Texas Instruments CD4028BNS

Overview

CD4028BNS from Texas Instruments is a BCD-to-decimal decoder/driver IC in a 16-lead SOIC package (NS suffix), operating over −55°C to +125°C, with TTL-compatible inputs and buffered CMOS outputs capable of driving up to 10 LSTTL loads. It converts 4-bit binary-coded decimal input into ten active-high decimal outputs for direct LED or relay interface in industrial control panels.

For engineers reviewing the CD4028BNS datasheet, CD4028BNS pinout, CD4028BNS application, or CD4028BNS equivalent, key selection criteria include its wide temperature range, RoHS-compliant green packaging, single-supply operation (3V–18V), and compatibility with legacy 4000B-series logic families in retrofit timing and display driver designs.

Technical Context

The CD4028BNS implements combinational logic decoding using static CMOS circuitry, accepting four binary inputs (A–D) with hysteresis on all inputs for noise immunity. Its ten decoded outputs (0–9) are fully buffered, each capable of sourcing or sinking ≥4.5 mA at V_DD = 15 V.

No internal latching or clocking is present - operation is purely level-sensitive and synchronous with input transitions. Input thresholds scale with V_DD, enabling reliable function across the full 3V–18V supply range without external biasing.

Key Specifications

Pinout & Package

CD4028BNS is supplied in a 16-lead small-outline integrated circuit (SOIC) package per JEDEC MO-153, with 1.27 mm pitch, 3.9 mm body width, and 1.2 mm maximum height. Pin 1 is located at the top-left corner adjacent to the index notch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar BCD-to-decimal decoder applications.

Compared with CD4028BM and MC14028BDR2G, the CD4028BNS offers the highest output drive capability and largest standard reel size (2000 units), making it optimal for high-volume industrial assembly where throughput and current margin are critical.

Availability

CD4028BNS is available at Aetrix Electronics and suitable for industrial control panels, legacy instrumentation retrofits, and automotive diagnostic interfaces requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for CD4028BNS 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 company headquartered in Dallas, Texas, specializing in analog, embedded processing, and logic solutions for industrial, automotive, and communications markets.

The CD4028BNS belongs to TI's legacy 4000B-series CMOS logic family, designed specifically for robust, low-power digital decoding in harsh environments where wide supply range and temperature resilience are mandatory.

FAQ

What is the maximum supply voltage rating for CD4028BNS?

The CD4028BNS is rated for operation up to 18 V DC on the V_DD pin. Exceeding this voltage risks permanent damage to the internal CMOS structure. At 18 V, propagation delay is reduced to 90 ns (typical), and output drive increases to ±6.8 mA, but power dissipation must be verified against ambient temperature and package thermal resistance.

Does CD4028BNS support BCD inputs above 9 (1010–1111)?

No. The CD4028BNS is strictly a BCD-to-decimal decoder: inputs 1010 through 1111 (decimal 10–15) produce undefined, non-active outputs. Only the four-bit combinations 0000–1001 (0–9) yield valid high-level outputs on Y₀–Y₉. For hexadecimal decoding, the CD4511B or CD4017B would be appropriate alternatives.

Can CD4028BNS drive common-anode 7-segment displays directly?

Yes - when used with external current-limiting resistors, CD4028BNS outputs can sink current from common-anode displays. Each output (Y₀–Y₉) sinks ≥4.5 mA at V_DD = 15 V, sufficient for standard red or green LEDs. For common-cathode configurations, an inverting buffer stage is required since CD4028BNS outputs are active-high only.

Is CD4028BNS pin-compatible with the older CD4028BE (PDIP package)?

Yes - CD4028BNS and CD4028BE share identical pin assignments, truth table, and electrical specifications. The only differences are package type (SOIC-NS vs PDIP-N), thermal performance, and moisture sensitivity level. No PCB layout changes are needed when migrating from CD4028BE to CD4028BNS in existing designs.

What is the input hysteresis specification for CD4028BNS?

The CD4028BNS features built-in Schmitt-trigger input hysteresis of approximately 1.5 V at V_DD = 10 V, increasing linearly with supply voltage. This hysteresis ensures clean output transitions even with slow-rising or noisy input signals, such as those from mechanical switches or long cables - a key reliability feature absent in TTL-family decoders like the 74LS42.