74HCT393N Binary Counter IC Equivalent & Substitute Parts

Part Overview

The 74HCT393N is a dual 4-bit binary counter IC manufactured by NXP USA Inc., designed for digital logic applications requiring asynchronous counting functionality. This component features two independent 4-bit counters with negative edge triggering and operates across a supply voltage range of 4.5 V to 5.5 V. The part is classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing system maintenance, legacy equipment repair, and design continuity in applications where this specific counter architecture is required.

Substiute Parts

74HCT393N,652

NXP USA Inc.In Stock: 90074HCT393N,652 Datasheet

Current PartRFQ

CD74HCT393E

Harris CorporationIn Stock: 2203CD74HCT393E Datasheet

DirectRFQ

SN74LS393N

Texas InstrumentsIn Stock: 3376SN74LS393N Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 74HCT393N is determined by strict alignment with the following core parameters:

• Logic Architecture: Binary counter with 2 elements, 4 bits per element, up-counting direction
• Trigger Mechanism: Negative edge triggering
• Reset Function: Asynchronous reset capability
• Physical Interface: 14-DIP through-hole package (0.300", 7.62mm pitch)
• Electrical Compatibility: Supply voltage range and operating temperature envelope

The identified substitute parts maintain functional equivalence across these critical parameters. Variations in count rate, supply voltage tolerance, and operating temperature range are permissible within the constraints of the target application's electrical and thermal specifications.

Parameter Comparison

Engineering Selection Recommendations

CD74HCT393E (Harris Corporation): This substitute maintains identical series classification (74HCT) and electrical specifications within the 4.5 V to 5.5 V supply range. However, the part is classified as obsolete and RoHS non-compliant, limiting its applicability in new designs or regulated environments requiring environmental compliance documentation.

SN74LS393N (Texas Instruments): This substitute belongs to the 74LS logic family and maintains active product status, ensuring ongoing availability and supply chain continuity. The part is ROHS3 compliant and suitable for applications where environmental compliance is required. The operating temperature range is restricted to 0°C to 70°C, and supply voltage tolerance is narrower (4.75 V to 5.25 V) compared to the 74HCT series. The count rate of 35 MHz is lower than the primary part but remains adequate for standard digital logic applications. This option is preferred for new designs and legacy system replacements where compliance and availability are priorities.

Frequently Asked Questions (FAQ)

Q: Can the CD74HCT393E directly replace the 74HCT393N in existing circuits?

A: Yes, from a functional and electrical standpoint. Both parts operate within the same 4.5 V to 5.5 V supply range and share identical counter architecture. However, the CD74HCT393E is RoHS non-compliant and obsolete, which may conflict with procurement policies or regulatory requirements.

Q: What are the limitations of using SN74LS393N as a substitute?

A: The SN74LS393N operates within a narrower supply voltage range (4.75 V to 5.25 V) and restricted operating temperature range (0°C to 70°C). Applications requiring operation below 0°C or above 70°C, or with supply voltages below 4.75 V, must use the 74HCT series alternatives. The count rate of 35 MHz is lower than the 74HCT393N but sufficient for most standard logic applications.

Q: Are all three parts pin-compatible?

A: Yes. All three parts use the 14-DIP through-hole package with identical 0.300" (7.62mm) pitch, ensuring direct socket compatibility without PCB modifications.

Q: Which substitute is recommended for new designs?

A: The SN74LS393N is recommended for new designs due to its active product status, ROHS3 compliance, and assured long-term availability from Texas Instruments.

Q: Can these parts be used interchangeably in high-frequency applications?

A: The 74HCT393N and CD74HCT393E support higher count rates (107 MHz and 27 MHz respectively) compared to the SN74LS393N (35 MHz). For applications requiring operation above 35 MHz, the 74HCT series parts are necessary.