74HCT191D,652 Binary Counter - Equivalent & Substitute Parts

Part Overview

The 74HCT191D,652 is a 4-bit binary counter IC manufactured by NXP USA Inc., designed for synchronous up/down counting applications. This component features positive edge triggering, operates at a maximum count rate of 39 MHz, and is housed in a 16-SOIC surface mount package. The part is classified as obsolete, making identification of functionally equivalent substitutes essential for ongoing design support and production continuity.

Substiute Parts

74HCT191D,652

NXP USA Inc.In Stock: 97674HCT191D,652 Datasheet

Current PartRFQ

CD74HCT191M

Harris CorporationIn Stock: 8276CD74HCT191M Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 74HCT191D,652 is determined by strict equivalence across the following critical parameters:

• Logic Function: Binary counter with 4-bit capacity
• Counting Direction: Bidirectional (up/down capability)
• Timing Architecture: Synchronous operation with positive edge triggering
• Electrical Specifications: Supply voltage range 4.5 V ~ 5.5 V
• Package Compatibility: 16-SOIC surface mount form factor with identical pin pitch (0.154", 3.90mm width)
• Series Compatibility: 74HCT logic family

The CD74HCT191M qualifies as a manufacturer-recommended substitute based on matching all functional and mechanical parameters within the 74HCT series.

Parameter Comparison

Engineering Selection Recommendations

Both the 74HCT191D,652 and CD74HCT191M are classified as obsolete products. Selection between these parts should be based on the following criteria:

74HCT191D,652 (NXP): Offers a maximum count rate of 39 MHz and operates across the temperature range -40°C to 125°C. This part carries RoHS3 compliance certification.

CD74HCT191M (Harris): Provides a maximum count rate of 30 MHz with an extended lower temperature operating limit of -55°C. This part is RoHS non-compliant.

For applications requiring the highest count rate performance within standard industrial temperature ranges, the NXP variant is suitable. For applications requiring extended low-temperature operation, the Harris variant accommodates -55°C minimum operation. Both parts share identical package geometry and electrical supply specifications, ensuring direct pin-for-pin compatibility in 16-SOIC surface mount designs.

Frequently Asked Questions (FAQ)

Q: Can the CD74HCT191M replace the 74HCT191D,652 in existing designs?

A: Yes. Both parts are 4-bit binary counters within the 74HCT series, share identical 16-SOIC package dimensions, and operate at the same supply voltage range (4.5 V ~ 5.5 V). Pin-for-pin compatibility is maintained.

Q: What is the significance of the 39 MHz versus 30 MHz count rate difference?

A: The 74HCT191D,652 supports a maximum count rate of 39 MHz, while the CD74HCT191M supports 30 MHz. Applications requiring counting frequencies above 30 MHz must use the NXP part.

Q: Are there temperature range considerations for substitution?

A: The CD74HCT191M operates at -55°C minimum, extending 15°C lower than the 74HCT191D,652 (-40°C minimum). For applications requiring operation below -40°C, the Harris part is required.

Q: What is the impact of RoHS compliance differences?

A: The 74HCT191D,652 is RoHS3 compliant, while the CD74HCT191M is RoHS non-compliant. Regulatory requirements for the end application determine which part is acceptable.

Q: Are both parts available in the same packaging format?

A: Yes. Both the 74HCT191D,652 and CD74HCT191M are supplied in 16-SOIC surface mount packages with identical 0.154" (3.90mm) width specifications, ensuring mechanical compatibility on PCB layouts.