MMBFJ310 Equivalent & Substitute Parts

Part Overview

The MMBFJ310 is an RF MOSFET JFET manufactured by onsemi, designed for RF applications requiring low-noise amplification at 450 MHz with 12 dB gain. The device is packaged in SOT-23-3 (TO-236-3) surface mount configuration and operates at 10 V test voltage with 10 mA test current. The MMBFJ310 is classified as obsolete, necessitating identification of active equivalent and substitute components for new designs and ongoing production requirements. Equivalent parts maintain identical or superior electrical performance within the same package footprint, while substitute parts offer functional alternatives with modified electrical characteristics suitable for specific application requirements.

Substiute Parts

MMBFJ310

onsemiIn Stock: 3535MMBFJ310 Datasheet

Current PartRFQ

MMBFJ309LT1G

onsemiIn Stock: 17826MMBFJ309LT1G Datasheet

DirectRFQ

SMMBFJ309LT1G

onsemiIn Stock: 24120SMMBFJ309LT1G Datasheet

DirectRFQ

SMMBFJ310LT3G

onsemiIn Stock: 26754SMMBFJ310LT3G Datasheet

DirectRFQ

2SK3557-6-TB-E

onsemiIn Stock: 482152SK3557-6-TB-E Datasheet

SimilarRFQ

2SK3557-7-TB-E

onsemiIn Stock: 65022SK3557-7-TB-E Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the MMBFJ310 is determined by alignment of the following critical parameters: package type (SOT-23-3), technology (JFET N-Channel), rated voltage (25 V), and surface mount configuration. Substitute parts are categorized into two groups based on electrical performance alignment:

Direct Equivalents (Active Status): Parts maintaining identical or superior gain (12 dB), voltage test rating (10 V), and current rating (60 mA) specifications. These components provide drop-in replacement capability with equivalent RF performance characteristics.

Functional Substitutes (Active Status): Parts with reduced current rating (30 mA) or unspecified frequency and gain parameters. These components are suitable for applications where the full performance envelope of the MMBFJ310 is not required, or where automotive-grade qualification (AEC-Q101) is mandated.

Similar Parts (Different Package/Voltage Class): Parts with alternative package designations (3-CP) or reduced voltage ratings (5 V test, 15 V rated) that share JFET N-Channel technology but operate in different electrical domains.

Parameter Comparison

Engineering Selection Recommendations

SMMBFJ310LT3G is the primary direct equivalent for MMBFJ310 replacement. This part maintains identical voltage test (10 V), current rating (60 mA), current test (10 mA), and gain (12 dB) specifications. SMMBFJ310LT3G is active in production status with AEC-Q101 automotive qualification and ROHS3 compliance. The part is available in Tape & Reel packaging with 26,700 units in stock inventory.

MMBFJ309LT1G serves as a functional substitute where reduced current rating (30 mA) is acceptable. This part is active in production with identical package and voltage specifications. MMBFJ309LT1G is available in Cut Tape & Digi-Reel packaging with 17,759 units in stock.

SMMBFJ309LT1G provides an automotive-qualified alternative with AEC-Q101 certification and reduced current rating (30 mA). This part is suitable for applications requiring automotive-grade components. Available in Tape & Reel packaging with 24,053 units in stock.

2SK3557-6-TB-E and 2SK3557-7-TB-E are similar parts with reduced voltage ratings (5 V test, 15 V rated) and alternative package designation (3-CP). These components are suitable only for applications operating within the 5 V test voltage envelope. Both parts are active in production with high inventory availability (48,200 and 6,400 units respectively).

Selection between direct equivalents and functional substitutes depends on application current requirements and automotive qualification mandates. All recommended parts maintain ROHS3 compliance and MSL 1 rating.

Frequently Asked Questions (FAQ)

Q: Can MMBFJ309LT1G directly replace MMBFJ310 in all applications?

A: MMBFJ309LT1G shares identical package (SOT-23-3), voltage rating (25 V), and technology (JFET N-Channel) with MMBFJ310. However, the current rating is reduced from 60 mA to 30 mA. Direct replacement is suitable only for applications where the circuit current requirement does not exceed 30 mA. Gain and frequency specifications are not provided for MMBFJ309LT1G, requiring circuit validation for RF performance.

Q: What is the difference between SMMBFJ310LT3G and MMBFJ310?

A: SMMBFJ310LT3G is the active production equivalent of the obsolete MMBFJ310. Both parts maintain identical electrical specifications: 10 V test voltage, 60 mA current rating, 10 mA test current, and 12 dB gain. SMMBFJ310LT3G includes AEC-Q101 automotive qualification and is supplied in Tape & Reel packaging, whereas MMBFJ310 was supplied in standard commercial packaging. Package footprint (SOT-23-3) is identical.

Q: Are SMMBFJ309LT1G and SMMBFJ310LT3G interchangeable?

A: SMMBFJ309LT1G and SMMBFJ310LT3G are not fully interchangeable. SMMBFJ310LT3G maintains the 60 mA current rating and 12 dB gain of the original MMBFJ310, while SMMBFJ309LT1G is rated for 30 mA maximum current with unspecified gain. Both parts share identical package (SOT-23-3), voltage rating (25 V), and AEC-Q101 qualification. Selection depends on circuit current and gain requirements.

Q: Why do 2SK3557-6-TB-E and 2SK3557-7-TB-E have lower voltage ratings?

A: The 2SK3557 series operates at 5 V test voltage with 15 V rated voltage, compared to MMBFJ310 specifications of 10 V test and 25 V rated. These parts are designed for lower-voltage RF applications and are not suitable for circuits requiring 10 V or higher test voltage operation. Package designation (3-CP) also differs from the standard SOT-23-3 footprint.

Q: What does AEC-Q101 qualification mean for automotive applications?

A: AEC-Q101 is an automotive industry qualification standard for discrete semiconductors. SMMBFJ309LT1G and SMMBFJ310LT3G carry this certification, indicating compliance with automotive reliability, temperature cycling, and quality requirements. MMBFJ309LT1G and the 2SK3557 series do not carry AEC-Q101 qualification and are not approved for automotive applications requiring this certification.

Q: Are all substitute parts ROHS3 compliant?

A: All parts listed (MMBFJ310, MMBFJ309LT1G, SMMBFJ309LT1G, SMMBFJ310LT3G, 2SK3557-6-TB-E, and 2SK3557-7-TB-E) are ROHS3 compliant. All parts also maintain MSL 1 (Unlimited) moisture sensitivity rating, indicating no special moisture handling requirements during storage or assembly.

Q: What packaging options are available for equivalent parts?

A: MMBFJ309LT1G is supplied in Cut Tape (CT) & Digi-Reel packaging. SMMBFJ309LT1G and SMMBFJ310LT3G are supplied in Tape & Reel (TR) packaging. The 2SK3557 series is supplied in Cut Tape (CT) & Digi-Reel packaging. All parts use identical SOT-23-3 (TO-236-3) surface mount package footprint, ensuring PCB compatibility regardless of packaging format.