FQP4N20 N-Channel MOSFET Equivalent & Substitute Parts

Part Overview

The FQP4N20 is an N-Channel MOSFET manufactured by onsemi, rated for 200V drain-to-source voltage with 3.6A continuous drain current at 25°C. This device is packaged in a Through Hole TO-220-3 configuration and is part of the QFET® series. The FQP4N20 is classified as obsolete, making identification of equivalent and substitute parts essential for ongoing design support and component procurement.

Substitute parts are necessary to maintain design continuity, ensure supply chain availability, and support legacy system maintenance where the original FQP4N20 is no longer readily available from primary sources.

Key Parameters

Parameter	Value	Unit
Drain to Source Voltage (Vdss)	200	V
Continuous Drain Current (Id) @ 25°C	3.6	A
Rds On (Max) @ Id, Vgs	1.4	Ohm @ 1.8A, 10V
Gate Threshold Voltage Vgs(th) (Max) @ Id	5	V @ 250µA
Gate Charge (Qg) (Max) @ Vgs	6.5	nC @ 10V
Input Capacitance (Ciss) (Max) @ Vds	220	pF @ 25V
Power Dissipation (Max)	45	W
Operating Temperature Range	-55 to 150	°C
Package Type	TO-220-3	Through Hole
FET Type	N-Channel
Technology	MOSFET (Metal Oxide)

Substitute Part Grouping Explanation

Substitution of the FQP4N20 is determined by the following critical parameters:

Primary Substitution Criteria:

FET Type: N-Channel configuration
Technology: MOSFET (Metal Oxide Semiconductor)
Package Type: TO-220-3 Through Hole mounting
Drain to Source Voltage (Vdss): Minimum 200V or higher
Continuous Drain Current (Id): Minimum 3.6A or higher at 25°C
Gate Drive Voltage: 10V maximum Rds On specification
Operating Temperature Range: Support for -55°C to 150°C or equivalent

Substitution Logic: Substitute parts must maintain electrical compatibility within the FQP4N20's application envelope. Parts with higher Vdss ratings, equal or greater Id ratings, and compatible gate drive characteristics are suitable for direct substitution. The TO-220-3 package ensures mechanical and thermal interface compatibility. Gate charge and input capacitance variations are acceptable provided they do not exceed circuit design constraints.

The two identified substitute parts, STP4NK60Z and STP4NK80Z, both exceed the minimum voltage and current requirements of the FQP4N20 while maintaining compatible package and drive specifications.

Parameter Comparison

Parameter	FQP4N20 (Main)	STP4NK60Z	STP4NK80Z	Unit
Manufacturer	onsemi	STMicroelectronics	STMicroelectronics
Drain to Source Voltage (Vdss)	200	600	800	V
Continuous Drain Current (Id) @ 25°C	3.6	4	3	A
Rds On (Max) @ Id, Vgs	1.4 @ 1.8A, 10V	2 @ 2A, 10V	3.5 @ 1.5A, 10V	Ohm
Gate Threshold Voltage Vgs(th) (Max) @ Id	5 @ 250µA	4.5 @ 50µA	4.5 @ 50µA	V
Gate Charge (Qg) (Max) @ Vgs	6.5 @ 10V	26 @ 10V	22.5 @ 10V	nC
Input Capacitance (Ciss) (Max) @ Vds	220 @ 25V	510 @ 25V	575 @ 25V	pF
Power Dissipation (Max)	45	70	80	W
Operating Temperature Range	-55 to 150	-40 to 150	-55 to 150	°C
Package Type	TO-220-3	TO-220	TO-220
FET Type	N-Channel	N-Channel	N-Channel
Technology	MOSFET (Metal Oxide)	MOSFET (Metal Oxide)	MOSFET (Metal Oxide)
Product Status	Obsolete	Active	Active

Engineering Selection Recommendations

STP4NK60Z Selection: The STP4NK60Z is an active product from STMicroelectronics with 600V Vdss rating and 4A continuous drain current, exceeding the FQP4N20 specifications. This part is RoHS3 compliant and carries REACH Unaffected status, meeting modern regulatory requirements. The higher voltage rating provides design margin for transient overvoltage conditions. Gate charge is elevated at 26 nC compared to the FQP4N20's 6.5 nC, which may require gate driver circuit adjustment. Operating temperature range extends to -40°C minimum, which is acceptable for most applications requiring -55°C operation only in exceptional cases.

