2SC3979A Equivalent & Substitute Parts

Part Overview

The 2SC3979A is an NPN bipolar junction transistor manufactured by Panasonic Electronic Components, rated for 800 V collector-emitter breakdown voltage and 3 A maximum collector current. This device is packaged in a TO-220F-A1 through-hole configuration and is designed for high-voltage switching applications with a maximum power dissipation of 2 W.

The 2SC3979A is classified as an obsolete product. Equivalent and substitute parts are necessary to maintain design continuity and ensure component availability for production, repair, and maintenance applications where this transistor is specified in existing designs.

Substiute Parts

2SC3979A

Panasonic Electronic ComponentsIn Stock: 11152SC3979A Datasheet

Current PartRFQ

2SC4304

Sanken Electric USA Inc.In Stock: 40582SC4304 Datasheet

SimilarRFQ

FJP5027OTU

onsemiIn Stock: 32620FJP5027OTU Datasheet

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KSC5603DTU

onsemiIn Stock: 2375KSC5603DTU Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the 2SC3979A is determined by strict equivalence in the following electrical and mechanical parameters:

Critical Matching Parameters:

• Transistor Type: NPN
• Voltage - Collector Emitter Breakdown (Max): 800 V
• Current - Collector (Ic) (Max): 3 A
• Mounting Type: Through Hole
• Package / Case: TO-220-3 or compatible variant (TO-220F-A1, TO-220F, TO-220-3)
• Operating Temperature (TJ): 150°C

All substitute parts listed meet or exceed these critical parameters. Substitute parts may differ in secondary characteristics such as power dissipation, transition frequency, saturation voltage, and DC current gain, provided the critical parameters remain equivalent or superior.

Parameter Comparison

Engineering Selection Recommendations

2SC4304 (Sanken Electric USA Inc.)

The 2SC4304 is an active product with electrical ratings equivalent to the 2SC3979A. This part provides improved saturation voltage performance (500 mV versus 1.5 V) and higher transition frequency (15 MHz versus 10 MHz). Power dissipation capability is significantly higher at 35 W. The 2SC4304 is suitable for direct substitution in applications where the original 2SC3979A specifications are met or exceeded. RoHS compliance is confirmed.

FJP5027OTU (onsemi)

The FJP5027OTU is an active product with electrical ratings equivalent to the 2SC3979A. This part offers the highest power dissipation capability at 50 W and superior collector cutoff current performance (10 µA). Transition frequency is 15 MHz. The FJP5027OTU is packaged in standard TO-220-3 configuration and carries ROHS3 compliance and REACH unaffected status. This part is suitable for applications requiring enhanced thermal performance.

KSC5603DTU (onsemi)

The KSC5603DTU is an active product with electrical ratings equivalent to the 2SC3979A. This part provides the highest power dissipation capability at 100 W and improved DC current gain (20 minimum). Transition frequency is 5 MHz, which is lower than the original part. The KSC5603DTU is packaged in standard TO-220-3 configuration and carries ROHS3 compliance and REACH unaffected status. This part is suitable for applications where maximum thermal dissipation is required and lower switching frequency is acceptable.

All three substitute parts are active products with confirmed availability and compliance certifications, providing alternatives to the obsolete 2SC3979A.

Frequently Asked Questions (FAQ)

Q: Can the 2SC4304 be used as a direct replacement for the 2SC3979A?

A: Yes. The 2SC4304 meets all critical electrical parameters: 800 V breakdown voltage, 3 A maximum collector current, NPN type, and TO-220-3 package. The 2SC4304 is an active product with improved performance characteristics in saturation voltage and transition frequency.

Q: What is the primary difference between the FJP5027OTU and KSC5603DTU?

A: Both parts meet the critical electrical specifications of the 2SC3979A. The FJP5027OTU has a transition frequency of 15 MHz and 50 W power dissipation. The KSC5603DTU has a transition frequency of 5 MHz and 100 W power dissipation. Selection depends on the application's frequency and thermal requirements.

Q: Are all substitute parts available in the same package as the 2SC3979A?

A: All substitute parts use the TO-220-3 through-hole package family. The 2SC3979A uses TO-220F-A1, while the 2SC4304 uses TO-220F, and both FJP5027OTU and KSC5603DTU use standard TO-220-3. These packages are mechanically and electrically compatible for through-hole mounting applications.

Q: Which substitute part has the best saturation voltage performance?

A: The 2SC4304 has the lowest saturation voltage at 500 mV (measured at 140 mA base current and 700 mA collector current), compared to 1.5 V for the 2SC3979A. This provides improved switching efficiency in saturation mode.

Q: Are the substitute parts RoHS compliant?

A: The 2SC4304 is RoHS compliant. The FJP5027OTU and KSC5603DTU are ROHS3 compliant. All parts meet current environmental compliance standards.

Q: What is the moisture sensitivity level of the substitute parts?

A: The 2SC4304 has MSL 1 (Unlimited), indicating no moisture sensitivity restrictions. The FJP5027OTU and KSC5603DTU have MSL Not Applicable, indicating no moisture sensitivity concerns for these through-hole packaged devices.

Q: Can I use the KSC5603DTU in a high-frequency switching application?

A: The KSC5603DTU has a transition frequency of 5 MHz, which is lower than the original 2SC3979A (10 MHz). For applications requiring higher switching frequencies, the 2SC4304 or FJP5027OTU (both 15 MHz) are more appropriate selections.