FA38SA50LC N-Channel 500V 38A MOSFET Equivalent & Substitute Parts

Part Overview

The FA38SA50LC is an N-Channel 500V 38A MOSFET manufactured by Vishay General Semiconductor - Diodes Division in the HEXFET® series. This device is rated for 500W power dissipation and features a SOT-227 chassis mount package. The part is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement.

Substitute parts must maintain compatibility across critical electrical parameters including drain-source voltage rating, continuous drain current capability, gate charge characteristics, and thermal performance specifications. All substitute devices listed are active products from current manufacturers, ensuring long-term availability and supply chain continuity.

Key Parameters

Parameter	FA38SA50LC	Unit
Drain to Source Voltage (Vdss)	500	V
Continuous Drain Current (Id) @ 25°C	38	A (Tc)
Rds On (Max) @ Id, Vgs	130 mOhm @ 23A, 10V	mOhm
Gate Charge (Qg) (Max) @ Vgs	420 nC @ 10V	nC
Vgs(th) (Max) @ Id	4 V @ 250µA	V
Power Dissipation (Max)	500	W (Tc)
Operating Temperature Range	-55 to 150	°C (TJ)
Package Type	SOT-227	-
Mounting Type	Chassis Mount	-
Product Status	Obsolete	-

Substitute Part Grouping Explanation

Substitution eligibility for the FA38SA50LC is determined by the following critical parameters:

Mandatory Matching Criteria:

Drain to Source Voltage (Vdss): 500V minimum
N-Channel FET technology with MOSFET architecture
Chassis mount configuration
Operating temperature range: -55°C to 150°C minimum
Gate drive voltage: 10V nominal

Performance Compatibility Criteria:

Continuous drain current (Id): 38A or greater at 25°C
Gate charge (Qg): Acceptable within application switching frequency constraints
Rds On: Lower or equivalent on-state resistance
Power dissipation capability: Sufficient thermal performance for target application

All four substitute parts meet the mandatory matching criteria and provide equivalent or superior electrical performance. Substitutes are grouped by their electrical characteristics and package configurations, with variations in gate charge, input capacitance, and power dissipation reflecting different semiconductor process technologies and thermal management approaches.

Parameter Comparison

Parameter	FA38SA50LC (Vishay)	APT38M50J (Microchip)	APT5010JLLU3 (Microchip)	IXTN60N50L2 (IXYS)	STE53NC50 (STMicroelectronics)	Unit
Drain to Source Voltage (Vdss)	500	500	500	500	500	V
Continuous Drain Current (Id) @ 25°C	38	38	41	53	53	A (Tc)
Rds On (Max) @ Id, Vgs	130 @ 23A, 10V	100 @ 28A, 10V	100 @ 23A, 10V	100 @ 30A, 10V	80 @ 27A, 10V	mOhm
Gate Charge (Qg) (Max) @ Vgs	420 @ 10V	220 @ 10V	96 @ 10V	610 @ 10V	434 @ 10V	nC
Vgs(th) (Max) @ Id	4 @ 250µA	5 @ 2.5mA	5 @ 2.5mA	4.5 @ 250µA	4 @ 250µA	V
Vgs (Max)	±20	±30	±30	±30	±30	V
Input Capacitance (Ciss) (Max) @ Vds	6900 @ 25V	8800 @ 25V	4360 @ 25V	24000 @ 25V	11200 @ 25V	pF
Power Dissipation (Max)	500	357	378	735	460	W (Tc)
Operating Temperature Range	-55 to 150	-55 to 150	-55 to 150	-55 to 150	-55 to 150	°C (TJ)
Package Type	SOT-227	ISOTOP®	SOT-227	SOT-227B	ISOTOP®	-
Mounting Type	Chassis Mount	Chassis Mount	Chassis Mount	Chassis Mount	Chassis Mount	-
RoHS Status	Non-compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	-
Product Status	Obsolete	Active	Active	Active	Active	-

Engineering Selection Recommendations

APT38M50J (Microchip Technology)

The APT38M50J provides direct current and voltage equivalence to the FA38SA50LC with matched 38A continuous drain current at 500V. This part features improved on-state resistance (100 mOhm versus 130 mOhm) and reduced gate charge (220 nC versus 420 nC), resulting in lower switching losses and improved thermal efficiency. The ISOTOP® package offers enhanced thermal performance compared to the original SOT-227 configuration. RoHS3 compliance and active product status ensure long-term availability. Power dissipation is rated at 357W, which is lower than the original part; thermal analysis is required for applications demanding the full 500W capability.

APT5010JLLU3 (Microchip Technology)

The APT5010JLLU3 exceeds the FA38SA50LC specifications with 41A continuous drain current and maintains 500V voltage rating. This device delivers the lowest gate charge (96 nC) among all substitutes, enabling faster switching operation and reduced driver power requirements. Input capacitance is also minimized at 4360 pF, supporting high-frequency applications. RoHS3 compliance and active status provide supply chain security. Power dissipation is 378W; applications requiring maximum thermal headroom should evaluate the IXTN60N50L2 alternative.