STP4NK80Z Selection: The STP4NK80Z is an active product from STMicroelectronics with 800V Vdss rating and 3A continuous drain current. This part maintains the full -55°C to 150°C operating temperature range of the FQP4N20. RoHS3 compliance and REACH Unaffected status are confirmed. The 800V rating provides maximum design margin for high-voltage transient protection. Rds On is higher at 3.5 Ohm, resulting in increased power dissipation in high-current applications. Gate charge of 22.5 nC and input capacitance of 575 pF require gate driver evaluation.

Recommendation Basis: Both substitute parts are active products with confirmed regulatory compliance. Selection between STP4NK60Z and STP4NK80Z depends on application voltage stress requirements and gate driver capability. The STP4NK80Z is preferred for applications requiring the full -55°C minimum operating temperature specification.

Frequently Asked Questions (FAQ)

Q: Can the STP4NK60Z directly replace the FQP4N20 in all applications?

A: The STP4NK60Z meets the minimum electrical requirements for substitution with higher Vdss (600V vs. 200V) and Id (4A vs. 3.6A) ratings. However, the operating temperature minimum is -40°C rather than -55°C. Applications requiring operation below -40°C require the STP4NK80Z. Gate charge is significantly higher (26 nC vs. 6.5 nC), necessitating gate driver circuit evaluation to ensure adequate switching speed and efficiency.

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

A: Gate charge directly affects gate driver power consumption and switching speed. The STP4NK60Z and STP4NK80Z have gate charges of 26 nC and 22.5 nC respectively, compared to 6.5 nC for the FQP4N20. Gate drivers must supply sufficient current to charge the gate within the required switching time. Existing gate driver circuits may require redesign or component substitution to accommodate the higher charge requirement.

Q: Are the substitute parts mechanically compatible with the FQP4N20?

A: Both STP4NK60Z and STP4NK80Z use TO-220 package configurations, which are mechanically and thermally compatible with the FQP4N20's TO-220-3 package. Pin assignments and mounting interfaces are identical, allowing direct PCB mounting without modification.

Q: What regulatory compliance differences exist between the main part and substitutes?

A: The FQP4N20 is obsolete with no RoHS status specified. Both STP4NK60Z and STP4NK80Z are active products with RoHS3 compliance and REACH Unaffected status, meeting current regulatory requirements for new designs and procurement.

Q: How do the Rds On specifications compare, and what is the practical impact?

A: The FQP4N20 has Rds On of 1.4 Ohm at 1.8A and 10V. The STP4NK60Z has 2 Ohm at 2A and 10V, and the STP4NK80Z has 3.5 Ohm at 1.5A and 10V. Higher Rds On increases conduction losses and heat dissipation. Applications with high continuous current or tight thermal budgets require power dissipation recalculation using the substitute part's Rds On specification.

Q: Can the STP4NK80Z be used in applications where the STP4NK60Z is specified?

A: Yes, the STP4NK80Z can substitute for the STP4NK60Z in most applications. The STP4NK80Z has higher Vdss (800V vs. 600V) and maintains the full -55°C to 150°C operating temperature range. However, Rds On is higher (3.5 Ohm vs. 2 Ohm), resulting in increased power dissipation. Gate charge is lower (22.5 nC vs. 26 nC), which may improve switching performance.

Q: What inventory status should influence substitution decisions?

A: The FQP4N20 has 15,116 pieces in stock as new original inventory. The STP4NK60Z has 45,200 pieces and the STP4NK80Z has 6,318 pieces available. For long-term supply chain security, the STP4NK60Z offers the highest inventory availability. The STP4NK80Z inventory is more limited but remains adequate for most procurement requirements.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message