MM74HCT273N Equivalent & Substitute Parts

Part Overview

The MM74HCT273N is a Flip Flop 1 Element D-Type 8 Bit Positive Edge triggered logic integrated circuit in 20-DIP (0.300", 7.62mm) through-hole packaging. Manufactured by onsemi, this component features Master Reset functionality with non-inverted outputs and operates across the 4.5V to 5.5V supply voltage range. The part is currently listed as obsolete, making equivalent substitutes necessary for ongoing system maintenance, repair, and legacy design support.

Substiute Parts

MM74HCT273N

onsemiIn Stock: 1142MM74HCT273N Datasheet

Current PartRFQ

CD74HCT273E

Harris CorporationIn Stock: 3271CD74HCT273E Datasheet

SimilarRFQ

SN74HCT273N

Texas InstrumentsIn Stock: 3899SN74HCT273N Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the MM74HCT273N is determined by strict adherence to the following electrical and mechanical parameters:

Critical Matching Parameters:

• Base Product Number: 74HCT273 (identical logic family and pinout)
• Package / Case: 20-DIP (0.300", 7.62mm) (identical physical form factor)
• Type: D-Type Flip Flop (identical functional architecture)
• Number of Elements: 1 (identical element count)
• Number of Bits per Element: 8 (identical bit width)
• Function: Master Reset (identical control functionality)
• Output Type: Non-Inverted (identical output configuration)
• Trigger Type: Positive Edge (identical clock edge sensitivity)
• Mounting Type: Through Hole (identical board integration method)
• Voltage - Supply: 4.5V ~ 5.5V (identical supply voltage range)

All identified substitute parts meet these critical parameters, ensuring direct functional and physical compatibility without circuit redesign or board modification.

Parameter Comparison

Engineering Selection Recommendations

SN74HCT273N (Texas Instruments) is the preferred substitute for new designs and ongoing production. This part maintains active product status, ensuring long-term availability and supply chain stability. The SN74HCT273N is ROHS3 compliant, meeting current environmental and regulatory requirements. Electrical performance remains within acceptable parameters for 74HCT273 applications, with propagation delay of 29ns at 5.5V and 50pF load.

CD74HCT273E (Harris Corporation) is a functional equivalent suitable for direct replacement in existing systems where the MM74HCT273N is no longer available. This part offers extended operating temperature range (-55°C to 125°C) compared to the original specification, providing additional thermal margin in demanding environments. However, RoHS non-compliance status should be evaluated against system-level regulatory requirements.

Both substitute parts share identical pinout, package form factor, and core electrical characteristics with the MM74HCT273N, enabling direct socket substitution without circuit modification.

Frequently Asked Questions (FAQ)

Q: Can the SN74HCT273N directly replace the MM74HCT273N without circuit modification?

A: Yes. The SN74HCT273N is a direct pin-for-pin replacement. Both parts use the 20-DIP package, identical pinout, and compatible electrical specifications within the 4.5V to 5.5V supply range. No circuit redesign is required.

Q: What is the primary difference between the three substitute options?

A: Product status and compliance certifications differ. The SN74HCT273N (Texas Instruments) is active and ROHS3 compliant. The CD74HCT273E (Harris) and MM74HCT273N (onsemi) are both obsolete. The CD74HCT273E offers extended temperature range (-55°C to 125°C) versus the standard -40°C to 85°C range.

Q: Are there performance differences in propagation delay between these parts?

A: Propagation delays vary slightly: MM74HCT273N at 37ns (5V, 50pF), CD74HCT273E at 30ns (4.5V, 50pF), and SN74HCT273N at 29ns (5.5V, 50pF). All values remain within acceptable operating margins for standard 74HCT logic applications.

Q: Which substitute should be selected for new production?

A: The SN74HCT273N is recommended for new production due to active product status and ROHS3 compliance, ensuring supply continuity and regulatory alignment.

Q: Is the 20-DIP package form factor identical across all three parts?

A: Yes. All three parts use the 20-DIP (0.300", 7.62mm) through-hole package with identical pinout and physical dimensions, enabling direct board-level substitution.

Q: What is the significance of the 74HCT273 base product number?

A: The base product number identifies the core logic function and pinout standard. All three parts share this designation, confirming functional equivalence and interchangeability within the 74HCT logic family.