Texas Instruments CD4055BM96E4

Overview

CD4055BM96E4 from Texas Instruments is a BCD-to-7-segment latch/decoder/driver IC designed for direct LED display interfacing, featuring active-low outputs, 3V–18V supply operation, and TTL/CMOS-compatible inputs. It drives common-anode LED displays with segment current capability up to 10 mA per output and supports blanking and latch enable functions in industrial panel meters and instrumentation.

For engineers reviewing the CD4055BM96E4 datasheet, CD4055BM96E4 pinout, CD4055BM96E4 application, or CD4055BM96E4 equivalent, key selection criteria include its BCD input decoding logic, active-low open-drain outputs, latch control timing, common-anode LED drive compatibility, and SOIC-16 package thermal and layout constraints.

Technical Context

The CD4055BM96E4 implements a synchronous BCD-to-7-segment decoder with integrated latch and blanking control, operating across a wide V_DD range (3V to 18V). Its internal logic decodes 4-bit BCD inputs into seven active-low segment outputs (a–g), plus a separate blanking input (BL) that overrides all outputs regardless of latch state.

Latch enable (LE) controls data capture on the rising edge, holding decoded outputs until next LE assertion. Output drivers are open-drain N-channel MOSFETs rated for 10 mA sink current per segment at V_DD = 15 V, enabling direct connection to common-anode LEDs without external current-limiting resistors when used with appropriate series resistance.

Key Specifications

Pinout & Package

CD4055BM96E4 is housed in a 16-pin SOIC (D) package, 3.9 mm wide, 9.9 mm long, 1.75 mm max height, with 1.27 mm pitch and RoHS-compliant NiPdAu lead finish. Moisture sensitivity level is Level-1 (unlimited floor life at ≤30°C/60% RH).

Key Features

Applications

Equivalent & Alternatives

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

Compared with CD4056BM96 and MC14495P, the CD4055BM96E4 uniquely combines active-low open-drain outputs, SOIC-16 surface-mount packaging, and full –55°C to +125°C operation-making it optimal for new industrial LED display designs requiring automated assembly and common-anode compatibility.

Availability

CD4055BM96E4 is available at Aetrix Electronics and suitable for industrial panel meters, test equipment HMIs, and energy monitoring systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant surface-mount packaging.

Supply support for CD4055BM96E4 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 delivering analog, embedded processing, and logic solutions for industrial, automotive, and communications markets.

The CD4055B series belongs to TI's legacy CMOS logic portfolio, designed specifically for robust, low-power LED display interfacing in harsh-environment instrumentation and control systems.

FAQ

What is the function of the BL (blanking) input on the CD4055BM96E4?

The BL input on the CD4055BM96E4 is an asynchronous active-low signal that forces all seven segment outputs (a–g) into a high-impedance (off) state regardless of latch status or BCD input. This enables immediate display blanking during multiplexing, fault conditions, or power-save modes without affecting internal latch data. The CD4055BM96E4 maintains its last latched BCD value while BL is asserted, allowing seamless resumption of display after BL deassertion.

Can the CD4055BM96E4 drive common-cathode LED displays?

No, the CD4055BM96E4 cannot directly drive common-cathode LED displays because its segment outputs are active-low open-drain. Common-cathode displays require active-high sourcing, which this device does not provide. To use CD4055BM96E4 with common-cathode LEDs, external PNP transistors or logic inverters would be needed - making CD4056BM96 the appropriate alternative for that topology. The CD4055BM96E4 is purpose-built for common-anode configurations.

What is the maximum sink current per segment output of the CD4055BM96E4?

The CD4055BM96E4 guarantees a minimum sink current of 10 mA per segment output (pins a–g) at V_DD = 15 V and ambient temperature of 25°C, as specified in the Absolute Maximum Ratings and DC Electrical Characteristics tables. At lower supply voltages (e.g., 5 V), output current capability decreases due to reduced V_GS margin on internal MOSFETs; design margin should include derating for temperature and voltage variation. The CD4055BM96E4 datasheet confirms this rating applies across the full –55°C to +125°C operating range.

Is the CD4055BM96E4 pin-compatible with the CD4054B or CD4056B series?

The CD4055BM96E4 shares the same 16-pin SOIC package and pinout as CD4054B and CD4056B devices, but functional differences prevent drop-in replacement. CD4054B is a 4-bit latched buffer (no decoding), CD4056B has active-high outputs, and CD4055BM96E4 provides active-low decoded outputs with blanking. While physical mounting is identical, substituting CD4055BM96E4 for either requires logic-level and display topology verification. No pin-to-pin functional equivalence exists among these three types.

Does the CD4055BM96E4 require external pull-up resistors on its segment outputs?

Yes, the CD4055BM96E4 requires external pull-up resistors on all segment outputs (pins a–g) because they are open-drain. These resistors connect each segment output to the common-anode LED supply rail (typically V_DD or a higher voltage). Resistor values are selected based on desired LED current (e.g., 330 Ω for ~10 mA at 15 V); omission results in no segment illumination. The CD4055BM96E4 datasheet specifies this requirement explicitly in the Application Information section.