CD74HCT221M Equivalent & Substitute Parts

Part Overview

The CD74HCT221M is a monostable multivibrator logic integrated circuit manufactured by Texas Instruments, housed in a 16-SOIC surface mount package. This component is discontinued at DiGi Electronics, necessitating identification of functionally equivalent alternatives for ongoing design requirements and production needs. The part operates as a dual independent monostable multivibrator with Schmitt trigger inputs, suitable for timing and pulse generation applications in digital logic circuits.

Substiute Parts

CD74HCT221M

Texas InstrumentsIn Stock: 1654CD74HCT221M Datasheet

Current PartRFQ

CD74HCT221M96

Texas InstrumentsIn Stock: 4840CD74HCT221M96 Datasheet

DirectRFQ

74HCT00PW,118

NXP SemiconductorsIn Stock: 1484474HCT00PW,118 Datasheet

MFR RecommendedRFQ

74HCT221D,118

Nexperia USA Inc.In Stock: 346274HCT221D,118 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the CD74HCT221M is determined by the following critical parameters:

• Logic Function: Dual monostable multivibrator configuration with 2 independent circuits
• Package Compatibility: 16-SOIC surface mount package (0.154", 3.90mm width)
• Electrical Specifications: Supply voltage 4.5 V ~ 5.5 V, output current 4 mA / 4 mA, Schmitt trigger input capability
• Timing Performance: Propagation delay characteristics
• Temperature Range: Operating temperature specifications
• Compliance: RoHS3 compliance and MSL rating

Substitute parts are grouped into two categories: direct manufacturer equivalents from Texas Instruments with identical specifications, and functionally compatible alternatives from other manufacturers meeting the same electrical and mechanical requirements.

Parameter Comparison

Engineering Selection Recommendations

CD74HCT221M96 (Texas Instruments): This part provides identical electrical and timing specifications to the original CD74HCT221M, with the same 18 ns propagation delay and full temperature range (-55°C ~ 125°C). Although marked as obsolete, it maintains complete functional equivalence. Packaging differs in format (Cut Tape & Digi-Reel® versus Tube), which may affect procurement and assembly processes.

74HCT221D,118 (Nexperia USA Inc.): This substitute maintains functional compatibility across all critical parameters including dual monostable configuration, Schmitt trigger inputs, and identical supply voltage and output current specifications. The primary difference is propagation delay of 31 ns versus 18 ns, and a reduced operating temperature range (-40°C ~ 125°C versus -55°C ~ 125°C). This part carries active product status, ensuring ongoing availability. The 16-SOIC package and surface mount configuration remain identical. Selection of this part requires confirmation that the 31 ns propagation delay is acceptable for the application timing requirements and that the -40°C minimum operating temperature meets environmental specifications.

All substitute parts maintain RoHS3 compliance and MSL rating of 1 (Unlimited), ensuring compatibility with standard manufacturing and storage protocols.

Frequently Asked Questions (FAQ)

Q: Can CD74HCT221M96 be used as a direct replacement for CD74HCT221M?

A: Yes. CD74HCT221M96 provides identical electrical specifications, including 18 ns propagation delay, dual independent monostable circuits, and full temperature range operation (-55°C ~ 125°C). The primary difference is packaging format (Cut Tape & Digi-Reel® versus Tube). Both parts are manufactured by Texas Instruments and are functionally equivalent.

Q: What is the key difference between CD74HCT221M and 74HCT221D,118?

A: The 74HCT221D,118 has a propagation delay of 31 ns compared to 18 ns for the CD74HCT221M. Additionally, the operating temperature range is -40°C ~ 125°C versus -55°C ~ 125°C. All other electrical parameters, including supply voltage, output current, and package configuration, remain identical. Substitution is valid only if the application can tolerate the longer propagation delay and higher minimum operating temperature.

Q: Are all substitute parts in the same package?

A: Yes. All listed substitute parts use the 16-SOIC (0.154", 3.90mm width) surface mount package, ensuring mechanical and electrical compatibility with existing PCB designs. Packaging format (Tube, Cut Tape & Digi-Reel®, or Tape & Reel) differs only in how the components are supplied and does not affect circuit performance.

Q: Do substitute parts meet the same compliance standards?

A: Yes. All substitute parts listed are ROHS3 compliant with MSL rating of 1 (Unlimited), matching the original CD74HCT221M specifications. This ensures compatibility with standard manufacturing processes and storage requirements.

Q: Which substitute part should be selected for new designs?

A: The 74HCT221D,118 from Nexperia USA Inc. is recommended for new designs due to its active product status, ensuring long-term availability. This part is suitable provided the 31 ns propagation delay and -40°C minimum operating temperature are acceptable for the application requirements.