FQP3N80 Equivalent & Substitute Parts

Part Overview

The FQP3N80 is an N-Channel 800V 3A MOSFET manufactured by onsemi in the QFET® series, housed in a TO-220-3 through-hole package. This device is classified as obsolete, making identification of equivalent and substitute parts necessary for ongoing design support and production continuity. The FQP3N80 is suitable for high-voltage switching applications requiring moderate current handling at 800V drain-to-source voltage rating.

Key Parameters

Parameter	Value	Unit
Drain to Source Voltage (Vdss)	800	V
Continuous Drain Current (Id) @ 25°C	3	A
Rds On (Max) @ Id, Vgs	5	Ohm @ 1.5A, 10V
Gate Charge (Qg) (Max) @ Vgs	19	nC @ 10V
Power Dissipation (Max)	107	W
Operating Temperature Range	-55 to 150	°C
Package Type	TO-220-3	Through Hole
Vgs(th) (Max) @ Id	5	V @ 250µA
Input Capacitance (Ciss) (Max) @ Vds	690	pF @ 25V

Substitute Part Grouping Explanation

Substitution of the FQP3N80 is determined by the following critical electrical and mechanical parameters:

Primary Substitution Criteria:

Drain to Source Voltage (Vdss): Must equal or exceed 800V
Continuous Drain Current (Id): Must equal or exceed 3A at 25°C
Package Type: Must be TO-220-3 through-hole configuration
Operating Temperature Range: Must span -55°C to 150°C
Gate Drive Voltage: Must support 10V drive voltage

Secondary Compatibility Factors:

Rds On characteristics at specified gate voltage and current
Gate Charge (Qg) for switching speed considerations
Power Dissipation capability
Vgs(th) threshold voltage compatibility

Substitute parts are grouped into two categories: direct replacements with identical or superior electrical specifications, and functional alternatives with higher voltage or current ratings that maintain backward compatibility within the application's thermal and electrical constraints.

Parameter Comparison

Parameter	FQP3N80	FQP6N80C	STP2N80K5	STP3NK80Z	STP3NK90Z	STP4NK80Z	STP5NK80Z
Manufacturer	onsemi	onsemi	STMicroelectronics	STMicroelectronics	STMicroelectronics	STMicroelectronics	STMicroelectronics
Vdss (V)	800	800	800	800	900	800	800
Id @ 25°C (A)	3	5.5	2	2.5	3	3	4.3
Rds On (Max) @ 10V (Ohm)	5 @ 1.5A	2.5 @ 2.75A	4.5 @ 1A	4.5 @ 1.25A	4.8 @ 1.5A	3.5 @ 1.5A	2.4 @ 2.15A
Qg (Max) @ 10V (nC)	19	30	3	19	22.7	22.5	45.5
Power Dissipation (Max) (W)	107	158	45	70	90	80	110
Ciss (Max) @ 25V (pF)	690	1310	95	485	590	575	910
Vgs(th) (Max) (V)	5 @ 250µA	5 @ 250µA	5 @ 100µA	4.5 @ 50µA	4.5 @ 50µA	4.5 @ 50µA	4.5 @ 100µA
Operating Temperature (°C)	-55 to 150	-55 to 150	-55 to 150	-55 to 150	-55 to 150	-55 to 150	-55 to 150
Package	TO-220-3	TO-220-3	TO-220-3	TO-220-3	TO-220-3	TO-220-3	TO-220-3
Product Status	Obsolete	Active	Active	Active	Active	Active	Active
RoHS Status	Not Specified	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant

Engineering Selection Recommendations

Direct Replacement (Identical Specifications):

STP4NK80Z is the primary direct replacement for FQP3N80. Both devices share identical Vdss (800V) and Id (3A) ratings. STP4NK80Z offers improved Rds On performance (3.5 Ohm vs. 5 Ohm) and lower gate charge (22.5 nC vs. 19 nC), resulting in reduced switching losses. STP4NK80Z is ROHS3 compliant and carries active product status, ensuring long-term availability and supply chain continuity.

Higher Current Capability Substitutes:

FQP6N80C and STP5NK80Z provide increased current handling (5.5A and 4.3A respectively) while maintaining 800V Vdss rating. These devices are suitable for applications where thermal margin or current headroom is required. FQP6N80C remains within the onsemi QFET® family. STP5NK80Z offers the lowest Rds On (2.4 Ohm) among available substitutes, minimizing conduction losses in high-current scenarios.

