MM74C928N Equivalent & Substitute Parts

Part Overview

The MM74C928N is a 7-segment LED driver manufactured by onsemi, designed to control 4-digit LED displays using BCD (Binary Coded Decimal) interface. This device operates across a 3V to 6V supply range with minimal current draw of 20 µA. The MM74C928N is classified as obsolete, making equivalent substitute parts necessary for new designs, maintenance applications, or when original stock becomes unavailable.

Substiute Parts

MM74C928N

onsemiIn Stock: 883MM74C928N Datasheet

Current PartRFQ

CD74HC4543E

Texas InstrumentsIn Stock: 1766CD74HC4543E Datasheet

SimilarRFQ

CD74HCT4543E

Harris CorporationIn Stock: 28866CD74HCT4543E Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the MM74C928N is determined by the following critical parameters:

• Display Type & Configuration: Both substitute parts maintain LED 7-segment decoder/driver functionality
• Interface Protocol: BCD input compatibility is preserved across all listed parts
• Mounting Type: All parts use through-hole mounting with DIP packaging
• Supply Voltage Range: Substitute parts must operate within overlapping voltage specifications
• Operating Temperature Range: Substitute parts must support the required thermal envelope
• Package Compatibility: Physical DIP package dimensions must accommodate existing PCB layouts

The CD74HC4543E and CD74HCT4543E are functionally equivalent BCD-to-7-segment decoder/drivers. However, key differences exist in digit capacity (1 digit vs. 4 digits), supply current characteristics, and voltage operating ranges. These differences require engineering evaluation based on specific application requirements.

Parameter Comparison

Engineering Selection Recommendations

CD74HC4543E (Texas Instruments): This part is currently active and maintains ROHS3 compliance. It offers extended operating temperature range (-55°C to 125°C) and lower supply current (8 µA). The voltage range of 2V to 6V provides broader compatibility than the original MM74C928N. However, this device is rated for single-digit display control, requiring multiple units for multi-digit applications.

CD74HCT4543E (Harris Corporation): This part is obsolete with RoHS non-compliance status. The voltage range is restricted to 4.5V to 5.5V, which is narrower than the MM74C928N specification. While it shares the same operating temperature range and single-digit configuration as the CD74HC4543E, its obsolete status and compliance limitations make it less suitable for new designs.

For applications requiring 4-digit display control with the MM74C928N's original functionality, multiple CD74HC4543E units would be required, necessitating circuit redesign. For single-digit applications, the CD74HC4543E provides an active, compliant alternative.

Frequently Asked Questions (FAQ)

Q: Can the CD74HC4543E directly replace the MM74C928N in existing designs?

A: Direct pin-for-pin replacement is not possible. The MM74C928N controls 4 digits in a single package, while the CD74HC4543E controls 1 digit. The MM74C928N uses an 18-DIP package, and the CD74HC4543E uses a 16-DIP package. Circuit redesign is required for substitution.

Q: What is the key functional difference between these parts?

A: All three parts are BCD-to-7-segment decoder/drivers for LED displays. The primary difference is digit capacity: the MM74C928N handles 4 digits, while both substitute parts handle 1 digit each. This affects circuit architecture and component count in multi-digit display applications.

Q: Are the voltage supply ranges compatible?

A: The CD74HC4543E operates from 2V to 6V, which encompasses the MM74C928N range of 3V to 6V. The CD74HCT4543E operates from 4.5V to 5.5V, which is a subset of the MM74C928N range. Applications using 3V to 4.5V supplies cannot use the CD74HCT4543E.

Q: Which substitute part is recommended for new designs?

A: The CD74HC4543E is recommended for new designs due to its active product status and ROHS3 compliance. The CD74HCT4543E should be avoided in new designs due to obsolete status and RoHS non-compliance.

Q: Do package dimensions affect substitution feasibility?

A: Yes. The MM74C928N uses an 18-DIP package while both substitutes use 16-DIP packages. Although both are 0.300" (7.62mm) pitch DIP packages, the different pin counts require PCB layout modifications. Existing through-hole footprints designed for 18-DIP cannot accommodate 16-DIP packages without redesign.