SMA4F36AY Equivalent & Substitute Parts

Part Overview

The SMA4F36AY is a unidirectional transient voltage suppressor (TVS) diode manufactured by STMicroelectronics, designed for surface mount applications in automotive-grade circuits. This component operates with a 36V reverse standoff voltage and provides 76V maximum clamping voltage at peak pulse current. The SMA4F36AY is classified as obsolete, necessitating identification of active substitute components that maintain electrical and mechanical compatibility for new designs and production continuity.

Substiute Parts

SMA4F36AY

STMicroelectronicsIn Stock: 10715SMA4F36AY Datasheet

Current PartRFQ

SM4T47AY

STMicroelectronicsIn Stock: 4476SM4T47AY Datasheet

MFR RecommendedRFQ

SM4T39AY

STMicroelectronicsIn Stock: 4543SM4T39AY Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SMA4F36AY is determined by the following critical electrical and mechanical parameters:

Electrical Compatibility Criteria:

• Unidirectional channel configuration (1 channel required)
• Reverse standoff voltage range compatible with 36V nominal operation
• Clamping voltage performance within acceptable circuit protection limits
• Peak pulse current rating sufficient for transient suppression
• Peak pulse power rating of 400W
• Operating temperature range supporting -55°C to 150°C minimum

Mechanical Compatibility Criteria:

• Surface mount packaging (SMA or SMAflat form factors)
• Automotive-grade classification
• AEC-Q101 qualification
• Moisture sensitivity level 1 (Unlimited)

Substitute Parts Identified:

1. SM4T47AY (MFR Recommended): Active status, 40V standoff, 84V clamping, 27A peak pulse, DO-214AC SMA package
2. SM4T39AY (Similar): Active status, 33V standoff, 69.7V clamping, 33A peak pulse, DO-214AC SMA package

Both substitute parts maintain automotive-grade certification, AEC-Q101 qualification, and surface mount configuration. The SM4T47AY represents the manufacturer-recommended replacement with higher voltage ratings, while SM4T39AY provides lower voltage operation with increased current capacity.

Parameter Comparison

Engineering Selection Recommendations

SM4T47AY Selection Rationale:

The SM4T47AY is the manufacturer-recommended substitute for the obsolete SMA4F36AY. This part maintains full automotive-grade certification and AEC-Q101 qualification. The higher reverse standoff voltage (40V vs. 36V) and clamping voltage (84V vs. 76V) provide enhanced transient suppression capability. Peak pulse current is reduced to 27A from 30A, which remains adequate for most circuit protection applications. The operating temperature range extends to 150°C, which covers standard automotive thermal requirements. The DO-214AC SMA package provides direct mechanical compatibility with standard surface mount assembly processes.

SM4T39AY Selection Rationale:

The SM4T39AY offers an alternative for applications requiring lower voltage operation. The 33V reverse standoff voltage and 69.7V clamping voltage suit circuits with reduced transient voltage exposure. This part delivers increased peak pulse current capacity at 33A, providing superior current handling for high-energy transient events. Active product status and full automotive qualification ensure long-term availability and supply chain stability. The DO-214AC SMA package maintains surface mount compatibility.

Compliance Considerations:

Both substitute parts maintain ROHS3 compliance and REACH unaffected status, ensuring regulatory alignment with current environmental standards. Automotive-grade classification and AEC-Q101 qualification confirm suitability for automotive circuit protection applications.

Frequently Asked Questions (FAQ)

Q: Can SM4T47AY directly replace SMA4F36AY in existing designs?

A: SM4T47AY provides electrical substitution with higher voltage ratings (40V standoff, 84V clamping). The DO-214AC SMA package differs from the SMA4F36AY's DO-221AC SMAflat package. Physical board layout verification is required to confirm mechanical fit. Both parts are surface mount with identical lead spacing for standard SMA packages.

Q: What is the difference between SM4T47AY and SM4T39AY?

A: SM4T47AY operates at higher voltage levels (40V standoff, 84V clamping) with 27A peak pulse current. SM4T39AY operates at lower voltage levels (33V standoff, 69.7V clamping) with 33A peak pulse current. Selection depends on the circuit's transient voltage profile and current handling requirements.

Q: Are both substitute parts automotive-qualified?

A: Yes. Both SM4T47AY and SM4T39AY carry automotive-grade classification and AEC-Q101 qualification, matching the original SMA4F36AY specification.

Q: What is the operating temperature difference between the main part and substitutes?

A: The SMA4F36AY operates from -55°C to 175°C. Both substitute parts operate from -55°C to 150°C. For applications requiring operation above 150°C, the SMA4F36AY's extended temperature range may be necessary, though this part is obsolete.

Q: Do the substitute parts have the same moisture sensitivity level?

A: Yes. All three parts (SMA4F36AY, SM4T47AY, and SM4T39AY) have MSL 1 (Unlimited), indicating no moisture sensitivity restrictions for storage and handling.

Q: What packaging differences exist between these parts?

A: The SMA4F36AY uses DO-221AC with SMA Flat Leads. Both substitute parts use DO-214AC with standard SMA leads. While both are surface mount SMA packages, the flat lead variant differs mechanically. PCB footprint compatibility must be verified during design transition.

Q: Are there supply chain advantages to using the substitute parts?

A: Yes. Both SM4T47AY and SM4T39AY have active product status with current inventory availability (4446 and 4485 units respectively), compared to the obsolete SMA4F36AY. Active status ensures long-term supply continuity and manufacturing support.