CD74HC4538M Equivalent & Substitute Parts

Part Overview

The CD74HC4538M is a monostable multivibrator logic IC manufactured by Texas Instruments in a 16-SOIC surface mount package. This device features dual independent circuits with Schmitt trigger inputs, a 21 ns propagation delay, and operates across a 2 V to 6 V supply voltage range with an extended temperature range of -55°C to 125°C. The part is currently in Last Time Buy status, making equivalent and substitute parts necessary for ongoing design support and procurement planning.

Substiute Parts

CD74HC4538M

Texas InstrumentsIn Stock: 1791CD74HC4538M Datasheet

Current PartRFQ

CD74HC4538M96

Texas InstrumentsIn Stock: 18296CD74HC4538M96 Datasheet

MFR RecommendedRFQ

74HC4538D,653

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

MFR RecommendedRFQ

74HC4538D-Q100,118

Nexperia USA Inc.In Stock: 349774HC4538D-Q100,118 Datasheet

MFR RecommendedRFQ

MC74HC4538ADG

onsemiIn Stock: 1226MC74HC4538ADG Datasheet

MFR RecommendedRFQ

MC74HC4538ADR2G

onsemiIn Stock: 15678MC74HC4538ADR2G Datasheet

MFR RecommendedRFQ

NLV74HC4538ADR2G

onsemiIn Stock: 3807NLV74HC4538ADR2G Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the CD74HC4538M is determined by the following critical parameters:

• Base product number (74HC4538 family)
• Package type (16-SOIC surface mount)
• Supply voltage range (2 V ~ 6 V)
• Output current capability (5.2 mA minimum)
• Mounting type (Surface Mount)
• Compliance certifications (ROHS3, REACH Unaffected)

Substitute parts are grouped into two categories based on propagation delay and Schmitt trigger input availability:

Category A (Direct Equivalents): Parts with 21 ns propagation delay and Schmitt trigger inputs, maintaining identical timing and input characteristics to the CD74HC4538M.

Category B (Functional Alternatives): Parts with 25 ns or 30 ns propagation delay, with or without Schmitt trigger inputs. These parts maintain functional compatibility within the 74HC4538 family but with timing variations that may affect circuit performance in delay-sensitive applications.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitute (Recommended for Direct Replacement):

CD74HC4538M96 is the optimal substitute for the CD74HC4538M. Both parts are manufactured by Texas Instruments, share identical electrical specifications including 21 ns propagation delay and Schmitt trigger inputs, and maintain the same operating temperature range (-55°C to 125°C). The primary difference is packaging format: CD74HC4538M96 is supplied in Cut Tape and Digi-Reel format rather than Tube, with significantly higher inventory availability (18,213 pcs vs. 1,699 pcs). Both parts are ROHS3 compliant and carry Active product status.

Secondary Substitutes (Functional Alternatives with Timing Variations):

MC74HC4538ADR2G (onsemi) provides an Active status alternative with Schmitt trigger input preservation but introduces a 30 ns propagation delay (9 ns slower than the original). This part maintains the -55°C to 125°C temperature range and is available in Cut Tape & Digi-Reel packaging with 15,592 pcs in stock.

74HC4538D,653 and 74HC4538D-Q100,118 (Nexperia USA Inc.) are Active status alternatives with 25 ns propagation delay (4 ns slower) but lack Schmitt trigger inputs. These parts operate across -40°C to 125°C and are suitable for applications where input hysteresis is not critical. The automotive-qualified variant (74HC4538D-Q100,118) carries AEC-Q100 certification.

Parts to Avoid:

MC74HC4538ADG and NLV74HC4538ADR2G carry Obsolete product status and should not be selected for new designs or long-term procurement.

Frequently Asked Questions (FAQ)

Q: Can CD74HC4538M96 be used as a direct replacement for CD74HC4538M?

A: Yes. CD74HC4538M96 is electrically and functionally identical to CD74HC4538M. Both are Texas Instruments products with 21 ns propagation delay, Schmitt trigger inputs, and -55°C to 125°C operating range. The only difference is packaging format (Cut Tape & Digi-Reel vs. Tube).

Q: What is the impact of using a 25 ns or 30 ns propagation delay substitute?

A: Propagation delay directly affects circuit timing. A 4 ns increase (74HC4538D series) or 9 ns increase (MC74HC4538ADR2G) will extend the output pulse width by the same amount. Applications with strict timing requirements must account for this variation. Non-critical timing applications may tolerate these delays.

Q: Why do some substitutes lack Schmitt trigger inputs?

A: Schmitt trigger inputs provide hysteresis, improving noise immunity on slow-rising input signals. The Nexperia 74HC4538D series omits this feature, reducing component complexity and cost. Applications with clean, fast-rising input signals may not require Schmitt trigger functionality.

Q: Are all substitutes compatible with the same PCB footprint?

A: Yes. All listed substitutes use the 16-SOIC (0.154", 3.90mm Width) package, ensuring identical PCB footprint compatibility. Surface mount assembly equipment settings remain unchanged.

Q: What is the difference between Cut Tape, Digi-Reel, and Tape & Reel packaging?

A: These are supply format variations for the same component. Cut Tape and Digi-Reel are suitable for automated pick-and-place assembly. Tape & Reel is optimized for high-volume production. All formats contain the same die and are electrically identical.

Q: Is the automotive-qualified variant (74HC4538D-Q100,118) suitable for non-automotive applications?

A: Yes. AEC-Q100 qualification exceeds standard industrial requirements and provides additional reliability assurance. This part is suitable for any application requiring the 74HC4538 function.

Q: Why is CD74HC4538M in Last Time Buy status?

A: Last Time Buy status indicates Texas Instruments is discontinuing this specific packaging variant. CD74HC4538M96 (Cut Tape & Digi-Reel format) remains Active and is the recommended migration path for ongoing procurement.