STTH8R04G Equivalent & Substitute Parts

Part Overview

The STTH8R04G is a general-purpose rectifier diode manufactured by STMicroelectronics, rated for 400 V DC reverse voltage and 8 A average rectified current in a surface mount D2PAK package. This part is classified as obsolete, making identification of equivalent and substitute components necessary for ongoing design support, maintenance, and production continuity. Substitute parts must maintain electrical and mechanical compatibility while meeting the same functional requirements for fast recovery rectification applications.

Substiute Parts

STTH8R04G

STMicroelectronicsIn Stock: 1261STTH8R04G Datasheet

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STTH8R04G-TR

STMicroelectronicsIn Stock: 20433STTH8R04G-TR Datasheet

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SDURB840

SMC Diode SolutionsIn Stock: 1618SDURB840 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the STTH8R04G is determined by strict equivalence across the following electrical and mechanical parameters:

Primary Substitution Criteria:

• Voltage - DC Reverse (Vr) (Max): 400 V minimum
• Current - Average Rectified (Io): 8 A minimum
• Package / Case: TO-263-3, D2PAK (2 Leads + Tab), TO-263AB
• Mounting Type: Surface Mount
• Speed Classification: Fast Recovery ≤ 500ns, > 200mA (Io)

Secondary Compatibility Parameters:

• Voltage - Forward (Vf) (Max) @ If: Equal or lower forward voltage drop
• Reverse Recovery Time (trr): Equal or lower recovery time
• Current - Reverse Leakage @ Vr: Equal or lower leakage current
• Operating Temperature - Junction: Must encompass or exceed the original range
• RoHS and MSL Compliance: Must maintain regulatory compliance

Parts meeting all primary criteria and maintaining or improving secondary parameters are classified as direct substitutes.

Parameter Comparison

Engineering Selection Recommendations

STTH8R04G-TR (STMicroelectronics)

The STTH8R04G-TR is the primary substitute for the obsolete STTH8R04G. Both parts are manufactured by STMicroelectronics and share identical electrical specifications across all critical parameters: 400 V reverse voltage, 8 A average rectified current, 1.5 V forward voltage drop, and 50 ns reverse recovery time. The STTH8R04G-TR maintains active product status, ensuring long-term availability and supply chain continuity. Packaging differs only in format (Tape & Reel versus bulk), which does not affect electrical or mechanical compatibility. Both parts are ROHS3 compliant with MSL 1 rating and identical operating temperature ranges (-40°C to 175°C). Selection of STTH8R04G-TR is recommended for direct replacement in all applications previously using STTH8R04G.

SDURB840 (SMC Diode Solutions)

The SDURB840 is an alternative substitute manufactured by SMC Diode Solutions. This part meets all primary substitution criteria: 400 V reverse voltage, 8 A average rectified current, D2PAK surface mount package, and fast recovery classification. The SDURB840 demonstrates improved performance characteristics compared to the original part: forward voltage drop is reduced to 1.3 V (versus 1.5 V), and reverse recovery time is shortened to 45 ns (versus 50 ns). Both improvements reduce power dissipation and switching losses. The SDURB840 operates across a wider temperature range (-55°C to 150°C), providing enhanced low-temperature performance. ROHS3 compliance and MSL 1 rating are maintained. The SDURB840 is suitable for applications where improved efficiency and extended low-temperature operation are beneficial. REACH status differs (REACH Affected versus REACH Unaffected for STMicroelectronics parts), which may affect supply chain considerations in specific regulatory jurisdictions.

Frequently Asked Questions (FAQ)

Q: Can STTH8R04G-TR be used as a direct replacement for STTH8R04G?

A: Yes. The STTH8R04G-TR is electrically and mechanically identical to STTH8R04G. The only difference is packaging format: STTH8R04G-TR is supplied in Tape & Reel format for automated assembly, while STTH8R04G is supplied in bulk. Both parts share the same D2PAK surface mount package, electrical ratings, and performance characteristics. STTH8R04G-TR is the recommended substitute due to its active product status.

Q: What are the advantages of using SDURB840 instead of STTH8R04G-TR?

A: The SDURB840 offers two performance improvements: lower forward voltage drop (1.3 V versus 1.5 V at 8 A) and faster reverse recovery time (45 ns versus 50 ns). These characteristics reduce power dissipation and switching losses in rectification circuits. The SDURB840 also operates at lower junction temperatures (-55°C minimum versus -40°C minimum), providing enhanced performance in cold environments. These advantages come from a different manufacturer (SMC Diode Solutions), which may affect supply chain and qualification requirements.

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

A: Yes. STTH8R04G, STTH8R04G-TR, and SDURB840 all use the TO-263-3 D2PAK package with identical pin configuration and mechanical dimensions. No PCB layout modifications are required when substituting between these parts. Thermal management considerations remain consistent due to identical package geometry.

Q: What is the difference between STTH8R04G and STTH8R04G-TR packaging?

A: STTH8R04G is supplied in bulk packaging, while STTH8R04G-TR is supplied in Tape & Reel (TR) format. Tape & Reel packaging is optimized for automated pick-and-place assembly and high-volume production. Bulk packaging is suitable for manual assembly or lower-volume applications. Electrical and mechanical specifications are identical; packaging format selection depends on assembly process requirements.

Q: Can SDURB840 be used in applications with operating temperatures above 150°C?

A: No. The SDURB840 maximum junction temperature is 150°C, which is lower than the STTH8R04G and STTH8R04G-TR maximum of 175°C. Applications requiring sustained operation above 150°C must use STTH8R04G-TR. For applications operating between 150°C and 175°C, STTH8R04G-TR is the only suitable substitute.

Q: Are there compliance or regulatory differences between these parts?

A: All three parts are ROHS3 compliant and carry MSL 1 (Unlimited) moisture sensitivity rating. REACH status differs: STTH8R04G and STTH8R04G-TR are REACH Unaffected, while SDURB840 is REACH Affected. This distinction may impact supply chain decisions in jurisdictions with specific REACH requirements. Both ECCN and HTSUS classifications are identical across all three parts.

Q: What is the reverse recovery time, and why does it matter?

A: Reverse recovery time (trr) is the interval required for a diode to transition from forward conduction to reverse blocking after the applied voltage reverses. STTH8R04G and STTH8R04G-TR have trr of 50 ns, while SDURB840 has trr of 45 ns. Shorter recovery time reduces switching losses and electromagnetic interference in high-frequency rectification circuits. The 5 ns difference is significant in applications operating above 100 kHz.

Q: Is the forward voltage drop difference between STTH8R04G-TR (1.5 V) and SDURB840 (1.3 V) significant?

A: The 0.2 V difference represents approximately 13% lower forward voltage drop in the SDURB840. At 8 A continuous current, this translates to 1.6 W lower power dissipation per diode. In high-current or high-frequency applications, this reduction improves thermal performance and overall circuit efficiency. For low-current or intermittent applications, the difference is negligible.