AS3PK-M3/86A Equivalent & Substitute Parts

Part Overview

The AS3PK-M3/86A is an avalanche diode manufactured by Vishay General Semiconductor - Diodes Division, operating at 800V with a 2.1A average rectified current rating. This component belongs to the eSMP® series and is designed for surface mount applications in the TO-277A (SMPC) package. The device is Active in product status and fully RoHS3 compliant with unlimited moisture sensitivity level (MSL 1).

Equivalent and substitute parts are identified when alternative components meet or exceed the electrical and mechanical specifications of the primary device, enabling design flexibility, inventory optimization, and supply chain continuity.

Substiute Parts

AS3PK-M3/86A

Vishay General Semiconductor - Diodes DivisionIn Stock: 970AS3PK-M3/86A Datasheet

Current PartRFQ

STTH208U

STMicroelectronicsIn Stock: 20394STTH208U Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AS3PK-M3/86A is determined by the following critical electrical and mechanical parameters:

Voltage Rating: The substitute must maintain a DC reverse voltage (Vr) rating of 800V or higher to ensure equivalent or superior reverse bias protection.

Current Rating: The substitute must support an average rectified current (Io) of 2.1A or greater to handle the same or higher load conditions.

Forward Voltage Characteristics: Forward voltage drop (Vf) at specified current levels must be compatible with circuit design requirements.

Recovery Characteristics: Reverse recovery time (trr) and recovery speed classification determine switching performance and must be suitable for the application.

Reverse Leakage Current: Leakage at rated reverse voltage must not exceed specified limits to maintain circuit integrity.

Temperature Range: Operating junction temperature range must encompass the application environment.

Package Compatibility: Surface mount packages must be mechanically compatible with PCB layout and assembly processes.

Compliance: RoHS3 compliance and REACH status must match or exceed the primary component.

The STTH208U from STMicroelectronics meets these substitution criteria with equivalent voltage and current ratings, active product status, and matching compliance certifications.

Parameter Comparison

Engineering Selection Recommendations

Electrical Compatibility: Both the AS3PK-M3/86A and STTH208U operate at 800V reverse voltage with comparable current ratings. The STTH208U is rated at 2.0A average rectified current, which is 0.1A lower than the primary component. This difference is acceptable for applications where the design margin permits operation at the substitute's rated current.

Recovery Performance: The STTH208U exhibits significantly faster reverse recovery time (75 ns versus 1.2 µs), indicating fast recovery technology compared to the standard recovery classification of the AS3PK-M3/86A. This characteristic may provide improved switching efficiency in high-frequency applications.

Leakage Characteristics: The STTH208U demonstrates lower reverse leakage current (5 µA versus 10 µA at 800V), which may reduce power dissipation in standby conditions.

Package Consideration: The AS3PK-M3/86A uses TO-277 (3-PowerDFN) packaging, while the STTH208U uses DO-214AA (SMB) packaging. These are distinct surface mount packages with different footprints and thermal characteristics. PCB layout redesign is required for package substitution.

Compliance Status: Both components are RoHS3 compliant, REACH unaffected, and classified under ECCN EAR99. Both maintain MSL 1 (unlimited) moisture sensitivity level, ensuring equivalent handling and storage requirements.

Product Status: Both components are Active in product status with established supply chains and manufacturing continuity.

Frequently Asked Questions (FAQ)

Q: Can the STTH208U directly replace the AS3PK-M3/86A without PCB modification?

A: No. While both are surface mount rectifier diodes with equivalent voltage ratings, they use different packages (TO-277 versus SMB). Direct footprint substitution is not possible. PCB layout redesign is required to accommodate the different package geometry and pin configuration.

Q: Is the 0.1A lower current rating of the STTH208U acceptable?

A: Acceptability depends on circuit design margins. If the application operates at or near the 2.1A rating of the AS3PK-M3/86A, the STTH208U's 2.0A rating may be insufficient. If the design includes margin below 2.0A, the substitute is suitable.

Q: What is the significance of the faster recovery time in the STTH208U?

A: The STTH208U's 75 ns recovery time (fast recovery) versus the AS3PK-M3/86A's 1.2 µs (standard recovery) indicates different switching characteristics. Fast recovery diodes reduce reverse recovery losses and are beneficial in high-frequency switching applications. Standard recovery diodes are suitable for lower-frequency rectification.

Q: Are thermal characteristics equivalent between these packages?

A: No. The TO-277 (3-PowerDFN) and SMB (DO-214AA) packages have different thermal dissipation characteristics. Thermal analysis specific to the substitute package is required to ensure adequate heat management in the target application.

Q: Do both components meet the same compliance requirements?

A: Yes. Both the AS3PK-M3/86A and STTH208U are RoHS3 compliant, REACH unaffected, and classified as EAR99. Both maintain MSL 1 moisture sensitivity level.

Q: What is the difference between avalanche and standard recovery technology?

A: The AS3PK-M3/86A uses avalanche technology, which provides reverse voltage protection through avalanche breakdown characteristics. The STTH208U uses standard recovery technology, which relies on conventional p-n junction rectification. Both are suitable for 800V applications but have different internal structures and performance profiles.

Q: Is inventory availability a factor in substitution?

A: Yes. The STTH208U has significantly higher inventory availability (20,300 pcs) compared to the AS3PK-M3/86A (893 pcs). This may influence supply chain decisions and lead time considerations.