STP4NK50ZFP N-Channel 500V 3A MOSFET Equivalent & Substitute Parts

Part Overview

The STP4NK50ZFP is an N-Channel 500V 3A MOSFET manufactured by STMicroelectronics in the SuperMESH™ series, housed in a TO-220FP through-hole package. This device is classified as obsolete, necessitating identification of active equivalent and substitute components for ongoing design requirements and production continuity. The part delivers 20W maximum power dissipation and operates across a temperature range of -55°C to 150°C.

Key Parameters

Parameter	Value	Unit
Drain to Source Voltage (Vdss)	500	V
Continuous Drain Current (Id) @ 25°C	3	A
On-State Resistance (Rds On) @ 1.5A, 10V	2.7	Ω
Gate Threshold Voltage (Vgs(th)) @ 50µA	4.5	V
Gate Charge (Qg) @ 10V	12	nC
Input Capacitance (Ciss) @ 25V	310	pF
Power Dissipation (Max)	20	W
Operating Temperature Range	-55 to 150	°C
Package Type	TO-220-3	Through Hole

Substitute Part Grouping Explanation

Substitution of the STP4NK50ZFP is determined by the following critical electrical and mechanical parameters:

Primary Matching Criteria:

Drain to Source Voltage (Vdss): 500V minimum
FET Type: N-Channel
Technology: MOSFET (Metal Oxide)
Mounting Type: Through Hole
Package Family: TO-220-3

Secondary Compatibility Factors:

Continuous Drain Current (Id): Equal to or greater than 3A
On-State Resistance (Rds On): Lower values indicate improved performance
Gate Threshold Voltage (Vgs(th)): Within acceptable operating range
Operating Temperature Range: -55°C to 150°C minimum
Power Dissipation: Equal to or greater than 20W

The substitute parts identified below meet or exceed the primary matching criteria and maintain electrical compatibility within the specified operating parameters. Variations in secondary parameters reflect different device optimization approaches while maintaining functional equivalence for the 500V, 3A application class.

Parameter Comparison

Parameter	STP4NK50ZFP	FQPF5N50CYDTU	IRFI820GPBF	IRFI830GPBF
Manufacturer	STMicroelectronics	Fairchild Semiconductor	Vishay Siliconix	Vishay Siliconix
Product Status	Obsolete	Active	Active	Active
Vdss (V)	500	500	500	500
Id @ 25°C (A)	3	5	2.1	3.1
Rds On @ 10V (Ω)	2.7 @ 1.5A	1.4 @ 2.5A	3 @ 1.3A	1.5 @ 1.9A
Vgs(th) (V)	4.5 @ 50µA	4 @ 250µA	4 @ 250µA	4 @ 250µA
Gate Charge Qg (nC)	12 @ 10V	24 @ 10V	24 @ 10V	38 @ 10V
Ciss (pF)	310 @ 25V	625 @ 25V	360 @ 25V	610 @ 25V
Power Dissipation (W)	20	38	30	35
Operating Temperature (°C)	-55 to 150	-55 to 150	-55 to 150	-55 to 150
Package	TO-220FP	TO-220F-3 (Y-Forming)	TO-220-3	TO-220-3
RoHS Status	ROHS3 Compliant	Not specified	ROHS3 Compliant	ROHS3 Compliant

Engineering Selection Recommendations

FQPF5N50CYDTU (Fairchild Semiconductor)

This device provides the highest current rating (5A) and lowest on-state resistance (1.4Ω) among the substitute options. The 38W power dissipation capability exceeds the original part specification. The TO-220F-3 package with Y-forming leads offers mechanical compatibility with standard TO-220-3 footprints. Product status is active with full availability. RoHS compliance status is not specified in available documentation.

IRFI820GPBF (Vishay Siliconix)

This part operates at 2.1A continuous drain current, below the original 3A specification. The 3Ω on-state resistance is higher than the STP4NK50ZFP. The 30W power dissipation provides adequate margin. ROHS3 compliance is confirmed. Product status is active with high inventory availability (16,380 units). The TO-220-3 isolated tab package is mechanically compatible. This device is suitable for applications where the 2.1A rating is sufficient.

IRFI830GPBF (Vishay Siliconix)

This device most closely matches the original part specifications with 3.1A continuous drain current and 1.5Ω on-state resistance, providing superior performance characteristics. The 35W power dissipation exceeds the original 20W specification. ROHS3 compliance is confirmed. Product status is active with moderate inventory (1,542 units). The TO-220-3 isolated tab package is mechanically compatible. This part is the preferred substitute for direct replacement applications.

Frequently Asked Questions (FAQ)

Q: Can the IRFI820GPBF replace the STP4NK50ZFP in all applications?

A: The IRFI820GPBF operates at 2.1A continuous drain current, which is below the original 3A specification. This device is suitable only for applications where the actual operating current does not exceed 2.1A. For applications requiring the full 3A capability, the IRFI830GPBF is the appropriate substitute.

Q: What is the difference between IRFI820GPBF and IRFI820G?

A: Both devices share identical electrical specifications (500V, 2.1A, 3Ω Rds On). The primary difference is packaging: IRFI820GPBF is supplied in tube packaging, while IRFI820G is supplied in bulk packaging. IRFI820GPBF carries ROHS3 compliance certification, whereas IRFI820G is RoHS non-compliant. For new designs, IRFI820GPBF is the preferred option.

Q: Are the TO-220FP and TO-220-3 packages mechanically interchangeable?

A: The TO-220FP (full pack) and TO-220-3 packages are mechanically compatible for through-hole mounting applications. Both feature three leads and standard TO-220 footprint dimensions. The FQPF5N50CYDTU uses TO-220F-3 with Y-forming leads, which is also compatible with standard TO-220-3 PCB layouts.

Q: How do gate charge differences affect circuit performance?

A: The STP4NK50ZFP has a gate charge of 12nC, while substitute parts range from 24nC to 38nC. Higher gate charge requires longer switching times and increased driver current capability. For applications with fast switching requirements or limited gate drive current, the lower gate charge of the original part may be advantageous. Circuit redesign or gate driver adjustment may be necessary when substituting with higher gate charge devices.

Q: Which substitute part has the lowest on-state resistance?

A: The FQPF5N50CYDTU has the lowest on-state resistance at 1.4Ω (measured at 2.5A, 10V). The IRFI830GPBF follows at 1.5Ω (measured at 1.9A, 10V). Lower on-state resistance reduces conduction losses and heat generation, improving overall circuit efficiency.

Q: Is RoHS compliance a critical factor for part selection?

A: RoHS compliance is determined by application requirements and regulatory jurisdiction. The IRFI830GPBF and IRFI820GPBF both carry ROHS3 compliance certification. The FQPF5N50CYDTU RoHS status is not specified in available documentation. For applications subject to RoHS regulations, IRFI830GPBF or IRFI820GPBF are the appropriate selections.

Q: What is the impact of higher input capacitance on circuit design?

A: Input capacitance (Ciss) ranges from 310pF in the original part to 625pF in the FQPF5N50CYDTU. Higher input capacitance increases the capacitive load on the gate driver circuit, potentially requiring higher driver current or slower switching speeds. For high-frequency switching applications, lower input capacitance is preferable.

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