STP4NK50Z Equivalent & Substitute Parts

Part Overview

The STP4NK50Z is an N-Channel MOSFET manufactured by STMicroelectronics, rated for 500V drain-to-source voltage with 3A continuous drain current in a TO-220 through-hole package. This device is part of the SuperMESH™ series and is classified as obsolete. Due to its obsolete status, equivalent substitute parts from active product lines are necessary to maintain design continuity and ensure long-term component availability for new production and field replacements.

Substiute Parts

STP4NK50Z

STMicroelectronicsIn Stock: 3892STP4NK50Z Datasheet

Current PartRFQ

IRF820APBF

Vishay SiliconixIn Stock: 10364IRF820APBF Datasheet

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IRF820LPBF

Vishay SiliconixIn Stock: 723IRF820LPBF Datasheet

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IRF820PBF

Vishay SiliconixIn Stock: 22943IRF820PBF Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the STP4NK50Z is determined by the following critical electrical and mechanical parameters:

Electrical Compatibility Criteria:

• Drain to Source Voltage (Vdss): 500V minimum
• FET Type: N-Channel
• Technology: MOSFET (Metal Oxide)
• Operating Temperature Range: -55°C to 150°C (TJ)
• Gate-Source Voltage (Vgs Max): ±20V or higher

Mechanical Compatibility Criteria:

• Mounting Type: Through Hole
• Package / Case: TO-220-3 or equivalent through-hole packages (TO-220AB, I2PAK/TO-262-3)

Performance Considerations:

• Continuous Drain Current (Id): Substitute parts rated at 2.5A meet the functional requirements for applications designed for the 3A STP4NK50Z
• On-Resistance (Rds On): Substitute parts with 3Ohm @ 1.5A, 10V are functionally equivalent to the 2.7Ohm specification
• Power Dissipation: Substitute parts rated at 50W (Tc) exceed the 45W requirement

All identified substitute parts meet the electrical and mechanical criteria for direct substitution in through-hole applications.

Parameter Comparison

Engineering Selection Recommendations

IRF820APBF and IRF820PBF (TO-220AB Package)

Both IRF820APBF and IRF820PBF are direct pin-compatible substitutes for the STP4NK50Z in TO-220 through-hole applications. These devices are manufactured by Vishay Siliconix and maintain active product status, ensuring long-term availability. Both parts are ROHS3 compliant and carry EAR99 classification. The IRF820PBF has higher inventory availability (22,899 pcs) compared to IRF820APBF (10,300 pcs). The continuous drain current rating of 2.5A is suitable for applications designed around the STP4NK50Z 3A specification. Power dissipation ratings of 50W exceed the original 45W requirement.

IRF820LPBF (I2PAK/TO-262-3 Package)

The IRF820LPBF provides electrical equivalence with a different through-hole package format (I2PAK/TO-262-3 Long Leads). This option is suitable for designs where PCB layout accommodates the I2PAK footprint. The device maintains the same electrical performance as IRF820APBF and IRF820PBF with identical Vdss, Id, and Rds On specifications. Inventory availability is lower (660 pcs) relative to the TO-220AB variants. Package selection should be based on PCB design requirements and mechanical constraints.

All three substitute parts are ROHS3 compliant and carry identical ECCN and HTSUS classifications as the original STP4NK50Z, supporting regulatory compliance requirements.

Frequently Asked Questions (FAQ)

Q: Can IRF820APBF, IRF820PBF, and IRF820LPBF be used interchangeably with STP4NK50Z?

A: IRF820APBF and IRF820PBF are pin-compatible direct substitutes for TO-220 applications. IRF820LPBF is electrically equivalent but uses the I2PAK package format, requiring PCB layout modifications. All three meet the electrical specifications for substitution.

Q: What is the difference between IRF820APBF and IRF820PBF?

A: Both devices are electrically identical with 500V Vdss, 2.5A continuous drain current, and 3Ohm Rds On. The primary difference is inventory availability and packaging designation. IRF820PBF has significantly higher stock (22,899 pcs vs. 10,300 pcs).

Q: Why is the continuous drain current lower on substitute parts (2.5A vs. 3A)?

A: The 2.5A rating on Vishay Siliconix IRF820 devices is sufficient for applications designed for the STP4NK50Z. The lower rating reflects different thermal and electrical characterization methodologies between manufacturers. Designs operating below 2.5A continuous current experience no functional limitation.

Q: Is the I2PAK package (IRF820LPBF) compatible with TO-220 PCB layouts?

A: No. The I2PAK package uses a different footprint (TO-262-3 Long Leads) than the TO-220-3 format. PCB redesign is required for IRF820LPBF implementation. IRF820APBF and IRF820PBF maintain TO-220-3 compatibility with existing layouts.

Q: Are all substitute parts RoHS compliant?

A: Yes. IRF820APBF, IRF820PBF, and IRF820LPBF are all ROHS3 compliant, matching the compliance status of the STP4NK50Z.

Q: What is the impact of higher gate charge (Qg) on substitute parts?

A: IRF820APBF has 17nC gate charge compared to STP4NK50Z at 12nC. IRF820PBF and IRF820LPBF have 24nC. Higher gate charge increases driver power dissipation and switching time. Applications with high-frequency switching or current-limited gate drivers require evaluation of gate drive capability.

Q: Can the STP4NK50Z be replaced in existing inventory?

A: Yes. Due to the obsolete status of STP4NK50Z, substitution with active-status IRF820 variants is appropriate for new production and field replacements. Electrical and mechanical compatibility is established across all three substitute options.