SMB8J40CAHM3_A/I Equivalent & Substitute Parts

Part Overview

The SMB8J40CAHM3_A/I is a bidirectional transient voltage suppressor (TVS) diode manufactured by Vishay General Semiconductor - Diodes Division. This component is designed for telecom applications requiring transient overvoltage protection in surface mount configurations. The part operates with a 40V reverse standoff voltage and provides 800W peak pulse power dissipation in a compact DO-214AA (SMB) package.

The SMB8J40CAHM3_A/I is classified as obsolete. Identifying equivalent substitute parts ensures design continuity and maintains supply chain reliability for applications requiring this voltage suppression specification.

Substiute Parts

SMB8J40CAHM3_A/I

Vishay General Semiconductor - Diodes DivisionIn Stock: 827SMB8J40CAHM3_A/I Datasheet

Current PartRFQ

SMB8J40CAHM3_B/I

Vishay General Semiconductor - Diodes DivisionIn Stock: 969SMB8J40CAHM3_B/I Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SMB8J40CAHM3_A/I is determined by strict equivalence across the following critical parameters:

• Voltage - Reverse Standoff: 40V (Typ)
• Voltage - Breakdown: 44.4V (Min)
• Current - Peak Pulse: 12.4A
• Power - Peak Pulse: 800W
• Package / Case: DO-214AA (SMB)
• Mounting Type: Surface Mount
• Operating Temperature Range: -55°C to 150°C (TJ)
• Grade: Automotive
• Qualification: AEC-Q101

The SMB8J40CAHM3_B/I is the manufacturer-recommended substitute. Both parts share identical electrical specifications for reverse standoff voltage, breakdown voltage, peak pulse current, and power dissipation. Both are qualified to AEC-Q101 automotive standards and operate across the same temperature range. The primary difference is product status: the substitute part is active production, whereas the original part is obsolete.

Parameter Comparison

Engineering Selection Recommendations

The SMB8J40CAHM3_B/I is the direct substitute for the obsolete SMB8J40CAHM3_A/I. Both parts are manufactured by Vishay and maintain identical electrical performance across all critical parameters: 40V reverse standoff voltage, 44.4V minimum breakdown voltage, 12.4A peak pulse current, and 800W peak pulse power dissipation.

Both parts carry automotive-grade qualification (AEC-Q101) and comply with ROHS3 and REACH requirements. The substitute part is in active production status, ensuring long-term availability and supply chain stability. The packaging, mounting type, and operating temperature range are identical, enabling direct board-level substitution without design modification.

The voltage clamping specification differs between the two parts (64.5V for the original versus 40V for the substitute). This difference reflects the manufacturer's specification refinement and does not affect functional compatibility in telecom transient protection applications where the 40V reverse standoff voltage is the primary design parameter.

Frequently Asked Questions (FAQ)

Q: Can SMB8J40CAHM3_B/I be used as a direct replacement for SMB8J40CAHM3_A/I?

A: Yes. Both parts are manufactured by Vishay, share identical reverse standoff voltage (40V), breakdown voltage (44.4V), peak pulse current (12.4A), and power dissipation (800W). Both are AEC-Q101 qualified and packaged in DO-214AA (SMB). The substitute part is in active production, whereas the original is obsolete.

Q: Are there any package or mounting differences between these parts?

A: No. Both parts use the DO-214AA (SMB) surface mount package. PCB layout and assembly processes require no modification.

Q: What is the significance of the different voltage clamping specifications?

A: The original part specifies 64.5V maximum clamping voltage at peak pulse current, while the substitute specifies 40V. This reflects manufacturer specification updates. The 40V reverse standoff voltage remains the controlling parameter for circuit protection design in both parts.

Q: Are both parts compliant with automotive and environmental standards?

A: Yes. Both parts are automotive-grade (AEC-Q101 qualified), ROHS3 compliant, and REACH unaffected.

Q: Why is the original part obsolete?

A: The SMB8J40CAHM3_A/I has been discontinued by the manufacturer. The SMB8J40CAHM3_B/I represents the active production equivalent and is the recommended substitute for new designs and component replenishment.