IXFE44N50Q N-Channel 500V 39A MOSFET Equivalent & Substitute Parts

Part Overview

The IXFE44N50Q is an N-Channel 500V 39A MOSFET manufactured by IXYS in the HiPerFET™ Q Class series, housed in a SOT-227B chassis mount package. This device is classified as obsolete, necessitating identification of equivalent and substitute components for ongoing design requirements and production continuity. The part delivers 400W maximum power dissipation and operates across a temperature range of -40°C to 150°C (TJ). Due to its obsolete status, active alternative components with comparable electrical and mechanical specifications are required for new designs and replacement applications.

Key Parameters

Parameter	Value	Unit
FET Type	N-Channel	—
Drain to Source Voltage (Vdss)	500	V
Continuous Drain Current (Id) @ 25°C	39	A (Tc)
On-State Resistance (Rds On Max) @ Id, Vgs	120	mOhm @ 22A, 10V
Gate Threshold Voltage (Vgs(th) Max) @ Id	4	V @ 4mA
Power Dissipation (Max)	400	W (Tc)
Operating Temperature Range	-40 to 150	°C (TJ)
Mounting Type	Chassis Mount	—
Package Type	SOT-227B, miniBLOC	—
Product Status	Obsolete	—

Substitute Part Grouping Explanation

Substitution of the IXFE44N50Q is determined by strict alignment of the following critical parameters:

Primary Substitution Criteria:

Drain to Source Voltage (Vdss): 500V minimum
Continuous Drain Current (Id): 38A or greater at 25°C
On-State Resistance (Rds On): Comparable or lower values at specified gate voltage
Gate Threshold Voltage (Vgs(th)): Within acceptable operating range
Mounting Type: Chassis Mount configuration
Package Compatibility: SOT-227B or equivalent ISOTOP® form factor

Secondary Alignment Factors:

Power Dissipation capability: 357W or greater
Operating Temperature Range: Support for -40°C to 150°C or extended range
RoHS3 Compliance and REACH Unaffected status
Moisture Sensitivity Level (MSL): Level 1 (Unlimited)

The three substitute parts listed below meet these criteria with active product status and full compliance certifications.

Parameter Comparison

Parameter	IXFE44N50Q (Main)	APT38M50J	STE48NM50	STE53NC50
Manufacturer	IXYS	Microchip Technology	STMicroelectronics	STMicroelectronics
FET Type	N-Channel	N-Channel	N-Channel	N-Channel
Vdss (V)	500	500	550	500
Id @ 25°C (A)	39	38	48	53
Rds On (Max) @ Id, Vgs (mOhm)	120 @ 22A, 10V	100 @ 28A, 10V	100 @ 24A, 10V	80 @ 27A, 10V
Vgs(th) (Max) @ Id (V)	4 @ 4mA	5 @ 2.5mA	5 @ 250µA	4 @ 250µA
Gate Charge (Qg) @ 10V (nC)	190	220	117	434
Input Capacitance (Ciss) @ 25V (pF)	7000	8800	3700	11200
Power Dissipation (Max) (W)	400	357	450	460
Operating Temperature Range (°C)	-40 to 150	-55 to 150	to 150	to 150
Mounting Type	Chassis Mount	Chassis Mount	Chassis Mount	Chassis Mount
Package Type	SOT-227B, miniBLOC	ISOTOP®	ISOTOP®	ISOTOP®
Product Status	Obsolete	Active	Active	Active
RoHS3 Compliance	Compliant	Compliant	Compliant	Compliant
REACH Status	Unaffected	Unaffected	Unaffected	Unaffected
MSL Rating	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)

Engineering Selection Recommendations

APT38M50J (Microchip Technology)

The APT38M50J is an active substitute with 38A continuous drain current and 500V Vdss matching the primary voltage specification of the IXFE44N50Q. This device features improved on-state resistance of 100mOhm and extended operating temperature range (-55°C to 150°C). The ISOTOP® package provides equivalent thermal and mechanical performance to the SOT-227B form factor. RoHS3 compliance and REACH unaffected status ensure regulatory alignment. Power dissipation of 357W is within acceptable range for most applications. This part is recommended for direct substitution in designs where the lower current rating (38A vs. 39A) is acceptable.

