MMBF4393 Equivalent & Substitute Parts

Part Overview

The MMBF4393 is an N-Channel JFET transistor manufactured by onsemi, housed in a SOT-23-3 surface mount package. This device is rated for 30 V drain-to-source voltage with 350 mW maximum power dissipation and operates across the temperature range of -55°C to 150°C. The MMBF4393 is classified as obsolete, making equivalent and substitute parts necessary for new designs and ongoing production requirements. Direct substitutes and similar alternatives are available from onsemi's active product portfolio, offering comparable or enhanced electrical characteristics within the same package family.

Substiute Parts

MMBF4393

onsemiIn Stock: 32019MMBF4393 Datasheet

Current PartRFQ

MMBF4393LT1G

onsemiIn Stock: 125465MMBF4393LT1G Datasheet

DirectRFQ

MMBF4393LT3G

onsemiIn Stock: 11187MMBF4393LT3G Datasheet

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CPH3910-TL-E

onsemiIn Stock: 17965CPH3910-TL-E Datasheet

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MMBF4391LT1G

onsemiIn Stock: 54550MMBF4391LT1G Datasheet

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MMBF4392LT1G

onsemiIn Stock: 242345MMBF4392LT1G Datasheet

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SMMBF4393LT1G

onsemiIn Stock: 45414SMMBF4393LT1G Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the MMBF4393 is determined by the following critical parameters: N-Channel FET type, 30 V Vdss rating, SOT-23-3 package compatibility, surface mount technology, and operating temperature range of -55°C to 150°C. All substitute parts listed maintain these core electrical and mechanical specifications.

Direct substitutes (MMBF4393LT1G and MMBF4393LT3G) are pin-compatible variants with identical base part numbers and electrical ratings, differing only in packaging format (Cut Tape & Digi-Reel versus Tape & Reel) and product status (Active versus Obsolete).

Similar substitutes (MMBF4391LT1G, MMBF4392LT1G, SMMBF4393LT1G, and CPH3910-TL-E) share the same package and voltage ratings but exhibit variations in drain current (Idss), gate-source cutoff voltage (VGS off), on-resistance (RDS(On)), and maximum power dissipation. These parts are functionally compatible within applications where the specific drain current and on-resistance characteristics are acceptable.

Parameter Comparison

Engineering Selection Recommendations

For applications requiring direct replacement of the MMBF4393 with minimal design modification, MMBF4393LT1G and MMBF4393LT3G are the primary choices. Both maintain identical electrical specifications and package compatibility. MMBF4393LT1G is available in Cut Tape & Digi-Reel packaging with 125,400 units in stock, while MMBF4393LT3G is supplied in the same format with 11,121 units available. Both are active products with ROHS3 compliance and unlimited moisture sensitivity level (MSL 1).

For applications where lower on-resistance is beneficial, MMBF4391LT1G offers 30 Ohms RDS(On) compared to the original 100 Ohms, with significantly higher drain current (50 mA @ 15 V). This part is suitable for switching applications requiring reduced conduction losses.

MMBF4392LT1G provides a mid-range alternative with 60 Ohms RDS(On) and 25 mA drain current, offering a balance between the original specification and the lower-resistance option.

SMMBF4393LT1G is qualified to AEC-Q101 automotive standards and is suitable for automotive and high-reliability applications requiring formal qualification documentation.

CPH3910-TL-E operates at a lower voltage rating (25 V Vdss) and exhibits different drain current and cutoff voltage characteristics. This part is suitable only for applications where the 25 V voltage rating is acceptable and the higher drain current (20 mA @ 5 V) and different cutoff voltage (1.8 V @ 100 µA) are compatible with circuit requirements.

Frequently Asked Questions (FAQ)

Q: Can MMBF4393LT1G directly replace MMBF4393 without circuit modification?

A: Yes. MMBF4393LT1G maintains identical electrical specifications (30 V Vdss, 5 mA Idss @ 15 V, 100 Ohms RDS(On), 225 mW power rating) and SOT-23-3 package compatibility. The primary difference is product status (Active versus Obsolete) and packaging format. Pin configuration and electrical behavior are equivalent.

Q: What is the difference between MMBF4393LT1G and MMBF4393LT3G?

A: Both parts are electrically identical with the same base part number (MMBF4393) and specifications. The difference is in packaging: MMBF4393LT1G is supplied in Cut Tape & Digi-Reel format with higher inventory (125,400 units), while MMBF4393LT3G is also Cut Tape & Digi-Reel with lower inventory (11,121 units). Both are active products.

Q: When should I use MMBF4391LT1G instead of MMBF4393LT1G?

A: MMBF4391LT1G is appropriate when lower on-resistance (30 Ohms versus 100 Ohms) reduces power dissipation in switching applications. However, it exhibits higher drain current (50 mA @ 15 V versus 5 mA @ 15 V) and higher gate-source cutoff voltage (4 V versus 500 mV). Circuit design must accommodate these parameter differences.

Q: Is CPH3910-TL-E compatible with MMBF4393 applications?

A: CPH3910-TL-E is not a direct substitute. It operates at 25 V Vdss (versus 30 V), has significantly different drain current characteristics (20 mA @ 5 V versus 5 mA @ 20 V), and exhibits different gate-source cutoff voltage (1.8 V @ 100 µA versus 500 mV @ 1 nA). Use only if circuit design explicitly accommodates these parameter variations and the 25 V voltage rating is sufficient.

Q: What is the significance of SMMBF4393LT1G's AEC-Q101 qualification?

A: AEC-Q101 qualification indicates the part meets automotive industry reliability and quality standards. SMMBF4393LT1G is suitable for automotive applications and high-reliability environments where formal qualification documentation is required. Electrical specifications are equivalent to MMBF4393LT1G.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All listed substitute parts (MMBF4393LT1G, MMBF4393LT3G, MMBF4391LT1G, MMBF4392LT1G, SMMBF4393LT1G, and CPH3910-TL-E) are ROHS3 compliant with MSL 1 (Unlimited) moisture sensitivity level.