MM74C926N LED Driver 7-Segment 4-Digit Equivalent & Substitute Parts

Part Overview

The MM74C926N is a 7-segment LED driver IC manufactured by onsemi, designed to drive 4-digit LED displays using BCD (Binary-Coded Decimal) interface. This component is classified as obsolete, which necessitates identification of functionally equivalent alternatives for new designs and production continuity. The part operates across a 3V to 6V supply range with minimal current draw of 20 µA, making it suitable for low-power display applications.

Substiute Parts

MM74C926N

onsemiIn Stock: 2267MM74C926N Datasheet

Current PartRFQ

CD74HC4543E

Texas InstrumentsIn Stock: 1766CD74HC4543E Datasheet

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CD74HCT4543E

Harris CorporationIn Stock: 28866CD74HCT4543E Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the MM74C926N is constrained by the following critical parameters:

• Display Configuration: 7-segment LED driver functionality
• Interface Protocol: BCD input compatibility
• Package Type: Through-hole DIP format
• Supply Voltage Range: Minimum overlap requirement of 3V to 6V
• Operating Temperature: Minimum range of -40°C to 85°C
• Mounting Compatibility: Through-hole mounting on standard PCB layouts

The identified substitute parts (CD74HC4543E and CD74HCT4543E) share the core 7-segment LED driver architecture and BCD interface. However, both substitute parts are rated for single-digit display operation rather than the 4-digit capability of the MM74C926N. This represents a functional limitation that must be evaluated against application requirements. Both substitutes maintain through-hole DIP packaging and BCD interface compatibility, enabling direct functional replacement in circuits where single-digit display operation is acceptable.

Parameter Comparison

Engineering Selection Recommendations

CD74HC4543E (Texas Instruments) is the preferred substitute option based on active product status and broader supply voltage compatibility (2V ~ 6V). This part maintains full BCD interface compatibility and 7-segment LED driver functionality. The extended operating temperature range (-55°C ~ 125°C) exceeds the original specification. The 16-DIP package is mechanically compatible with standard through-hole PCB layouts. RoHS3 compliance status provides regulatory alignment for modern manufacturing environments.

CD74HCT4543E (Harris Corporation) presents a secondary option with identical functional characteristics to the CD74HC4543E. However, this part carries obsolete product status, limiting long-term supply availability. The restricted supply voltage range (4.5V ~ 5.5V) narrows application flexibility compared to the CD74HC4543E. RoHS non-compliance status may present regulatory constraints in certain manufacturing contexts.

Both substitute parts operate at reduced supply current (8 µA versus 20 µA), providing improved power efficiency. The single-digit display limitation requires circuit redesign if 4-digit display capability is mandatory for the application.

Frequently Asked Questions (FAQ)

Q: Can CD74HC4543E directly replace MM74C926N in existing designs?

A: Functional replacement is possible with circuit modification. Both parts share BCD interface protocol and 7-segment LED driver architecture. The primary constraint is display digit capacity: CD74HC4543E drives single-digit displays while MM74C926N drives 4-digit displays. PCB layout modifications may be required to accommodate the 16-DIP package versus the original 18-DIP package.

Q: What are the voltage compatibility considerations?

A: MM74C926N operates across 3V to 6V. CD74HC4543E supports 2V to 6V, providing broader low-voltage compatibility. CD74HCT4543E is restricted to 4.5V to 5.5V, limiting operation in 3V systems. Verify system supply voltage against substitute part specifications before selection.

Q: Are the DIP packages mechanically interchangeable?

A: Both substitute parts use 16-DIP through-hole packages with 0.300" (7.62mm) row spacing, matching standard DIP socket specifications. The MM74C926N uses 18-DIP packaging. PCB footprint redesign is required if socket-based replacement is intended. Direct soldering to existing 18-DIP footprints is not recommended.

Q: What compliance certifications apply to substitute parts?

A: CD74HC4543E carries RoHS3 compliance certification. CD74HCT4543E is RoHS non-compliant. Both parts maintain EAR99 export classification and REACH unaffected status. Verify compliance requirements against your manufacturing and distribution standards.

Q: How do supply current specifications compare?

A: MM74C926N draws 20 µA supply current. Both CD74HC4543E and CD74HCT4543E draw 8 µA, representing 60% current reduction. This improvement benefits battery-powered and low-power applications.