MMBF4119 Equivalent & Substitute Parts

Part Overview

The MMBF4119 is an N-Channel JFET transistor manufactured by onsemi, designed for surface mount applications in the SOT-23-3 package. This device operates at a maximum breakdown voltage of 40 V with a power dissipation rating of 225 mW and a drain current (Idss) of 200 µA at 10 V. The MMBF4119 is classified as obsolete, making identification of functionally equivalent substitute parts essential for ongoing design support and production continuity.

Substiute Parts

MMBF4119

onsemiIn Stock: 26186MMBF4119 Datasheet

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2SK545-11D-TB-E

onsemiIn Stock: 7142SK545-11D-TB-E Datasheet

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MMBFJ201

onsemiIn Stock: 76135MMBFJ201 Datasheet

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2SK209-GR(TE85L,F)

Toshiba Semiconductor and StorageIn Stock: 22122SK209-GR(TE85L,F) Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the MMBF4119 is determined by the following critical parameters:

• FET Type: N-Channel configuration
• Voltage Rating: Minimum 40 V breakdown voltage (V(BR)GSS)
• Package Compatibility: SOT-23-3 / SC-59 / TO-236-3 surface mount packages
• Drain Current Characteristics: Idss and VGS(off) specifications must support the intended application
• Power Dissipation: Maximum power rating must meet or exceed 225 mW
• Operating Temperature Range: -55°C to 150°C (TJ)

Substitute parts are grouped based on matching these electrical and mechanical parameters. Parts with identical or superior voltage ratings, compatible package types, and comparable drain current characteristics are considered functionally equivalent.

Parameter Comparison

Engineering Selection Recommendations

MMBFJ201 is the primary recommended substitute for the MMBF4119. Both devices share identical voltage ratings (40 V), matching package specifications (SOT-23-3), and comparable drain current characteristics (200 µA). The MMBFJ201 is currently in active production status with ROHS3 compliance, providing long-term availability and regulatory alignment. The higher power dissipation rating (350 mW vs. 225 mW) provides additional thermal margin.

2SK209-GR(TE85L,F) is a secondary option for applications where higher drain current capability (14 mA) is acceptable. This Toshiba device offers a higher voltage rating (50 V) and is in active production with ROHS3 compliance. However, the significantly higher input capacitance (13 pF vs. 3 pF) and reduced maximum power rating (150 mW) may impact performance in high-frequency or power-sensitive applications.

2SK545-11D-TB-E shares the 40 V voltage rating and SOT-23-3 package with the MMBF4119 but exhibits lower drain current (60 µA) and reduced power dissipation (125 mW). This part is obsolete and should be considered only when active alternatives are unavailable.

Frequently Asked Questions (FAQ)

Q: Can the MMBFJ201 directly replace the MMBF4119 in all applications?

A: The MMBFJ201 is electrically compatible with the MMBF4119 for applications requiring 40 V breakdown voltage and N-Channel JFET operation in the SOT-23-3 package. Both devices share identical voltage ratings and comparable drain current specifications. The MMBFJ201's higher power rating (350 mW vs. 225 mW) provides additional design margin. Circuit validation is required to confirm performance in specific applications.

Q: What are the key differences between the MMBFJ201 and 2SK209-GR(TE85L,F)?

A: The MMBFJ201 maintains the 40 V voltage rating of the original MMBF4119, while the 2SK209-GR(TE85L,F) offers 50 V. The 2SK209 exhibits significantly higher drain current (14 mA vs. 200 µA) and input capacitance (13 pF vs. 3 pF), making it unsuitable for applications requiring low-current or high-frequency operation. Package compatibility differs: MMBFJ201 uses SOT-23-3, while 2SK209 uses SC-59.

Q: Are all substitute parts RoHS compliant?

A: The MMBFJ201 and 2SK209-GR(TE85L,F) are both ROHS3 compliant. The 2SK545-11D-TB-E is also ROHS3 compliant. The original MMBF4119 RoHS status is not specified in the available data.

Q: What is the impact of different input capacitance values on circuit performance?

A: Input capacitance (Ciss) affects high-frequency response and switching characteristics. The MMBF4119 specifies 3 pF at 10 V. The MMBFJ201 does not specify this parameter. The 2SK209-GR(TE85L,F) specifies 13 pF, which is significantly higher and may degrade high-frequency performance in sensitive applications such as RF amplifiers or fast-switching circuits.

Q: Why is the MMBF4119 classified as obsolete?

A: The MMBF4119 is listed as obsolete by the manufacturer. Active alternatives such as the MMBFJ201 are available for new designs and production continuity.

Q: Can the 2SK545-11D-TB-E be used as a substitute despite lower specifications?

A: The 2SK545-11D-TB-E is electrically compatible but exhibits reduced drain current (60 µA vs. 200 µA) and lower power dissipation (125 mW vs. 225 mW). This part is also obsolete. Use only when active alternatives are unavailable and application requirements permit reduced performance specifications.