74VHC221ASJ Equivalent & Substitute Parts

Part Overview

The 74VHC221ASJ is a monostable multivibrator logic IC manufactured by onsemi, featuring dual independent circuits with Schmitt trigger inputs and 8.1 ns propagation delay. This component is classified as obsolete, making substitute parts necessary for new designs and ongoing production requirements. The 16-SOIC surface mount package and 2V to 5.5V supply voltage range define its operational envelope. Identifying compatible alternatives ensures design continuity and supply chain flexibility.

Substiute Parts

74VHC221ASJ

onsemiIn Stock: 91474VHC221ASJ Datasheet

Current PartRFQ

SN74LV221ANSR

Texas InstrumentsIn Stock: 954SN74LV221ANSR Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 74VHC221ASJ is determined by the following critical parameters:

• Logic Function: Dual monostable multivibrator with independent circuits
• Schmitt Trigger Input: Required feature for noise immunity
• Supply Voltage Range: 2 V ~ 5.5 V compatibility
• Operating Temperature Range: -40°C ~ 85°C
• Package Type: 16-SOIC surface mount configuration
• Pin Count: 16 pins

The SN74LV221ANSR from Texas Instruments satisfies all substitution criteria. Both devices share identical supply voltage specifications, operating temperature ranges, package dimensions, and functional architecture. The 74LV series represents an active product line, providing long-term availability compared to the obsolete 74VHC series.

Parameter Comparison

Engineering Selection Recommendations

The SN74LV221ANSR is the qualified substitute for the 74VHC221ASJ based on the following factors:

Functional Compatibility: Both devices implement identical dual monostable multivibrator architecture with Schmitt trigger inputs, ensuring pin-for-pin functional equivalence in circuit applications.

Electrical Specifications: Supply voltage range (2 V ~ 5.5 V) and operating temperature range (-40°C ~ 85°C) are identical. Output current specifications for the SN74LV221ANSR (12 mA) exceed those of the 74VHC221ASJ (8 mA), providing improved drive capability without circuit modification requirements.

Package Compatibility: Both components use 16-SOIC surface mount packaging with identical physical dimensions, enabling direct PCB layout compatibility.

Product Status and Compliance: The SN74LV221ANSR maintains active product status with ROHS3 compliance certification, ensuring long-term availability and regulatory alignment. The 74VHC221ASJ obsolete status necessitates transition to active alternatives.

Propagation Delay Consideration: The SN74LV221ANSR exhibits 13.2 ns propagation delay compared to 8.1 ns for the 74VHC221ASJ. This 5.1 ns difference must be evaluated within specific circuit timing requirements to confirm suitability for time-critical applications.

Frequently Asked Questions (FAQ)

Q: Can the SN74LV221ANSR directly replace the 74VHC221ASJ without circuit modifications?

A: Yes, for most applications. Both devices share identical pin configurations, supply voltage ranges, and operating temperature specifications. The increased propagation delay (13.2 ns vs. 8.1 ns) and higher output current (12 mA vs. 8 mA) are generally compatible with existing designs. Verify timing requirements in applications where the 5.1 ns delay difference impacts circuit performance.

Q: What is the significance of the propagation delay difference?

A: Propagation delay determines the time interval between input signal transition and output response. The SN74LV221ANSR's 13.2 ns delay is 5.1 ns longer than the 74VHC221ASJ. In timing-sensitive applications, this difference may require circuit analysis to confirm acceptable performance margins.

Q: Are there packaging considerations for this substitution?

A: No. Both components use identical 16-SOIC surface mount packages with 0.209" width and 5.30mm dimensions. PCB layouts, solder reflow profiles, and assembly processes require no modification.

Q: Why is the 74VHC221ASJ classified as obsolete?

A: Obsolete status indicates the manufacturer has discontinued production. The SN74LV221ANSR from Texas Instruments represents an active alternative within the 74LV logic family, ensuring continued availability for new designs and production requirements.

Q: Does the higher output current of the SN74LV221ANSR affect circuit design?

A: The SN74LV221ANSR provides 12 mA output current compared to 8 mA for the 74VHC221ASJ. This increased capability improves load-driving performance and reduces output impedance, generally benefiting circuit operation without requiring design changes.

Q: What compliance certifications apply to the substitute part?

A: The SN74LV221ANSR holds ROHS3 compliance certification and REACH unaffected status, meeting current regulatory requirements for electronic component manufacturing and distribution.