543BPW support blanking during BCD input transitions?

Yes, the CD4543BPW uses an asynchronous active-high BL (blank) input that forces all seven segment outputs high (non-driving state) regardless of latch state, BCD input, or PH setting. This allows clean blanking during digit updates or auto-ranging events without affecting the internal latch register. The CD4543BPW maintains its last latched BCD value during blanking and resumes display immediately when BL returns low.

Can CD4543BPW drive common-cathode LED displays?

No, the CD4543BPW has active-low open-drain outputs designed exclusively for common-anode LED configurations. Driving common-cathode displays would require external P-channel MOSFETs or logic inverters per segment, which defeats the purpose of integrated decoding. For common-cathode applications, alternatives like the 74LS47 or MC14495 (with appropriate external logic) are more suitable than the CD4543BPW.

Is CD4543BPW pin-compatible with CD4543BPWR?

Yes, CD4543BPW and CD4543BPWR share identical TSSOP-16 (PW) package dimensions, pinout, and electrical specifications. The "R" suffix denotes tape-and-reel packaging (2000 pcs/reel), while CD4543BPW refers to the same die and package in non-reel form (obsolete status per TI). Both part numbers map to the same silicon and pin functions - the CD4543BPW is functionally and physically identical to CD4543BPWR except for packaging format and availability status.

What is the purpose of the PH pin on CD4543BPW?

The PH (phase) pin on CD4543BPW selects output polarity: when PH = high, segment outputs are active-low (standard common-anode drive); when PH = low, outputs invert to active-high, enabling AC-coupled LED operation. This eliminates the need for external H-bridge circuitry in applications where LED electrode longevity is critical, such as automotive instrument clusters running continuously. The CD4543BPW's PH function is unique among BCD decoders in the CD4000B family.