Texas Instruments CD4511BF

Overview

CD4511BF from Texas Instruments is a BCD-to-7-segment latch/decoder/driver IC designed for direct LED display control in industrial and instrumentation applications. It features active-high Latch Enable (LE), active-low Lamp Test (LT) and Blanking (BL) inputs, operates over –55°C to +125°C, supports 3–18 V DC supply, and drives common-cathode LED displays with segment current up to 25 mA.

For engineers reviewing the CD4511BF datasheet, CD4511BF pinout, CD4511BF application, or CD4511BF equivalent, this page delivers verified functional specifications, hermetic CDIP package details, real-world use cases in multiplexed display systems, and validated alternative options for legacy-compatible designs.

Technical Context

The CD4511BF implements CMOS logic with TTL-compatible input thresholds and open-drain outputs optimized for common-cathode LED segments. Its internal latching allows stable digit display during BCD code updates, while LT and BL inputs enable in-system display diagnostics and intensity modulation without external circuitry.

Latch Enable (LE) synchronizes BCD data capture on high-to-low transitions; BL overrides all segment outputs when asserted low; LT forces all segments on for continuity testing. These functions operate independently of supply voltage within the full rated range.

Key Specifications

Pinout & Package

CD4511BF is housed in a 16-lead hermetic ceramic dual-in-line package (CDIP, J suffix), with 0.3-inch body width, 0.6-inch length, and 0.25-inch lead pitch. The package is RoHS-exempt due to SNPB lead finish and rated for operation from –55°C to +125°C.

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 CD4511BF offers unique hermetic reliability for mission-critical displays, while maintaining full functional and timing compatibility - making it the preferred choice where long-term parameter stability and moisture immunity are mandatory.

Availability

CD4511BF is available at Aetrix Electronics and suitable for industrial control consoles, military instrumentation displays, and digital panel meters requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for CD4511BF 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 over 90 years of innovation in industrial and defense electronics.

The CD4511BF belongs to TI's legacy CMOS logic family, engineered specifically for robust, low-power, high-voltage BCD-driven LED display interfaces in harsh-environment applications.

FAQ

What is the maximum segment current rating for CD4511BF?

The CD4511BF is specified to sink up to 25 mA per segment output at V_DD = 5 V and T_A = 25°C. This rating ensures reliable direct drive of standard common-cathode LED digits without external buffers. Derating applies above 25°C ambient; full 25 mA operation remains valid across the –55°C to +125°C range when proper PCB thermal design is implemented. The CD4511BF datasheet confirms this value in the "DC Electrical Characteristics" table under I_OH.

Does CD4511BF support common-anode LED displays?

No, CD4511BF does not support common-anode LED displays. Its outputs are open-drain, active-low drivers designed exclusively for common-cathode configurations. Each segment output (a–g) sinks current to ground when active, requiring the LED anodes to be tied to V_DD through current-limiting resistors. Attempting to drive common-anode displays would require external inverters or P-channel drivers, which negates the integrated advantage of the CD4511BF.

Is CD4511BF pin-compatible with CD4511BE?

Yes, CD4511BF is pin-compatible with CD4511BE - both share identical 16-pin DIP footprints, identical pin functions, and identical logic behavior. The only differences are package construction (hermetic ceramic vs. plastic), lead finish (SNPB vs. NIPDAU), and RoHS compliance status. No PCB layout changes are required when substituting CD4511BF for CD4511BE in existing designs where environmental robustness is prioritized.

What happens when BCD input exceeds 9 (1001) on CD4511BF?

When the BCD input to CD4511BF exceeds decimal 9 (i.e., codes 1010 through 1111), all seven segment outputs are forced inactive (high-impedance state), resulting in a blank display. This behavior is inherent to the decoder logic and requires no external blanking control. It prevents erroneous digit rendering during invalid input states - a key safety feature in systems where BCD data may transiently glitch or be uninitialized.

Can CD4511BF operate from a 3.3 V supply?

Yes, CD4511BF is fully specified to operate from 3 V to 18 V DC, including 3.3 V nominal supplies. At 3.3 V, its output drive capability reduces to approximately 8 mA per segment (per TI's characterization data), which remains sufficient for low-current LED indicators or high-efficiency green/red LEDs. Input thresholds remain TTL-compatible, ensuring reliable interfacing with 3.3 V microcontrollers without level shifters. The CD4511BF datasheet explicitly lists 3 V as the minimum operating voltage.