STMicroelectronics M74HC4028B1R

Overview

M74HC4028B1R from STMicroelectronics is a high-speed CMOS BCD-to-decimal decoder in 16-pin DIP package, operating from 2V to 6V supply, with typical propagation delay of 20ns at 6V, ±4mA output drive capability, and 4µA max quiescent current at 25°C. It decodes 4-bit BCD inputs (A–D) to activate one of ten active-high decimal outputs (Y0–Y9), supporting code conversion and memory address decoding in industrial control logic.

For engineers reviewing the M74HC4028B1R datasheet, M74HC4028B1R pinout, M74HC4028B1R application, or M74HC4028B1R equivalent, key selection criteria include BCD decoding accuracy, TTL/CMOS input compatibility, symmetrical output drive strength, wide VCC range tolerance, and DIP-16 through-hole mounting for legacy board designs.

Technical Context

The M74HC4028B1R implements combinational logic decoding using silicon gate C2MOS technology, with all inputs protected against ESD and transient overvoltage. Its truth table enforces strict BCD validity: only codes 0000–1001 (0–9) produce a single high output; illegal codes (1010–1111) force all Y0–Y9 low.

When input D is used as an enable/disable control, the device functions as a 3-to-8 line decoder with A–C as address bits. Propagation delays tPLH and tPHL are balanced (tPLH ≅ tPHL), and noise immunity is guaranteed at ≥28% VCC for both VIH and VIL thresholds across temperature.

Key Specifications

Pinout & Package

Package: Plastic Dual In-line Package (DIP-16), 0.3" wide, through-hole mount, JEDEC MS-001 compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with M74HC4028B1R, the NXP 74HC4028N offers near-identical performance with minor timing variance, while TI's CD74HC4028E trades 2× higher ICC for identical functionality and broader qualification coverage - choice depends on power budget vs. certification requirements.

Availability

M74HC4028B1R is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, legacy microcontroller address decoding, and automotive body control module designs requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for M74HC4028B1R 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing analog, digital, and mixed-signal ICs for industrial, automotive, and consumer markets.

The M74HC4028B1R belongs to ST's high-speed CMOS logic family, engineered for pin-compatible upgrades of obsolete 74LS devices while delivering lower power, wider voltage range, and enhanced noise immunity in industrial control systems.

FAQ

Is M74HC4028B1R compatible with 5V TTL logic inputs?

Yes. With VIH(min) = 3.15V and VIL(max) = 1.35V at VCC = 4.5V, it accepts standard 5V TTL output levels. Input thresholds scale with VCC, ensuring interoperability across 3.3V and 5V systems without level-shifting circuitry.

Can M74HC4028B1R operate reliably at 2.0V supply?

Yes. It meets all DC and AC specifications down to 2.0V, including VOH ≥1.9V and VOL ≤0.1V at 20µA load. Propagation delay increases to 96ns (typ.), but remains fully functional for low-speed control logic in battery-powered equipment.

What happens when non-BCD inputs (e.g., 1010) are applied?

All ten outputs (Y0–Y9) remain LOW for any input combination outside 0000–1001. This illegal-code suppression prevents erroneous activation of downstream circuits, such as unintended memory chip selects or relay activations, enhancing system fault tolerance.

Does M74HC4028B1R require external pull-up resistors on outputs?

No. Outputs are push-pull CMOS with ±4mA drive capability. Pull-ups are unnecessary unless interfacing with open-collector loads or implementing wired-OR logic - in standard BCD decoding, direct connection to LEDs or logic inputs is supported.