74HC4538N,652 Equivalent & Substitute Parts

Part Overview

The 74HC4538N,652 is a monostable multivibrator logic integrated circuit manufactured by NXP USA Inc. in a 16-DIP through-hole package. This device features two independent circuits with a 25 ns propagation delay and operates across a 2 V to 6 V supply voltage range. The part is classified as obsolete, making equivalent and substitute parts necessary for ongoing system maintenance, repairs, and legacy design support.

Substiute Parts

74HC4538N,652

NXP USA Inc.In Stock: 124174HC4538N,652 Datasheet

Current PartRFQ

CD74HC4538E

Harris CorporationIn Stock: 2188CD74HC4538E Datasheet

DirectRFQ

74HC4538D,653

Nexperia USA Inc.In Stock: 230374HC4538D,653 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the 74HC4538N,652 is determined by the following critical parameters:

• Base product number (74HC4538) ensures functional equivalence
• Logic type (monostable multivibrator) and independent circuits (2) must remain constant
• Voltage supply range (2 V ~ 6 V) and output current specifications (5.2 mA) must be maintained
• Propagation delay tolerance (25 ns specification) allows for minor variations
• Package compatibility depends on mounting requirements: through-hole packages (16-DIP, 16-PDIP) are directly compatible; surface-mount packages (16-SO) require PCB redesign

Two substitute parts are identified:

1. CD74HC4538E (Harris Corporation) - Direct functional equivalent with through-hole packaging
2. 74HC4538D,653 (Nexperia USA Inc.) - Manufacturer-recommended substitute with surface-mount packaging

Parameter Comparison

Engineering Selection Recommendations

For through-hole PCB designs requiring direct socket compatibility with the original 74HC4538N,652, the CD74HC4538E provides functional equivalence in the same 16-DIP package. This substitute operates across an extended temperature range (-55°C to 125°C) and includes Schmitt trigger input capability. However, the CD74HC4538E carries RoHS non-compliant status, which may conflict with regulatory requirements in new designs or procurement policies.

The 74HC4538D,653 is the manufacturer-recommended substitute and is currently in active production status. This part maintains full electrical compatibility with identical propagation delay (25 ns), voltage supply range, and output current specifications. The 74HC4538D,653 is ROHS3 compliant and carries REACH unaffected status, meeting modern environmental and regulatory standards. The primary consideration is packaging: the 16-SOIC surface-mount package requires PCB redesign compared to the through-hole 16-DIP format of the original part.

Selection between these substitutes depends on PCB form factor constraints and regulatory compliance requirements. For legacy through-hole designs where RoHS compliance is not mandated, CD74HC4538E is suitable. For new designs or systems requiring modern compliance certifications, 74HC4538D,653 is the appropriate choice despite requiring surface-mount assembly.

Frequently Asked Questions (FAQ)

Q: Can the CD74HC4538E be used as a direct replacement for the 74HC4538N,652 in existing designs?

A: Yes, the CD74HC4538E is functionally equivalent and shares the same 16-DIP through-hole package footprint. Both parts operate at identical voltage supply ranges (2 V ~ 6 V) and output current levels (5.2 mA). The CD74HC4538E's faster propagation delay (21 ns versus 25 ns) and extended temperature range (-55°C to 125°C) provide enhanced performance margins. The primary consideration is RoHS compliance status; the CD74HC4538E is non-compliant, which may affect procurement eligibility depending on organizational standards.

Q: Why is the 74HC4538D,653 recommended as a manufacturer substitute if it uses a different package?

A: The 74HC4538D,653 is the active production equivalent from Nexperia USA Inc., the successor entity to NXP's logic product line. It maintains identical electrical specifications (25 ns propagation delay, 2 V ~ 6 V supply, 5.2 mA output current) and is ROHS3 compliant with REACH unaffected status. The 16-SOIC surface-mount package represents modern manufacturing standards. While PCB redesign is required, this substitute ensures long-term availability and compliance with current regulatory frameworks.

Q: Are there any functional differences between the three parts that affect circuit behavior?

A: The CD74HC4538E includes Schmitt trigger input capability, while both the 74HC4538N,652 and 74HC4538D,653 do not. This feature provides improved noise immunity on input signals but does not affect core monostable multivibrator operation. The CD74HC4538E's 21 ns propagation delay is faster than the specified 25 ns of the main part and its substitute, resulting in shorter output pulse widths for identical timing component values. This difference is within typical design tolerances but should be verified in timing-critical applications.

Q: What are the package compatibility considerations when selecting a substitute?

A: The 74HC4538N,652 and CD74HC4538E both use 16-DIP through-hole packages with identical 0.300" (7.62mm) spacing, allowing direct socket substitution without PCB modification. The 74HC4538D,653 uses a 16-SOIC surface-mount package with 0.154" (3.90mm) width, requiring PCB layout redesign and surface-mount assembly processes. Through-hole substitution is appropriate for repair and maintenance of legacy systems; surface-mount substitution is suitable for new production designs where manufacturing processes support SMD assembly.

Q: Does the extended operating temperature range of the CD74HC4538E provide advantages?

A: The CD74HC4538E operates from -55°C to 125°C compared to -40°C to 125°C for both the 74HC4538N,652 and 74HC4538D,653. This extended lower temperature limit provides additional margin for applications in cold environments or equipment with wide operating temperature specifications. However, this advantage is only relevant if the system design requires operation below -40°C; standard industrial and commercial applications typically do not benefit from this extended range.