BF240_J35Z Equivalent & Substitute Parts

Part Overview

The BF240_J35Z is an RF transistor NPN manufactured by onsemi, rated for 40V collector-emitter breakdown voltage with a transition frequency of 1.1GHz and maximum power dissipation of 350mW. This device is packaged in a through-hole TO-92-3 configuration and is classified as obsolete. Due to its obsolete status, equivalent substitute parts are necessary for new designs and ongoing production requirements. Substitute parts must maintain functional compatibility within RF applications while accommodating modern packaging and manufacturing standards.

Key Parameters

Parameter	BF240_J35Z
Manufacturer	onsemi
Transistor Type	NPN
Voltage - Collector Emitter Breakdown (Max)	40V
Frequency - Transition	1.1GHz
Power - Max	350mW
DC Current Gain (hFE) (Min) @ Ic, Vce	65 @ 1mA, 10V
Current - Collector (Ic) (Max)	50mA
Mounting Type	Through Hole
Package / Case	TO-226-3, TO-92-3
Product Status	Obsolete
Moisture Sensitivity Level (MSL)	1 (Unlimited)

Substitute Part Grouping Explanation

Substitution of the BF240_J35Z is determined by the following critical parameters:

Electrical Compatibility Criteria:

Transistor Type: NPN configuration required
Voltage - Collector Emitter Breakdown: Minimum 40V or higher
Frequency - Transition: Minimum 1.1GHz or higher
Power - Max: Minimum 350mW or higher
Current - Collector (Ic) (Max): Minimum 50mA or higher
DC Current Gain (hFE): Comparable performance at specified operating points

Mechanical & Manufacturing Criteria:

Mounting Type: Through-hole or surface-mount alternatives acceptable for redesign
Package compatibility: Modern packaging standards (SMD, SOIC, SOT-23) acceptable for new designs
Product Status: Active status preferred for long-term availability

The substitute parts listed below meet or exceed the electrical specifications of the BF240_J35Z while offering active product status and modern packaging options suitable for current manufacturing processes.

Parameter Comparison

Parameter	BF240_J35Z	MAX2602ESA+T	MRF10031	BFP843FH6327XTSA1	BFS17NQTA	BFR340L3E6327XTMA1
Manufacturer	onsemi	Analog Devices Inc./Maxim Integrated	MACOM Technology Solutions	Infineon Technologies	Diodes Incorporated	Infineon Technologies
Transistor Type	NPN	NPN	NPN	NPN	NPN	NPN
Voltage - Collector Emitter Breakdown (Max)	40V	15V	55V	2.25V	11V	9V
Frequency - Transition	1.1GHz	1GHz	—	—	3.2GHz	14GHz
Power - Max	350mW	6.4W	30W	125mW	310mW	60mW
DC Current Gain (hFE) (Min) @ Ic, Vce	65 @ 1mA, 10V	100 @ 250mA, 3V	20 @ 500mA, 5V	150 @ 15mA, 1.8V	56 @ 5mA, 10V	90 @ 5mA, 3V
Current - Collector (Ic) (Max)	50mA	1.2A	3A	55mA	50mA	10mA
Mounting Type	Through Hole	Surface Mount	Chassis Mount	Surface Mount	Surface Mount	Surface Mount
Package / Case	TO-226-3, TO-92-3	8-SOIC (0.154", 3.90mm Width) Exposed Pad	332A-03	4-SMD, Flat Leads	TO-236-3, SC-59, SOT-23-3	SC-101, SOT-883
Product Status	Obsolete	Active	Active	Active	Active	Active
RoHS Status	—	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
Moisture Sensitivity Level (MSL)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)

Engineering Selection Recommendations

MAX2602ESA+T (Analog Devices Inc./Maxim Integrated)

Active product status with ROHS3 compliance
Exceeds power dissipation requirement (6.4W vs. 350mW)
Collector-emitter breakdown voltage of 15V is below the 40V specification; suitable for applications with reduced voltage requirements
Higher current capability (1.2A) and gain (11.6dB) provide enhanced performance margin
8-SOIC-EP surface-mount package requires PCB redesign from through-hole configuration

