FDFMA3N109 Equivalent & Substitute Parts

Part Overview

The FDFMA3N109 is an N-Channel MOSFET manufactured by onsemi, rated for 30V drain-to-source voltage with 2.9A continuous drain current. The device features a PowerTrench® series design in a 6-MicroFET (2x2) surface mount package with an integrated Schottky diode. This part is classified as obsolete, necessitating identification of active equivalent devices to maintain design continuity and ensure long-term component availability for new production and field replacements.

Substiute Parts

FDFMA3N109

onsemiIn Stock: 99580FDFMA3N109 Datasheet

Current PartRFQ

NTLJF4156NT1G

onsemiIn Stock: 23412NTLJF4156NT1G Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the FDFMA3N109 is determined by strict electrical and mechanical parameter compatibility within the N-Channel MOSFET category. The following parameters establish substitution validity:

Critical Matching Parameters:

• Drain-to-Source Voltage (Vdss): Must equal or exceed 30V
• FET Type: N-Channel only
• Technology: MOSFET (Metal Oxide)
• Integrated Schottky Diode: Required (Isolated configuration)
• Operating Temperature Range: Must support -55°C to 150°C
• Surface Mount Configuration: Required for PCB compatibility

Performance Parameters (Allowable Variance):

• Continuous Drain Current (Id): Substitute must support minimum 2.5A to maintain circuit functionality
• On-Resistance (Rds On): Lower values are acceptable; higher values require thermal analysis
• Gate Charge (Qg): Lower values reduce switching losses
• Power Dissipation: Substitute must handle thermal requirements of the application

The NTLJF4156NT1G meets all critical matching parameters and operates within acceptable performance variance for direct substitution.

Parameter Comparison

Engineering Selection Recommendations

The NTLJF4156NT1G is a direct substitute for the obsolete FDFMA3N109 based on the following engineering criteria:

Electrical Compatibility: The NTLJF4156NT1G maintains identical voltage ratings (30V Vdss) and supports the same operating temperature range (-55°C to 150°C). Both devices feature N-Channel MOSFET technology with integrated isolated Schottky diodes, ensuring functional equivalence in circuit applications.

Package Compatibility: Both devices use 6-pin surface mount packages with 2x2mm footprints (VDFN and WDFN variants). The exposed pad configuration is identical, permitting direct PCB layout reuse without modification.

Regulatory Compliance: The NTLJF4156NT1G carries ROHS3 compliance, REACH unaffected status, and MSL 1 rating, matching the original part's environmental and regulatory certifications.

Product Status: The NTLJF4156NT1G is classified as active, ensuring long-term availability and continued manufacturing support, addressing the obsolescence of the FDFMA3N109.

Performance Considerations: The substitute exhibits lower on-resistance (70 mOhm versus 123 mOhm) and reduced power dissipation (710 mW versus 1.5W), resulting in improved thermal efficiency. The continuous drain current rating of 2.5A is 86% of the original 2.9A specification. Applications operating at or below 2.5A continuous current experience no functional limitation. Applications requiring the full 2.9A rating must evaluate thermal and current distribution across multiple devices or alternative solutions.

Frequently Asked Questions (FAQ)

Q: Can the NTLJF4156NT1G directly replace the FDFMA3N109 on existing PCBs?

A: Yes. Both devices use compatible 6-pin surface mount packages with identical 2x2mm footprints and exposed pad configurations. No PCB layout modifications are required for physical placement and electrical connection.

Q: What is the primary difference in continuous drain current between these devices?

A: The FDFMA3N109 is rated for 2.9A continuous drain current, while the NTLJF4156NT1G is rated for 2.5A. The substitute supports 86% of the original current specification. Circuits operating below 2.5A continuous current experience no limitation. Circuits requiring the full 2.9A specification must evaluate alternative solutions or parallel device configurations.

Q: How do the on-resistance values affect circuit performance?

A: The NTLJF4156NT1G exhibits lower on-resistance (70 mOhm at 2A, 4.5V) compared to the FDFMA3N109 (123 mOhm at 2.9A, 4.5V). Lower on-resistance reduces conduction losses and heat generation, improving overall circuit efficiency. This characteristic is advantageous in power-sensitive applications.

Q: Are there differences in gate drive requirements?

A: The NTLJF4156NT1G has a lower gate threshold voltage (1.0V versus 1.5V) and higher gate charge (6.5 nC versus 3 nC). Gate drive circuits must supply sufficient voltage and charge to meet the substitute's specifications. Existing gate drive designs operating at 4.5V or higher accommodate the lower threshold voltage without modification.

Q: Do both devices support the same temperature range?

A: Yes. Both the FDFMA3N109 and NTLJF4156NT1G operate across -55°C to 150°C junction temperature, ensuring thermal compatibility across industrial and extended temperature applications.

Q: What is the significance of the Schottky diode feature?

A: Both devices integrate an isolated Schottky diode, providing body diode functionality for freewheeling current in switching applications. The isolated configuration allows independent control and biasing of the diode, enabling advanced circuit topologies.

Q: Are regulatory certifications identical between the two devices?

A: Yes. Both devices are ROHS3 compliant, REACH unaffected, and carry MSL 1 (unlimited moisture sensitivity level) ratings. Regulatory and environmental compliance requirements are satisfied by either device.

Q: Why is the FDFMA3N109 classified as obsolete?

A: The FDFMA3N109 is no longer in active production. The NTLJF4156NT1G represents onsemi's current-generation equivalent, offering improved performance characteristics and guaranteed long-term availability for new designs and field replacements.