IXTN60N50L2 (IXYS)

The IXTN60N50L2 represents the highest current-rated option at 53A continuous drain current, providing 39% margin above the original 38A specification. This device delivers the highest power dissipation rating (735W), supporting demanding thermal applications. The SOT-227B package maintains mechanical compatibility with the original SOT-227 configuration. Gate charge is elevated at 610 nC, requiring consideration in high-frequency switching designs. RoHS3 compliance and extensive inventory (68,656 units) ensure immediate availability. Input capacitance is significantly higher at 24,000 pF, which may impact gate drive circuit design.

STE53NC50 (STMicroelectronics)

The STE53NC50 provides 53A continuous drain current with the lowest on-state resistance (80 mOhm) across all substitutes, minimizing conduction losses. This device combines high current capability with improved efficiency characteristics. The ISOTOP® package offers thermal advantages over standard SOT-227 configurations. RoHS3 compliance and active product status support modern supply chains. Power dissipation is rated at 460W; applications requiring the full 500W thermal budget should evaluate the IXTN60N50L2. Gate charge of 434 nC is moderate among the substitute options.

Selection Criteria Summary:

Direct replacement with improved efficiency: APT38M50J
Lowest gate charge for high-frequency switching: APT5010JLLU3
Maximum thermal capability: IXTN60N50L2
Lowest on-state resistance: STE53NC50

All substitutes are RoHS3 compliant active products, eliminating the obsolescence risk of the original FA38SA50LC. Package type selection (SOT-227 versus ISOTOP®) depends on thermal management requirements and PCB layout constraints.

Frequently Asked Questions (FAQ)

Q: Can the APT38M50J directly replace the FA38SA50LC without circuit modifications?

A: The APT38M50J provides electrical equivalence in voltage rating (500V) and current rating (38A). The ISOTOP® package differs from the original SOT-227, requiring PCB layout verification for thermal interface compatibility. Gate charge reduction (220 nC versus 420 nC) may improve switching performance but does not prevent direct substitution. Verify thermal management capability, as power dissipation is rated at 357W versus the original 500W.

Q: What is the impact of higher gate charge in the IXTN60N50L2?

A: Gate charge of 610 nC (versus 420 nC in the original) increases the charge that must be supplied by the gate driver circuit. This results in higher gate drive power consumption and potentially longer switching transition times. Applications operating at high switching frequencies (above 50 kHz) should evaluate the APT5010JLLU3 with its 96 nC gate charge for reduced driver stress and improved efficiency.

Q: Are all substitute parts RoHS compliant?

A: Yes. All four substitute parts carry RoHS3 compliance certification. The original FA38SA50LC is RoHS non-compliant. Designs requiring RoHS compliance must transition to one of the substitute parts.

Q: Which substitute offers the best thermal performance?

A: The IXTN60N50L2 provides the highest power dissipation rating at 735W, supporting the most demanding thermal applications. The STE53NC50 offers the lowest on-state resistance (80 mOhm), minimizing conduction losses and heat generation. Selection depends on whether the application is limited by dissipation capability or conduction efficiency.

Q: Can I use the higher-current substitutes (53A) in place of the 38A original?

A: Yes. The IXTN60N50L2 and STE53NC50 both provide 53A continuous drain current, exceeding the original 38A specification. These devices are electrically compatible and provide design margin. Verify that gate drive circuits can accommodate the higher gate charge (434-610 nC) and that PCB thermal management is adequate for the selected package type.

Q: What is the difference between SOT-227 and ISOTOP® packages?

A: Both are chassis mount configurations for 500V MOSFETs. SOT-227 is a standard surface-mount package used in the original FA38SA50LC and APT5010JLLU3. ISOTOP® is a specialized package used in APT38M50J and STE53NC50 that provides enhanced thermal performance through improved die-to-case interface design. Package selection depends on PCB layout constraints and thermal management requirements.

Q: Is the APT5010JLLU3 suitable for high-frequency applications?

A: Yes. The APT5010JLLU3 features the lowest gate charge (96 nC) and lowest input capacitance (4360 pF) among all substitutes, making it optimal for high-frequency switching applications above 50 kHz. The reduced capacitive and charge requirements minimize gate driver stress and improve overall system efficiency.

Q: What inventory considerations should I evaluate?

A: The IXTN60N50L2 has the highest inventory availability at 68,656 units, ensuring immediate procurement. The STE53NC50 has 3,500 units in stock. The Microchip parts (APT38M50J with 834 units and APT5010JLLU3 with 1,040 units) have lower inventory levels. For long-term production, verify supplier lead times and allocation policies.

Q: Are all substitutes available in the same packaging options?

A: No. The APT38M50J and STE53NC50 are supplied in Tube packaging, while the APT5010JLLU3 is supplied in Bulk packaging, and the IXTN60N50L2 is supplied in Tube packaging. Verify packaging compatibility with your procurement and assembly processes.

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