MRF10031 (MACOM Technology Solutions)

Active product status with ROHS3 compliance
Exceeds voltage specification (55V vs. 40V)
Significantly higher power dissipation (30W) and current capability (3A)
Chassis-mount configuration suitable for high-power RF applications
Requires mechanical redesign and different mounting infrastructure

BFP843FH6327XTSA1 (Infineon Technologies)

Active product status with ROHS3 compliance
Collector-emitter breakdown voltage of 2.25V is substantially below specification; not suitable for 40V applications
Current capability (55mA) meets specification
Power dissipation (125mW) is below requirement
Surface-mount PG-TSFP-4-1 package requires PCB redesign

BFS17NQTA (Diodes Incorporated)

Active product status with ROHS3 compliance
Collector-emitter breakdown voltage of 11V is below specification; suitable for reduced voltage applications
Transition frequency of 3.2GHz exceeds requirement
Power dissipation (310mW) approaches specification
Current capability (50mA) meets specification
SOT-23-3 surface-mount package is compact and widely supported

BFR340L3E6327XTMA1 (Infineon Technologies)

Active product status with ROHS3 compliance
Collector-emitter breakdown voltage of 9V is below specification
Transition frequency of 14GHz significantly exceeds requirement
Power dissipation (60mW) is substantially below requirement
Current capability (10mA) is below specification
SC-101/SOT-883 surface-mount package is ultra-compact

Frequently Asked Questions (FAQ)

Q: Can the BF240_J35Z be directly replaced with any of these substitute parts?

A: Direct replacement depends on application voltage and current requirements. The BF240_J35Z operates at 40V maximum collector-emitter breakdown voltage. Only MRF10031 (55V) meets or exceeds this specification. Other substitutes operate at lower voltages (2.25V to 15V) and are suitable only for applications with reduced voltage requirements.

Q: What is the primary reason for finding substitutes for the BF240_J35Z?

A: The BF240_J35Z is classified as obsolete. Substitute parts with active product status ensure long-term availability, manufacturing support, and compliance with current industry standards including ROHS3 requirements.

Q: Are surface-mount substitutes compatible with through-hole PCB designs?

A: Surface-mount packages (SOT-23, SOIC, TSFP, TSLP) require PCB redesign and different assembly processes compared to through-hole TO-92-3 packaging. Mechanical and electrical layout modifications are necessary. Through-hole alternatives are limited among active products; MRF10031 uses chassis-mount configuration requiring different mechanical integration.

Q: Which substitute offers the closest electrical match to the BF240_J35Z?

A: BFS17NQTA provides the closest match in terms of current capability (50mA), power dissipation (310mW), and transition frequency (3.2GHz). However, its 11V collector-emitter breakdown voltage is below the 40V specification. For applications requiring 40V operation, MRF10031 is the only substitute meeting this requirement.

Q: What compliance certifications are important for substitute selection?

A: All active substitute parts listed carry ROHS3 compliance and MSL Level 1 (Unlimited) moisture sensitivity rating, matching the environmental and regulatory requirements of the original BF240_J35Z. REACH compliance is unaffected for all parts.

Q: Can multiple substitutes be used interchangeably in the same application?

A: No. Each substitute has distinct electrical characteristics. Selection must be based on specific application requirements for voltage, current, frequency, and power dissipation. Circuit redesign and validation are required when changing from the BF240_J35Z to any substitute part.

Q: What is the inventory status of these substitute parts?

A: All substitute parts listed are in active production with substantial inventory availability: MAX2602ESA+T (2,963 pcs), MRF10031 (1,405 pcs), BFP843FH6327XTSA1 (1,285 pcs), BFS17NQTA (24,300 pcs), and BFR340L3E6327XTMA1 (20,200 pcs).

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message