Voltage-Rated Alternative:

STP3NK90Z provides 900V Vdss rating with 3A continuous current, matching the FQP3N80 current specification. This device is applicable in designs requiring enhanced voltage margin or operating in higher-voltage environments. Gate charge and Rds On characteristics remain comparable to the original device.

Lower Current Alternatives:

STP2N80K5 and STP3NK80Z provide reduced current ratings (2A and 2.5A respectively) with corresponding lower power dissipation. These devices are suitable for applications where the original 3A specification exceeds actual requirements, offering cost optimization and reduced thermal management demands.

All substitute parts maintain TO-220-3 through-hole packaging, -55°C to 150°C operating temperature range, and ±30V maximum gate voltage compatibility. All active-status substitutes are ROHS3 compliant, supporting modern environmental and regulatory requirements.

Frequently Asked Questions (FAQ)

Q: Can FQP6N80C directly replace FQP3N80 in all applications?

A: FQP6N80C is a direct functional replacement with superior electrical characteristics. The 5.5A continuous current rating exceeds the FQP3N80 specification of 3A, and the improved Rds On (2.5 Ohm vs. 5 Ohm) reduces conduction losses. Both devices share identical 800V Vdss rating and TO-220-3 packaging. Thermal design must accommodate the higher power dissipation capability (158W vs. 107W). No circuit modifications are required.

Q: What is the difference between STP4NK80Z and STP5NK80Z?

A: Both devices maintain 800V Vdss rating and TO-220-3 packaging. STP4NK80Z provides 3A continuous current with 3.5 Ohm Rds On and 80W power dissipation. STP5NK80Z provides 4.3A continuous current with 2.4 Ohm Rds On and 110W power dissipation. STP5NK80Z is selected for applications requiring higher current capacity or lower conduction losses. STP4NK80Z is selected for applications matching the original 3A specification with improved efficiency.

Q: Why is STP3NK90Z listed as a substitute if it has 900V rating instead of 800V?

A: STP3NK90Z maintains identical 3A continuous current and TO-220-3 packaging as FQP3N80. The 900V Vdss rating provides additional voltage margin without reducing current capability. This device is suitable for applications where the circuit operates below 800V or where enhanced voltage headroom is beneficial. The higher voltage rating does not create incompatibility in 800V-rated designs.

Q: Are all substitute parts ROHS3 compliant?

A: All active-status substitute parts (FQP6N80C, STP2N80K5, STP3NK80Z, STP3NK90Z, STP4NK80Z, STP5NK80Z) are ROHS3 compliant. The FQP3N80 original part does not specify RoHS status. ROHS3 compliance ensures compatibility with modern manufacturing and environmental regulations.

Q: What is the significance of gate charge (Qg) differences among substitutes?

A: Gate charge affects switching speed and driver circuit requirements. FQP3N80 specifies 19 nC at 10V. STP2N80K5 has significantly lower gate charge (3 nC), enabling faster switching with lower driver power consumption. STP5NK80Z has higher gate charge (45.5 nC), requiring more driver current but providing improved noise immunity. Selection depends on the gate driver circuit capability and switching frequency requirements.

Q: Can STP2N80K5 be used if the application requires only 2A instead of 3A?

A: STP2N80K5 is suitable for applications with 2A or lower continuous current requirements. The device provides 800V Vdss rating, TO-220-3 packaging, and -55°C to 150°C operating range matching FQP3N80. The 2A rating reduces power dissipation (45W vs. 107W), simplifying thermal management. No circuit modifications are required for current-limited applications.

Q: What packaging considerations apply to these substitutes?

A: All substitute parts use TO-220-3 through-hole packaging, identical to FQP3N80. Pin configuration and mechanical dimensions are compatible. PCB layout and heatsink mounting remain unchanged. No mechanical redesign is required for substitution.

Q: How do Rds On differences affect circuit performance?

A: Rds On determines conduction losses and heat generation. FQP3N80 specifies 5 Ohm at 1.5A and 10V. Lower Rds On values (STP4NK80Z at 3.5 Ohm, STP5NK80Z at 2.4 Ohm) reduce conduction losses and heat dissipation. Higher Rds On values (STP2N80K5 at 4.5 Ohm) increase losses. Selection depends on thermal budget and efficiency requirements. Improved Rds On in substitutes generally reduces system power consumption.

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