FJAF4210RTU PNP Bipolar Transistor Equivalent & Substitute Parts

Part Overview

The FJAF4210RTU is a PNP bipolar junction transistor manufactured by onsemi, rated for 140 V collector-emitter breakdown voltage and 10 A maximum collector current. This device is packaged in a TO-3PF through-hole configuration and is designed for high-current switching and amplification applications requiring 80 W power dissipation capability.

The FJAF4210RTU is classified as obsolete. Locating equivalent and substitute parts is necessary to support ongoing maintenance, repair, and production requirements for legacy systems utilizing this component. Substitute parts must maintain electrical compatibility across critical parameters including voltage rating, current capacity, power dissipation, and package type.

Key Parameters

Parameter	Value	Unit
Transistor Type	PNP	—
Collector-Emitter Breakdown Voltage (Max)	140	V
Collector Current (Max)	10	A
Power Dissipation (Max)	80	W
Vce Saturation (Max)	500 mV @ 500 mA, 5 A	—
DC Current Gain (hFE Min)	50 @ 3 A, 4 V	—
Transition Frequency	30	MHz
Operating Temperature (Max)	150	°C
Mounting Type	Through Hole	—
Package Type	TO-3PF	—

Substitute Part Grouping Explanation

Substitution eligibility for the FJAF4210RTU is determined by strict adherence to the following electrical and mechanical parameters:

Critical Matching Parameters:

Transistor polarity: PNP
Collector-emitter breakdown voltage: 140 V (maximum)
Maximum collector current: 10 A
Vce saturation: 500 mV @ 500 mA, 5 A
Collector cutoff current: 10 µA (ICBO)
Operating temperature: 150°C (TJ)
Mounting configuration: Through Hole
Package designation: TO-3PF or equivalent TO-3P-3 Full Pack

Allowable Parameter Variations:

DC current gain (hFE) may vary within manufacturer specifications
Power dissipation may equal or exceed 80 W
Transition frequency may equal or exceed 30 MHz
Packaging format (tube, bulk, or full pack) does not affect electrical substitution

Three substitute parts meet these criteria and are listed below.

Parameter Comparison

Parameter	FJAF4210RTU (Main)	FJA4210OTU	FJAF4210OTU	2SA1909
Manufacturer	onsemi	onsemi	Fairchild Semiconductor	Sanken Electric USA Inc.
Transistor Type	PNP	PNP	PNP	PNP
Vce Breakdown (Max)	140 V	140 V	140 V	140 V
Ic (Max)	10 A	10 A	10 A	10 A
Power (Max)	80 W	100 W	80 W	80 W
Vce Saturation (Max)	500 mV @ 500 mA, 5 A	500 mV @ 500 mA, 5 A	500 mV @ 500 mA, 5 A	500 mV @ 500 mA, 5 A
ICBO (Max)	10 µA	10 µA	10 µA	10 µA
hFE (Min) @ Ic, Vce	50 @ 3 A, 4 V	70 @ 3 A, 4 V	70 @ 3 A, 4 V	50 @ 3 A, 4 V
Frequency - Transition	30 MHz	30 MHz	30 MHz	20 MHz
Operating Temperature (Max)	150°C	150°C	150°C	150°C
Mounting Type	Through Hole	Through Hole	Through Hole	Through Hole
Package / Case	TO-3P-3 Full Pack	TO-3P-3, SC-65-3	TO-3P-3 Full Pack	TO-3P-3 Full Pack
Supplier Device Package	TO-3PF	TO-3P	TO-3PF	TO-3PF
Product Status	Obsolete	Obsolete	Active	Active

Engineering Selection Recommendations

FJA4210OTU (onsemi)

The FJA4210OTU is electrically equivalent to the FJAF4210RTU across all critical parameters. This part offers increased power dissipation capability (100 W versus 80 W) and higher minimum DC current gain (70 versus 50 at 3 A, 4 V). The FJA4210OTU is classified as obsolete, matching the status of the main part. Both parts are manufactured by onsemi and share the same base product number (FJA4210), indicating design lineage. The FJA4210OTU is supplied in tube packaging and is available in higher inventory quantities (18,200 units). This part is ROHS3 compliant and REACH unaffected.

