74AC74PC Equivalent & Substitute Parts

Part Overview

The 74AC74PC is a dual D-type flip-flop logic integrated circuit in 14-DIP packaging, manufactured by onsemi. This component provides two independent D-type flip-flops with Set (Preset) and Reset functions, complementary outputs, and positive edge triggering. The part is currently listed as obsolete, making equivalent substitute parts necessary for ongoing design support and procurement.

Substiute Parts

74AC74PC

onsemiIn Stock: 151074AC74PC Datasheet

Current PartRFQ

SN74AC74N

Texas InstrumentsIn Stock: 1342SN74AC74N Datasheet

DirectRFQ

CD74AC74E

Harris CorporationIn Stock: 1507CD74AC74E Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 74AC74PC is determined by the following critical parameters:

Core Functional Requirements:

• Series: 74AC (Advanced CMOS logic family)
• Type: D-Type Flip-Flop
• Number of Elements: 2
• Number of Bits per Element: 1
• Output Type: Complementary
• Trigger Type: Positive Edge
• Function: Set (Preset) and Reset capability

Electrical Compatibility Parameters:

• Clock Frequency: minimum 160 MHz
• Max Propagation Delay @ 5V, 50pF: maximum 10 ns
• Voltage Supply Range: must encompass 2V ~ 6V or be compatible within this range
• Current Output High/Low: 24 mA / 24 mA
• Operating Temperature Range: must support -40°C ~ 85°C minimum

Physical Compatibility:

• Package / Case: 14-DIP (0.300", 7.62mm)
• Mounting Type: Through Hole

Substitute parts must maintain identical functional architecture, electrical performance within specified limits, and physical pin compatibility to ensure direct replacement capability.

Parameter Comparison

Engineering Selection Recommendations

SN74AC74N (Texas Instruments) is the primary recommended substitute for the 74AC74PC. This part maintains identical functional specifications, electrical performance, and physical packaging. The SN74AC74N is currently in active production status, ensuring long-term availability and supply chain stability. Texas Instruments provides full RoHS3 compliance, meeting modern environmental and regulatory requirements. The lower quiescent current (2 µA versus 20 µA) and reduced input capacitance (3 pF versus 4.5 pF) represent improved power efficiency characteristics while maintaining full electrical compatibility.

CD74AC74E (Harris Corporation) is an alternative substitute that meets core functional and electrical requirements. This part maintains the same propagation delay and output current specifications. However, the CD74AC74E operates at a reduced clock frequency of 110 MHz compared to the 160 MHz specification of the 74AC74PC, and is listed as obsolete. The extended operating temperature range (-55°C ~ 125°C) and broader voltage supply range (1.5V ~ 5.5V) provide additional environmental flexibility. The CD74AC74E is not RoHS compliant. Selection of this part should be limited to applications where the reduced clock frequency is acceptable and long-term availability is not a primary concern.

Frequently Asked Questions (FAQ)

Q: Can the SN74AC74N directly replace the 74AC74PC in existing designs?

A: Yes. The SN74AC74N maintains identical pin configuration, functional architecture, and electrical performance specifications within the 14-DIP package. Direct socket replacement is supported without circuit modification.

Q: What is the significance of the clock frequency difference between the 74AC74PC and CD74AC74E?

A: The 74AC74PC operates at 160 MHz maximum clock frequency, while the CD74AC74E is rated for 110 MHz. In applications operating below 110 MHz, the CD74AC74E is functionally compatible. Applications requiring operation above 110 MHz must use the 74AC74PC or SN74AC74N.

Q: Why is the SN74AC74N preferred over the CD74AC74E?

A: The SN74AC74N is in active production status, ensuring reliable long-term availability and supply chain support. The CD74AC74E is obsolete and may face procurement challenges. Additionally, the SN74AC74N meets RoHS3 compliance requirements, while the CD74AC74E does not.

Q: Are there package or pinout differences between these parts?

A: No. All three parts use identical 14-DIP (0.300", 7.62mm) through-hole packaging with matching pin configurations and mechanical dimensions.

Q: What are the quiescent current implications of substitution?

A: The 74AC74PC draws 20 µA quiescent current, while the SN74AC74N draws 2 µA and the CD74AC74E draws 4 µA. In battery-powered or low-power applications, the SN74AC74N provides superior power efficiency. This difference is not a functional incompatibility but represents an operational advantage.

Q: Can the CD74AC74E be used in applications requiring the full -40°C ~ 85°C temperature range?

A: Yes. The CD74AC74E operating range of -55°C ~ 125°C encompasses the -40°C ~ 85°C requirement of the 74AC74PC. Temperature range compatibility is satisfied.