2N685 Equivalent & Substitute Parts

Part Overview

The 2N685 is a standard recovery SCR (silicon-controlled rectifier) rated for 200V off-state voltage and 25A RMS on-state current in a TO-48 chassis mount stud package. Manufactured by Central Semiconductor Corp, this component is classified as obsolete, making equivalent substitutes necessary for new designs and ongoing production requirements. The part operates across a temperature range of -65°C to 125°C and is suitable for power control applications requiring thyristor switching functionality.

Substiute Parts

2N685

Central Semiconductor CorpIn Stock: 9242N685 Datasheet

Current PartRFQ

VS-2N685

Vishay General Semiconductor - Diodes DivisionIn Stock: 904VS-2N685 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 2N685 is determined by matching the following critical electrical and mechanical parameters:

• Voltage Rating (Off-State): 200V minimum
• Current Rating (RMS On-State): 25A minimum
• Gate Trigger Characteristics: Vgt ≤ 2V, Igt ≤ 40mA
• On-State Voltage Drop: Vtm ≤ 2V
• Package Compatibility: TO-48 or equivalent TO-208AA stud mount configuration
• SCR Type: Standard Recovery
• Operating Temperature Range: -65°C to 125°C minimum

The VS-2N685 manufactured by Vishay General Semiconductor meets all substitution criteria. Both parts share identical voltage ratings, gate trigger specifications, temperature operating range, and mechanical mounting configuration. The VS-2N685 is designated as the manufacturer-recommended substitute and maintains functional equivalence for the obsolete 2N685.

Parameter Comparison

Engineering Selection Recommendations

The VS-2N685 is the direct substitute for the obsolete 2N685. Selection is based on the following factors:

Product Status: The 2N685 is obsolete and no longer manufactured. The VS-2N685 is active production and available in inventory.

Electrical Equivalence: All critical electrical parameters match or exceed the original specification. The VS-2N685 demonstrates superior leakage current performance (6mA vs. 12mA off-state) and lower holding current (20mA vs. 100mA), providing improved efficiency characteristics.

Compliance: The VS-2N685 is ROHS3 compliant and REACH unaffected, meeting modern regulatory requirements. The original 2N685 is RoHS non-compliant.

Mechanical Compatibility: Both parts use identical TO-48 stud mount packaging, ensuring direct mechanical substitution in existing designs without layout modifications.

Thermal Performance: Operating temperature range is identical across both parts, supporting equivalent thermal design margins.

Frequently Asked Questions (FAQ)

Q: Can the VS-2N685 directly replace the 2N685 in existing circuits?

A: Yes. The VS-2N685 meets all electrical and mechanical specifications of the 2N685. Gate trigger voltage, on-state voltage drop, RMS current rating, and package configuration are identical. Direct substitution is supported without circuit modification.

Q: What are the key differences between the 2N685 and VS-2N685?

A: The VS-2N685 offers improved leakage current performance (6mA vs. 12mA) and lower holding current (20mA vs. 100mA). The VS-2N685 is ROHS3 compliant, while the 2N685 is not. Both parts are electrically and mechanically equivalent for switching applications.

Q: Is the TO-208AA package compatible with TO-48 mounting?

A: Yes. The TO-208AA and TO-48 designations refer to the same stud mount package configuration. Both the 2N685 and VS-2N685 use this package type and are mechanically interchangeable.

Q: What is the significance of the lower holding current in the VS-2N685?

A: Lower holding current (Ih) reduces the gate current required to maintain SCR conduction after triggering. This improves circuit efficiency and reduces gate drive power dissipation, providing a performance advantage in the substitute part.

Q: Are there any temperature or voltage derating considerations when substituting?

A: No. Both parts operate across -65°C to 125°C and are rated for 200V off-state voltage. Thermal and voltage derating curves remain equivalent, and existing design margins apply directly to the VS-2N685.

Q: What certifications does the VS-2N685 carry?

A: The VS-2N685 is ROHS3 compliant and REACH unaffected. It carries EAR99 export classification. The original 2N685 does not meet modern RoHS requirements.