FJAF4210OTU (Fairchild Semiconductor)

The FJAF4210OTU maintains full electrical equivalence to the FJAF4210RTU with identical voltage, current, power, and saturation specifications. This part is classified as active, providing long-term availability assurance. The FJAF4210OTU is supplied in bulk packaging and is available in moderate inventory (1,806 units). Both parts share identical part number prefixes (FJAF4210), indicating direct design correspondence. This part is REACH unaffected.

2SA1909 (Sanken Electric USA Inc.)

The 2SA1909 meets all critical electrical parameters of the FJAF4210RTU, including voltage, current, power, and saturation specifications. This part is classified as active and is RoHS compliant, supporting modern supply chain requirements. The 2SA1909 exhibits transition frequency of 20 MHz, which is lower than the 30 MHz specification of the main part; however, this parameter does not prevent substitution in applications where the lower frequency is acceptable. Inventory availability is 715 units. This part is REACH unaffected.

Frequently Asked Questions (FAQ)

Q: Can FJA4210OTU be used as a direct replacement for FJAF4210RTU?

A: Yes. The FJA4210OTU meets all critical electrical specifications of the FJAF4210RTU, including 140 V breakdown voltage, 10 A collector current, 500 mV saturation voltage, and 150°C operating temperature. Both parts are through-hole mounted in TO-3P package configurations. The primary difference is packaging format (tube versus full pack), which does not affect electrical performance.

Q: What is the difference between TO-3PF and TO-3P package designations?

A: TO-3PF and TO-3P are both through-hole mounted packages in the TO-3 family with three leads. The designations reflect supplier packaging conventions. Both packages are mechanically and electrically compatible for board-level mounting and circuit operation. The FJAF4210RTU uses TO-3PF designation, while FJA4210OTU uses TO-3P designation; both are functionally equivalent.

Q: Is the 2SA1909 suitable for applications requiring 30 MHz transition frequency?

A: The 2SA1909 is rated for 20 MHz transition frequency, which is lower than the 30 MHz specification of the FJAF4210RTU. Substitution is appropriate only in applications where the lower transition frequency does not compromise circuit performance. Applications requiring minimum 30 MHz frequency response should use FJA4210OTU or FJAF4210OTU.

Q: Why does FJA4210OTU have higher power dissipation (100 W) than FJAF4210RTU (80 W)?

A: The FJA4210OTU is rated for 100 W maximum power dissipation, while the FJAF4210RTU is rated for 80 W. This difference reflects thermal design variations between the two parts. The higher power rating of FJA4210OTU does not prevent substitution; it indicates enhanced thermal capability. Applications designed for 80 W operation remain within the safe operating limits of FJA4210OTU.

Q: Are there compliance or certification differences between the substitute parts?

A: FJAF4210OTU (Fairchild Semiconductor) is ROHS3 compliant. The 2SA1909 is RoHS compliant. FJA4210OTU does not list RoHS status. All three substitute parts are REACH unaffected. Applications requiring specific compliance certifications should verify alignment with system-level requirements.

Q: What is the inventory status of each substitute part?

A: FJA4210OTU has the highest inventory availability at 18,200 units. FJAF4210OTU has 1,806 units in stock. The 2SA1909 has 715 units available. The FJAF4210RTU (main part) has 841 units in stock. Inventory levels should be verified with suppliers for current availability.

Q: Can these parts be used interchangeably in existing circuit designs?

A: Yes, within the constraints of the electrical specifications provided. All substitute parts maintain identical collector-emitter breakdown voltage (140 V), maximum collector current (10 A), saturation voltage (500 mV), and operating temperature (150°C). Pin configurations and through-hole mounting are compatible. Circuit designs do not require modification for substitution.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message