Texas Instruments CD4028BNSR

Overview

CD4028BNSR from Texas Instruments is a BCD-to-decimal decoder/driver IC in a 16-pin SOP (NS) package, operating over −55°C to +125°C, with TTL-compatible input thresholds and CMOS-level output drive. It converts 4-bit binary-coded decimal inputs into ten active-high decimal outputs, enabling direct LED or relay interface in industrial control panels and digital instrumentation.

For engineers reviewing the CD4028BNSR datasheet, CD4028BNSR pinout, CD4028BNSR application, or CD4028BNSR equivalent, key selection factors include its wide temperature range, low quiescent current (≤1 µA at V_DD = 5 V), single-supply operation (3–18 V), and compatibility with legacy CD4000-series logic families.

Technical Context

The CD4028BNSR implements combinational logic decoding using standard CMOS gate arrays, with no internal latching or clocking-outputs respond asynchronously to input changes. All ten decoded outputs are fully buffered, each capable of sourcing/sinking ≥4.2 mA at V_DD = 15 V and 25°C.

Input logic levels are referenced to V_DD, with guaranteed high-level input voltage ≥0.7×V_DD and low-level input voltage ≤0.3×V_DD; output high/low voltage specs meet CD4000B-series standards across the full supply and temperature range.

Key Specifications

Pinout & Package

SOP-16 (NS) package: 10.4 mm × 5.3 mm body, 1.27 mm pitch, 2.00 mm max height, gull-wing leads, RoHS-compliant NiPdAu finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CD4028BM96 and CD4028BPWR, the CD4028BNSR offers identical electrical performance in a mid-density SOP-16 package optimized for mainstream SMT lines-balancing ease of assembly, thermal performance, and footprint compatibility with legacy NS-series footprints.

Availability

CD4028BNSR is available at Aetrix Electronics and suitable for industrial panel meters, digital test equipment, automotive instrument clusters, and legacy industrial controllers requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for CD4028BNSR 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 with over 90 years of analog and logic IC innovation, headquartered in Dallas, Texas.

The CD4028BNSR belongs to TI's legacy CD4000B logic family-designed for robust, low-power, wide-supply-voltage digital interfacing in industrial, automotive, and instrumentation systems where reliability and longevity are critical.

FAQ

What is the maximum supply voltage rating for CD4028BNSR?

The CD4028BNSR is rated for continuous operation up to 18 V DC on V_DD, with absolute maximum ratings specifying 20 V for short-duration transients. Operating above 18 V risks permanent damage to the oxide layers and is not supported by TI's qualification testing. The CD4028BNSR maintains full functionality and timing specifications across the entire 3–18 V range, making it suitable for unregulated battery or rectified AC supplies.

Does CD4028BNSR have built-in input hysteresis or Schmitt-trigger inputs?

No, the CD4028BNSR does not include Schmitt-trigger inputs or internal hysteresis. Its input thresholds are standard CMOS: V_IH ≥ 0.7×V_DD and V_IL ≤ 0.3×V_DD. For noisy environments, external RC filtering or discrete Schmitt buffers (e.g., CD40106) should be used before the CD4028BNSR inputs. This behavior is consistent across all CD4028B variants and documented in the TI SCHS033C datasheet Section 6.1.

Can CD4028BNSR drive LEDs directly without external transistors?

Yes, the CD4028BNSR can drive standard 2 mA–5 mA LEDs directly when used with appropriate series current-limiting resistors. At V_DD = 15 V, each output can sink ≥4.2 mA while maintaining V_OL < 0.5 V. For example, a 2.2 kΩ resistor with a red LED (V_F ≈ 1.8 V) yields ~6 mA drive-within safe limits. Always verify total package power dissipation (<100 mW) when multiple outputs are active simultaneously.

Is CD4028BNSR pin-compatible with the older CD4028BE (PDIP-16) version?

Yes, the CD4028BNSR is functionally and pinout-compatible with the CD4028BE PDIP-16 variant-the signal assignments, power pins, and logic behavior are identical. However, the physical package differs: NSR uses SOP-16 (surface-mount), while BE uses PDIP-16 (through-hole). No PCB redesign is needed if migrating from BE to NSR using a drop-in SOP-to-DIP adapter, but direct replacement requires footprint revision.

What happens when an invalid BCD code (1010–1111) is applied to CD4028BNSR inputs?

When invalid BCD codes (1010 through 1111) are applied to the CD4028BNSR inputs, all ten decimal outputs (0–9) remain low-no output is asserted. This behavior is explicitly defined in the truth table of the TI SCHS033C datasheet. The CD4028BNSR does not float or enter an undefined state; it guarantees zero active outputs for non-decimal inputs, simplifying error-handling logic in safety-critical displays.