MMBF5484LT1G Equivalent & Substitute Parts

Part Overview

The MMBF5484LT1G is an N-Channel JFET transistor manufactured by onsemi, housed in a SOT-23-3 surface mount package. This device is rated for 25 V breakdown voltage and 225 mW maximum power dissipation, with an operating temperature range of -55°C to 150°C. The part is currently listed as obsolete, making substitute parts necessary for new designs and ongoing production requirements. Equivalent and substitute parts must maintain compatibility with the SOT-23-3 package footprint and support the same electrical operating parameters.

Substiute Parts

MMBF5484LT1G

onsemiIn Stock: 5444MMBF5484LT1G Datasheet

Current PartRFQ

MMBF5457

onsemiIn Stock: 35508MMBF5457 Datasheet

DirectRFQ

MMBF5484

onsemiIn Stock: 19348MMBF5484 Datasheet

DirectRFQ

MMBF5485

onsemiIn Stock: 65234MMBF5485 Datasheet

DirectRFQ

MMBF5486

onsemiIn Stock: 3600MMBF5486 Datasheet

DirectRFQ

MMBFJ108

onsemiIn Stock: 1197MMBFJ108 Datasheet

DirectRFQ

MMBFJ110

onsemiIn Stock: 1718MMBFJ110 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the MMBF5484LT1G are selected based on strict electrical and mechanical compatibility criteria. The primary substitution parameters are:

• FET Type & Configuration: N-Channel JFET technology
• Package Compatibility: SOT-23-3 surface mount package (TO-236-3, SC-59)
• Voltage Rating: Minimum 25 V breakdown voltage (V(BR)GSS)
• Operating Temperature Range: Support for -55°C to 150°C junction temperature
• Mounting Type: Surface mount technology
• Compliance & Status: Active product status with RoHS3 compliance preferred for new designs

Substitute parts are grouped into two categories:

Category A - Direct Electrical Equivalents (Same Idss Range) Parts with drain current (Idss) specifications matching or closely aligned to the original 1 mA @ 15 V specification: MMBF5457, MMBF5484, MMBF5485, MMBF5486.

Category B - Alternative JFET Devices (Different Idss Specifications) Parts with different drain current characteristics but maintaining N-Channel JFET configuration and SOT-23-3 packaging: MMBFJ108, MMBFJ110.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Preferred)

MMBF5457 is the primary recommended substitute. It maintains the same 25 V breakdown voltage and 1 mA drain current specification as the original MMBF5484LT1G, ensuring electrical compatibility in existing circuit designs. MMBF5457 is active in production with RoHS3 compliance and unlimited moisture sensitivity rating (MSL 1). Higher power dissipation (350 mW vs. 225 mW) provides additional thermal margin.

For Higher Current Applications

MMBF5484, MMBF5485, and MMBF5486 are active alternatives with increased drain current ratings (5 mA, 10 mA, and 20 mA respectively) and higher power handling (400 mW). These parts are suitable when circuit requirements demand higher current capacity while maintaining the SOT-23-3 package and 25 V rating.

For Alternative Specifications

MMBFJ108 and MMBFJ110 offer different drain current and cutoff voltage characteristics. MMBFJ108 provides 80 mA drain current with 8 Ohm on-resistance, while MMBFJ110 delivers 10 mA with 18 Ohm on-resistance. These parts are appropriate only when circuit design specifically requires their distinct electrical parameters.

Compliance Considerations

All recommended substitute parts carry RoHS3 compliance and REACH unaffected status, meeting modern environmental and regulatory requirements. MSL 1 (unlimited) rating applies to all candidates, eliminating moisture sensitivity concerns during storage and assembly.

Frequently Asked Questions (FAQ)

Q: Can MMBF5457 directly replace MMBF5484LT1G in existing designs?

A: Yes. MMBF5457 maintains identical voltage rating (25 V), drain current specification (1 mA @ 15 V), and SOT-23-3 package footprint. The higher power rating (350 mW vs. 225 mW) is backward compatible. No circuit modifications are required.

Q: What is the difference between MMBF5484, MMBF5485, and MMBF5486?

A: These three parts differ in drain current rating: MMBF5484 at 5 mA, MMBF5485 at 10 mA, and MMBF5486 at 20 mA. All share the same 25 V breakdown voltage, 400 mW power rating, and SOT-23-3 package. Selection depends on circuit current requirements.

Q: Are MMBFJ108 and MMBFJ110 suitable replacements?

A: These parts are not direct replacements. MMBFJ108 has significantly higher drain current (80 mA) and different cutoff voltage (3 V), while MMBFJ110 has 10 mA drain current with 4 V cutoff. Use only if circuit design specifically requires these electrical characteristics.

Q: What packaging options are available for substitute parts?

A: All substitute parts are available in SOT-23-3 surface mount package. MMBF5457 is supplied in Cut Tape (CT) and Digi-Reel format. MMBF5485, MMBF5486, and MMBFJ110 are available in Tape & Reel (TR) format. MMBFJ108 is supplied in Cut Tape (CT) and Digi-Reel format.

Q: Do all substitute parts support the same operating temperature range?

A: Yes. All substitute parts support -55°C to 150°C junction temperature operation, matching the original MMBF5484LT1G specification.

Q: What is the inventory status of substitute parts?

A: MMBF5457 has the highest availability (35,400 pcs). MMBF5485 (65,200 pcs) and MMBF5484 (19,275 pcs) also have substantial stock. MMBFJ108 (1,106 pcs) and MMBFJ110 (1,616 pcs) have limited availability. MMBF5486 (3,565 pcs) has moderate stock levels.