Equivalent & Substitute Parts for 2SC3979

Part Overview

The Panasonic 2SC3979 is an NPN bipolar junction transistor rated for 800 V collector-emitter breakdown voltage and 3 A maximum collector current. Designed for through-hole mounting in TO-220F-A1 package configuration, this component is classified as obsolete. Due to its obsolete status, equivalent substitute parts with matching or superior electrical and mechanical specifications are necessary for ongoing design support and production continuity.

Key Parameters

Parameter	Value	Unit
Transistor Type	NPN	—
Voltage - Collector Emitter Breakdown (Max)	800	V
Current - Collector (Ic) (Max)	3	A
Power - Max	2	W
Frequency - Transition	10	MHz
Operating Temperature (TJ)	150	°C
Mounting Type	Through Hole	—
Package / Case	TO-220-3	—

Substitute Part Grouping Explanation

Substitution of the 2SC3979 is determined by strict equivalence in the following critical parameters:

Mandatory 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 family

Acceptable Variation Parameters:

Power - Max: Equal to or greater than 2 W
Frequency - Transition: Equal to or greater than 10 MHz
Operating Temperature: Equal to or greater than 150°C

All three substitute parts (2SC4304, FJP5027OTU, KSC5603DTU) meet or exceed the mandatory matching parameters and acceptable variation thresholds. These parts are classified as active products with current manufacturing status, ensuring long-term availability and supply chain stability.

Parameter Comparison

Parameter	2SC3979 (Main)	2SC4304	FJP5027OTU	KSC5603DTU
Manufacturer	Panasonic Electronic Components	Sanken Electric USA Inc.	onsemi	onsemi
Product Status	Obsolete	Active	Active	Active
Transistor Type	NPN	NPN	NPN	NPN
Voltage - Collector Emitter Breakdown (Max)	800 V	800 V	800 V	800 V
Current - Collector (Ic) (Max)	3 A	3 A	3 A	3 A
Vce Saturation (Max)	1.5 V @ 160mA, 800mA	500 mV @ 140mA, 700mA	2 V @ 300mA, 1.5A	2.5 V @ 200µA, 1A
Current - Collector Cutoff (Max)	50 µA	100 µA	10 µA	100 µA
DC Current Gain (hFE) (Min)	6 @ 800mA, 5V	10 @ 700mA, 4V	20 @ 200mA, 5V	20 @ 400mA, 3V
Power - Max	2 W	35 W	50 W	100 W
Frequency - Transition	10 MHz	15 MHz	15 MHz	5 MHz
Operating Temperature (TJ)	150°C	150°C	150°C	150°C
Mounting Type	Through Hole	Through Hole	Through Hole	Through Hole
Package / Case	TO-220-3	TO-220-3	TO-220-3	TO-220-3
RoHS Status	Not specified	RoHS Compliant	ROHS3 Compliant	ROHS3 Compliant
Moisture Sensitivity Level (MSL)	1 (Unlimited)	1 (Unlimited)	Not Applicable	Not Applicable

Engineering Selection Recommendations

2SC4304 (Sanken Electric USA Inc.): This substitute provides active product status with RoHS compliance certification. The 35 W power rating exceeds the 2SC3979 specification by a factor of 17.5, and the 15 MHz transition frequency surpasses the original 10 MHz requirement. The lower saturation voltage (500 mV) and higher DC current gain (10) improve switching performance. This part is suitable for direct replacement in applications where enhanced thermal dissipation capability is beneficial.

FJP5027OTU (onsemi): This substitute offers the highest power dissipation rating at 50 W with ROHS3 compliance and REACH unaffected status. The 15 MHz transition frequency and superior DC current gain (20) provide enhanced switching characteristics. The lower collector cutoff current (10 µA) indicates reduced leakage. This part accommodates applications requiring higher power handling and improved frequency response.

KSC5603DTU (onsemi): This substitute delivers the maximum power rating at 100 W with ROHS3 compliance and REACH unaffected status. However, the 5 MHz transition frequency is below the 2SC3979 specification of 10 MHz. This part is suitable for low-frequency, high-power applications where thermal management is critical and switching speed requirements do not exceed 5 MHz.

Frequently Asked Questions (FAQ)

Q: Can the 2SC4304 directly replace the 2SC3979 in all applications?

A: The 2SC4304 meets all mandatory electrical parameters (800 V, 3 A, NPN type) and package requirements (TO-220-3). The enhanced power rating (35 W vs. 2 W) and improved transition frequency (15 MHz vs. 10 MHz) make it suitable for direct replacement. Active product status ensures supply continuity.

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

A: Both parts share identical voltage and current ratings. The FJP5027OTU operates at 15 MHz transition frequency with 50 W power dissipation, while the KSC5603DTU operates at 5 MHz with 100 W power dissipation. Selection depends on application frequency requirements and thermal design constraints.

Q: Are all substitute parts RoHS compliant?

A: The 2SC4304 is RoHS Compliant. The FJP5027OTU and KSC5603DTU are ROHS3 Compliant. All three substitutes meet current environmental compliance standards.

Q: Does package compatibility require any PCB modifications?

A: All substitute parts use TO-220-3 package configuration, identical to the 2SC3979. No PCB layout modifications are required for mechanical fit or pin assignment.

Q: Which substitute offers the best thermal performance?

A: The KSC5603DTU provides the highest power dissipation rating at 100 W, offering superior thermal performance for applications requiring maximum heat dissipation capability.

Q: Is the 2SC3979 still available for procurement?

A: The 2SC3979 is classified as obsolete. Current inventory of 2400 pieces is available, but long-term supply cannot be guaranteed. Migration to active substitute parts is recommended for new designs and production continuity.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message