Texas Instruments CD4511BF3A

Overview

CD4511BF3A from Texas Instruments is a BCD-to-7-segment latch/decoder/driver IC designed for direct LED display control in digital instrumentation and panel meters. It features active-low Lamp Test (LT), Blanking (BL), and Latch Enable (LE) inputs, operates over –55°C to +125°C, supports 3V–18V V_DD, and drives common-cathode 7-segment displays with segment current up to 25 mA per output.

For engineers reviewing the CD4511BF3A datasheet, CD4511BF3A pinout, CD4511BF3A application, or CD4511BF3A equivalent, key selection criteria include its TTL/CMOS-compatible BCD input interface, integrated latching function, high-voltage open-drain segment outputs, and hermetic ceramic DIP-16 packaging suitable for military-grade and high-reliability industrial environments.

Technical Context

The CD4511BF3A implements a synchronous BCD-to-7-segment decoding logic with transparent latch functionality: data is latched on the rising edge of LE when BL is high. Its internal logic includes priority encoding where LT overrides BL and LE, enabling forced segment-on testing independent of input code.

Segment outputs are open-drain N-channel MOSFETs rated for 18 V sink capability and 25 mA continuous current, allowing direct drive of common-cathode LEDs without external transistors. The device uses standard CMOS silicon-gate technology with Schmitt-trigger inputs on LT, BL, and LE for noise immunity in noisy industrial settings.

Key Specifications

Pinout & Package

CD4511BF3A is supplied in a 16-lead hermetic ceramic dual-in-line package (CDIP-J), with 0.3-inch body width, 0.1-inch lead pitch, and through-hole mounting compatibility. The package meets MIL-STD-883 requirements for mechanical and environmental robustness.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC14511B and CD4511BE, the CD4511BF3A uniquely combines hermetic reliability, active production status, and full TI lifecycle support-making it the preferred choice for new designs requiring assured long-term availability and extreme-environment qualification.

Availability

CD4511BF3A is available at Aetrix Electronics and suitable for digital instrumentation, industrial process controllers, aerospace cockpit displays, and test equipment requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for CD4511BF3A 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 experience in high-reliability and industrial-grade components.

The CD4511BF3A belongs to TI's CD4000-series CMOS logic family, engineered for low-power, wide-voltage-operation digital interface functions in mission-critical instrumentation and control systems.

FAQ

What is the maximum segment current rating for CD4511BF3A?

The CD4511BF3A specifies a continuous output sink current of 25 mA per segment (pins 9–15) at V_DD = 15 V and T_A = 25°C. This rating allows direct drive of standard common-cathode LEDs without external drivers. Derating applies above 70°C ambient; consult Figure 9 in the SCHS072B datasheet for thermal limits. The CD4511BF3A maintains this performance across its full –55°C to +125°C operating range when properly heatsinked or used within SOA boundaries.

Does CD4511BF3A support multiplexed 7-segment displays?

Yes, the CD4511BF3A supports multiplexed displays when used with external timing circuitry. Its latch enable (LE) input allows synchronous capture of BCD data, while blanking (BL) provides precise segment-off control between digit scans. Because outputs are open-drain, multiple CD4511BF3A devices can share a common anode supply rail with individual digit cathodes switched by external transistors-enabling efficient 4-digit or larger multiplexed implementations without display ghosting.

Is CD4511BF3A pin-compatible with CD4511BE?

No-while the CD4511BF3A and CD4511BE share identical logic functionality and pin assignments, they differ in package type: CD4511BF3A uses a hermetic ceramic DIP (CDIP-J), whereas CD4511BE uses plastic DIP (PDIP-N). Mechanical dimensions, lead finish (SNPB vs. NIPDAU), moisture sensitivity, and thermal characteristics differ significantly. PCB footprints are not interchangeable; separate land patterns are required for each package variant.

What is the purpose of the Lamp Test (LT) input on CD4511BF3A?

The Lamp Test (LT) input on CD4511BF3A is an active-low signal that forces all seven segment outputs (a–g) to conduct simultaneously-regardless of BCD input, latch state, or blanking condition. This enables rapid hardware-level verification of LED continuity, wiring integrity, and display visibility during manufacturing test or field maintenance. The CD4511BF3A asserts LT independently of other controls, making it ideal for built-in self-test (BIST) sequences without firmware involvement.

Can CD4511BF3A operate from a 3.3 V supply?

Yes, the CD4511BF3A is fully specified to operate from 3 V to 18 V, including 3.3 V nominal supplies. At V_DD = 3.3 V, output sink current drops to approximately 4 mA per segment (per Figure 7 in SCHS072B), sufficient for low-current LEDs or optical couplers. Input thresholds scale with V_DD, ensuring reliable TTL- and CMOS-level compatibility. For 3.3 V systems, verify segment brightness requirements and consider adding series resistors to limit current to safe LED levels when using the CD4511BF3A.