FESF8HT-E3/45 Equivalent & Substitute Parts

Part Overview

The FESF8HT-E3/45 is a general-purpose rectifier diode manufactured by Vishay General Semiconductor - Diodes Division. This through-hole component operates at 500 V DC reverse voltage with an 8 A average rectified current rating and features fast recovery characteristics with a 50 ns reverse recovery time. The device is housed in a TO-220-2 Full Pack isolated tab package and is classified as Active product status with ROHS3 compliance and unlimited moisture sensitivity level.

Equivalent and substitute parts are identified to address inventory availability, supply chain continuity, and application-specific requirements while maintaining electrical and mechanical compatibility within the general-purpose rectifier diode category.

Substiute Parts

FESF8HT-E3/45

Vishay General Semiconductor - Diodes DivisionIn Stock: 1169FESF8HT-E3/45 Datasheet

Current PartRFQ

STTH8L06FP

STMicroelectronicsIn Stock: 19876STTH8L06FP Datasheet

DirectRFQ

STTH8R06FP

STMicroelectronicsIn Stock: 65455STTH8R06FP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the FESF8HT-E3/45 are qualified based on the following electrical and mechanical parameters:

Critical Matching Parameters:

• Current - Average Rectified (Io): 8 A (exact match required)
• Mounting Type: Through Hole (exact match required)
• Package / Case: TO-220-2 Full Pack configuration (exact match required)
• Speed Classification: Fast Recovery ≤ 500ns, > 200mA (exact match required)
• RoHS Status: ROHS3 Compliant (exact match required)

Allowable Variation Parameters:

• Voltage - DC Reverse (Vr) (Max): Substitute must equal or exceed 500 V
• Voltage - Forward (Vf) (Max) @ If: Substitute values within acceptable operating range
• Reverse Recovery Time (trr): Substitute must meet fast recovery classification
• Current - Reverse Leakage @ Vr: Substitute values within acceptable operating range
• Operating Temperature - Junction (Max): Substitute must support application requirements

The identified substitute parts STTH8L06FP and STTH8R06FP from STMicroelectronics meet all critical matching parameters and allowable variation criteria for general-purpose rectifier diode applications.

Parameter Comparison

Engineering Selection Recommendations

STTH8L06FP Selection Criteria: The STTH8L06FP is suitable for applications requiring direct electrical compatibility with the FESF8HT-E3/45. This substitute provides 600 V reverse voltage rating, exceeding the original 500 V specification, and delivers lower forward voltage drop (1.3 V versus 1.5 V at 8 A). The device maintains fast recovery characteristics and ROHS3 compliance. Operating temperature maximum of 175°C provides extended thermal headroom compared to the original 150°C rating.

STTH8R06FP Selection Criteria: The STTH8R06FP is the manufacturer-recommended substitute from STMicroelectronics. This part matches all critical electrical parameters including 8 A current rating and fast recovery classification. The 600 V reverse voltage rating exceeds the original specification. The reverse recovery time of 45 ns is superior to the original 50 ns specification. ROHS3 compliance and 175°C maximum junction temperature are maintained. Note that forward voltage drop is elevated at 2.9 V @ 8 A compared to the original 1.5 V specification.

Both substitute parts are Active product status with unlimited moisture sensitivity level and REACH unaffected status, matching the compliance profile of the original component.

Frequently Asked Questions (FAQ)

Q: Can STTH8L06FP and STTH8R06FP be used interchangeably with FESF8HT-E3/45?

A: Both substitute parts meet the critical electrical and mechanical parameters for general-purpose rectifier diode applications. They share identical 8 A current rating, fast recovery classification, through-hole mounting, and TO-220-2 package configuration. The primary difference is forward voltage drop: STTH8L06FP at 1.3 V and STTH8R06FP at 2.9 V versus the original 1.5 V at 8 A. Application thermal and power dissipation requirements determine which substitute is appropriate.

Q: What is the voltage rating difference between the original part and substitutes?

A: The FESF8HT-E3/45 operates at 500 V DC reverse voltage maximum. Both substitute parts (STTH8L06FP and STTH8R06FP) are rated for 600 V DC reverse voltage maximum. This higher rating provides additional design margin and does not create compatibility issues in applications designed for 500 V operation.

Q: Are there package differences between these parts?

A: The FESF8HT-E3/45 and STTH8L06FP both feature TO-220-2 Full Pack with isolated tab configuration. The STTH8R06FP uses TO-220-2 Full Pack without the isolated tab designation. All three parts are through-hole mounted in TO-220-2 packages suitable for identical PCB footprints and thermal management approaches.

Q: How do reverse recovery times compare?

A: The FESF8HT-E3/45 specifies 50 ns reverse recovery time. The STTH8L06FP provides 105 ns, and the STTH8R06FP provides 45 ns. All three parts meet the fast recovery classification of ≤ 500 ns for currents > 200 mA. Applications with specific switching frequency or EMI requirements should evaluate reverse recovery time impact.

Q: What are the compliance and regulatory differences?

A: All three parts maintain ROHS3 compliance, unlimited moisture sensitivity level (MSL 1), and REACH unaffected status. No regulatory or compliance barriers exist for substitution between these parts.

Q: Which substitute should be selected for thermal-constrained applications?

A: Both substitute parts support maximum junction temperature of 175°C, compared to the original part's 150°C rating. This provides 25°C additional thermal margin. Forward voltage drop differences (STTH8L06FP at 1.3 V versus STTH8R06FP at 2.9 V) directly impact power dissipation and thermal performance in high-current applications.