SA45A-E3/73 Equivalent & Substitute Parts

Part Overview

The SA45A-E3/73 is a unidirectional Transient Voltage Suppressor (TVS) diode manufactured by Vishay General Semiconductor - Diodes Division. This through-hole component operates with a 45V reverse standoff voltage and provides 72.7V maximum clamping voltage at peak pulse current. The device is designed for general-purpose transient voltage suppression applications and is currently in active product status with RoHS3 compliance. Substitute parts become necessary when the primary component experiences supply constraints, obsolescence, or when alternative manufacturers' inventory availability improves procurement timelines.

Substiute Parts

SA45A-E3/73

Vishay General Semiconductor - Diodes DivisionIn Stock: 32427SA45A-E3/73 Datasheet

Current PartRFQ

SA45A

Fairchild SemiconductorIn Stock: 10501SA45A Datasheet

MFR RecommendedRFQ

SAC45

Littelfuse Inc.In Stock: 4625SAC45 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SA45A-E3/73 is determined by strict equivalence across the following critical parameters:

• Voltage - Reverse Standoff: 45V (nominal)
• Voltage - Breakdown (Min): 50V
• Voltage - Clamping (Max) @ Ipp: within acceptable tolerance range
• Current - Peak Pulse (10/1000µs): minimum 6.8A
• Power - Peak Pulse: 500W
• Package / Case: DO-204AC (DO-15) axial through-hole
• Type: Zener diode, unidirectional configuration
• Operating Temperature Range: -55°C to 175°C (TJ)

Substitute parts must maintain identical mounting type, package footprint, and electrical performance envelope to ensure direct circuit board compatibility without design modification.

Parameter Comparison

Engineering Selection Recommendations

The SA45A-E3/73 remains the primary component choice due to its active product status and confirmed availability of 32,400 units in stock. Both substitute parts maintain full electrical and mechanical compatibility within the specified parameter envelope.

The SA45A from Fairchild Semiconductor provides direct electrical equivalence with 7A peak pulse current capability. However, this part carries obsolete product status, indicating discontinued manufacturing and potential long-term supply uncertainty.

The SAC45 from Littelfuse Inc. is actively manufactured and maintains all critical electrical parameters. The clamping voltage specification of 77V (versus 72.7V) represents a 4.3V increase, which remains within acceptable tolerance for general-purpose transient suppression applications. This part is available in Cut Tape (CT) packaging format.

Selection between substitute parts should prioritize active product status and current inventory availability. Both SA45A-E3/73 and SAC45 meet these criteria and are suitable for direct substitution in circuit applications.

Frequently Asked Questions (FAQ)

Q: Can SA45A from Fairchild Semiconductor be used as a direct replacement for SA45A-E3/73?

A: Yes, the SA45A provides electrical and mechanical equivalence. However, the Fairchild part carries obsolete status, which may limit future availability and support.

Q: What is the significance of the 77V clamping voltage on the SAC45 compared to the 72.7V specification of the main part?

A: The SAC45 clamping voltage of 77V is within acceptable tolerance for general-purpose TVS applications. Both parts maintain the same 45V reverse standoff and 50V minimum breakdown voltage, ensuring circuit protection performance remains equivalent.

Q: Are all three parts compatible with the same PCB footprint?

A: Yes. All three parts use the DO-204AC (DO-15) axial through-hole package, ensuring identical mounting compatibility without PCB redesign.

Q: What compliance certifications apply to these substitute parts?

A: All three parts are RoHS3 compliant and carry EAR99 export classification. The main part and SAC45 are REACH unaffected.

Q: Does packaging format affect substitution eligibility?

A: Packaging format (Bulk, Cut Tape) affects procurement and handling but does not impact electrical or mechanical substitution compatibility. Component performance remains identical regardless of supply packaging.

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

A: The SAC45 from Littelfuse Inc. is recommended for new designs due to active product status and current manufacturing support, ensuring long-term component availability.