FDG329N N-Channel MOSFET 20V 1.5A Equivalent & Substitute Parts

Part Overview

The FDG329N is an N-Channel MOSFET manufactured by onsemi, rated for 20V drain-to-source voltage with 1.5A continuous drain current at 25°C. The device is housed in a 6-TSSOP (SC-88/SOT-363) surface mount package and features a maximum power dissipation of 420mW. The FDG329N is classified as obsolete, necessitating identification of active equivalent parts for new designs and ongoing production requirements. Substitute parts must maintain electrical compatibility across critical parameters including voltage rating, current capacity, and thermal characteristics while supporting the same surface mount packaging.

Substiute Parts

FDG329N

onsemiIn Stock: 35175FDG329N Datasheet

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NTJS3157NT1G

onsemiIn Stock: 1647NTJS3157NT1G Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the FDG329N are selected based on strict electrical and mechanical compatibility criteria. The primary substitution logic is based on the following parameters:

Voltage Rating Compatibility: Substitute parts must maintain the same or higher Drain to Source Voltage (Vdss) rating of 20V to ensure safe operation in existing circuit designs.

Current Capacity: Substitute parts must support the required continuous drain current. Parts with equal or greater current ratings are acceptable, as they provide equivalent or enhanced current handling capability.

Package Compatibility: All substitute parts must use the same surface mount package designation (6-TSSOP, SC-88, SOT-363) to ensure mechanical and electrical compatibility with existing PCB layouts.

Thermal Characteristics: Operating temperature range must span the required -55°C to 150°C (TJ) specification to maintain functional performance across the full operating envelope.

On-Resistance (Rds On): The maximum on-resistance specification determines switching losses and thermal performance. Substitute parts with equal or lower Rds On values are acceptable.

Gate Threshold Voltage (Vgs(th)): This parameter must be compatible with existing gate drive circuitry. Substitute parts with threshold voltages within the specified range ensure proper gate control.

Parameter Comparison

Engineering Selection Recommendations

The NTJS3157NT1G is a direct substitute for the obsolete FDG329N based on the following engineering criteria:

Electrical Compatibility: Both devices share identical Drain to Source Voltage (Vdss) ratings of 20V and identical operating temperature ranges (-55°C to 150°C TJ). The NTJS3157NT1G provides enhanced current capacity (3.2A versus 1.5A), lower on-resistance (60 mOhm versus 90 mOhm at 4.5V Vgs), and increased power dissipation capability (1W versus 420mW), making it suitable for applications requiring the FDG329N's performance envelope.

Package Compatibility: Both parts utilize the identical 6-TSSOP (SC-88, SOT-363) surface mount package, ensuring direct PCB layout compatibility without redesign.

Product Status and Compliance: The NTJS3157NT1G is classified as Active, providing long-term availability and supply chain stability. Both parts maintain REACH Unaffected status and Moisture Sensitivity Level 1 (Unlimited), ensuring compliance with environmental and handling requirements.

Gate Drive Considerations: The NTJS3157NT1G exhibits a lower gate threshold voltage (1.0V versus 1.5V at 250µA), which may require evaluation in gate drive circuits designed for the FDG329N. The increased gate charge (15 nC versus 4.6 nC) and input capacitance (500 pF versus 324 pF) indicate slightly higher gate drive requirements.

Frequently Asked Questions (FAQ)

Q: Can the NTJS3157NT1G directly replace the FDG329N in existing designs?

A: The NTJS3157NT1G is electrically and mechanically compatible with the FDG329N. Both devices share the same 20V Vdss rating, identical operating temperature range, and identical 6-TSSOP (SC-88, SOT-363) package. The NTJS3157NT1G provides enhanced performance specifications (higher current capacity, lower on-resistance, and greater power dissipation capability), making it suitable for direct substitution in applications designed for the FDG329N.

Q: What are the key differences between these two parts?

A: The primary differences are continuous drain current (1.5A for FDG329N versus 3.2A for NTJS3157NT1G), on-resistance (90 mOhm versus 60 mOhm at 4.5V Vgs), power dissipation (420mW versus 1W), gate threshold voltage (1.5V versus 1.0V at 250µA), gate charge (4.6 nC versus 15 nC), and input capacitance (324 pF versus 500 pF). The NTJS3157NT1G is an active product, while the FDG329N is obsolete.

Q: Are there any gate drive circuit considerations when substituting the NTJS3157NT1G for the FDG329N?

A: The NTJS3157NT1G exhibits a lower gate threshold voltage (1.0V versus 1.5V) and higher gate charge (15 nC versus 4.6 nC). Gate drive circuits designed for the FDG329N must be evaluated to confirm adequate drive voltage and current capability for the NTJS3157NT1G. The increased input capacitance (500 pF versus 324 pF) may also affect switching speed in high-frequency applications.

Q: Do both parts share the same package footprint?

A: Yes. Both the FDG329N and NTJS3157NT1G use the 6-TSSOP (SC-88, SOT-363) surface mount package, ensuring identical PCB footprints and mechanical compatibility without layout modifications.

Q: What is the product status difference between these parts?

A: The FDG329N is classified as Obsolete, indicating discontinued production and limited availability. The NTJS3157NT1G is classified as Active, ensuring ongoing production, long-term availability, and supply chain continuity for new designs and production requirements.

Q: Are both parts compliant with environmental and regulatory requirements?

A: Yes. Both the FDG329N and NTJS3157NT1G maintain REACH Unaffected status, Moisture Sensitivity Level 1 (Unlimited), and identical ECCN (EAR99) classifications. The NTJS3157NT1G additionally carries RoHS3 Compliance certification.