STE48NM50 (STMicroelectronics)

The STE48NM50 offers 48A continuous drain current with elevated Vdss of 550V, providing enhanced voltage margin. On-state resistance of 100mOhm and superior gate charge characteristics (117nC) enable efficient switching performance. Power dissipation of 450W exceeds the original specification. The MDmesh™ series technology and ISOTOP® package deliver active product status with full compliance certifications. This part is suitable for applications requiring higher current capacity and voltage headroom.

STE53NC50 (STMicroelectronics)

The STE53NC50 delivers the highest current capacity at 53A with 500V Vdss, matching the original voltage specification exactly. Superior on-state resistance of 80mOhm provides lowest conduction losses. Power dissipation of 460W exceeds original requirements. The PowerMESH™ II series represents advanced technology with active product status. This part is recommended for applications prioritizing current capacity and efficiency, with consideration for higher input capacitance (11200pF) and gate charge (434nC) in switching circuit design.

All three substitute parts maintain chassis mount configuration, RoHS3 compliance, REACH unaffected status, and MSL Level 1 rating, ensuring compatibility with existing procurement and environmental requirements.

Frequently Asked Questions (FAQ)

Q: Can the APT38M50J replace the IXFE44N50Q in all applications?

A: The APT38M50J is electrically compatible for applications where 38A continuous drain current is sufficient. The 500V Vdss specification matches exactly. Verify that your circuit design does not require the additional 1A current margin of the original part. The ISOTOP® package provides equivalent thermal performance to SOT-227B.

Q: What is the primary difference between the three substitute options?

A: The three substitutes differ primarily in current capacity and on-state resistance. APT38M50J provides 38A at 100mOhm, STE48NM50 provides 48A at 100mOhm with 550V Vdss, and STE53NC50 provides 53A at 80mOhm with 500V Vdss. Select based on your circuit's current requirements and thermal design constraints.

Q: Are there package compatibility concerns between SOT-227B and ISOTOP®?

A: Both SOT-227B and ISOTOP® are chassis mount packages with equivalent form factors and thermal characteristics. Mechanical mounting and electrical connection compatibility should be verified against your specific PCB layout and heatsink design. Consult manufacturer datasheets for precise dimensional specifications.

Q: Does the higher gate charge of STE53NC50 affect circuit performance?

A: The STE53NC50 exhibits higher gate charge (434nC) compared to the original part (190nC). This requires evaluation of your gate driver circuit to ensure adequate current sourcing capability. Higher gate charge may increase switching losses in high-frequency applications. Verify gate driver specifications against the substitute part's requirements.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All three substitute parts (APT38M50J, STE48NM50, and STE53NC50) are RoHS3 compliant and REACH unaffected, matching the compliance status of the original IXFE44N50Q.

Q: Which substitute part offers the best thermal performance?

A: STE53NC50 and STE48NM50 both provide superior power dissipation (460W and 450W respectively) compared to the original 400W specification. STE53NC50 additionally features the lowest on-state resistance (80mOhm), resulting in reduced conduction losses and lower junction temperature under equivalent load conditions.

Q: Can I use STE48NM50 with its higher 550V Vdss rating in a 500V circuit?

A: Yes. The 550V Vdss rating of STE48NM50 provides additional voltage margin and is fully compatible with 500V circuit designs. The higher voltage rating does not create compatibility issues; it provides enhanced reliability under transient overvoltage conditions.

Q: What is the operating temperature range for each substitute?

A: APT38M50J operates from -55°C to 150°C (extended lower temperature range). STE48NM50 and STE53NC50 operate to 150°C maximum. The original IXFE44N50Q operates from -40°C to 150°C. Verify that your application's temperature requirements align with the selected substitute part.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message