FC40SA50FKP MOSFET — Specifications & Equivalents
About the FC40SA50FKP
The FC40SA50FKP is an N-channel MOSFET with a drain–source voltage (VDS) rating of 500 V, a continuous drain current (ID) of 40 A and an on-resistance (RDS(on)) of 0.1 Ω. It can dissipate up to 430 W and is rated to a junction temperature of 150 °C. It is supplied in the SOT-227 package.
At a glance
- Type: N-channel MOSFET
- Max drain–source voltage (VDS): 500 V
- Max continuous drain current (ID): 40 A
- On-resistance (RDS(on)): 0.1 Ω
- Power dissipation (PD): 430 W
- Max junction temperature (TJ): 150 °C
- Package: SOT-227
Typical applications
With its 500 V drain–source rating the FC40SA50FKP sits in the high-voltage (offline) class of switching MOSFETs, typically found in primary-side switching in offline SMPS (flyback, forward and quasi-resonant), active PFC boost stages, half-bridge and full-bridge inverters, induction heating and electronic ballasts and BLDC and AC motor drives. The rating leaves usable margin above the ~325 V DC bus obtained by rectifying 230 VAC mains, which is why this class dominates offline power supplies.
Gate drive and switching notes
Keep gate–source voltage within the ±30 V maximum; exceeding it punctures the gate oxide and destroys the device permanently.
Switching behaviour is characterised by a rise time of 140 ns and an output capacitance (Coss) of 960 pF, which together with the gate drive determines switching loss and the practical upper frequency limit.
Choosing a replacement for the FC40SA50FKP
A drop-in substitute for the FC40SA50FKP must be the same N-channel type and offer a drain–source rating of at least 500 V, a continuous drain current rating of at least 40 A and an on-resistance no higher than 0.1 Ω if efficiency and heat matter.
Mechanically, check the replacement against the SOT-227 footprint and confirm the pin order — parts sharing a package outline do not always share a pinout.
Where the application switches inductive loads or runs near the voltage limit, keep extra headroom rather than choosing a part that only just meets the original numbers.
Frequently asked questions
What is the FC40SA50FKP?
The FC40SA50FKP is an N-channel MOSFET (metal-oxide-semiconductor field-effect transistor). It is rated for 500 V drain-source and 40 A continuous drain current.
What is the maximum voltage of the FC40SA50FKP?
The FC40SA50FKP has a maximum drain-source voltage (Vds) of 500 V. Treat this as an absolute maximum and design with margin, especially when switching inductive loads.
How much current can the FC40SA50FKP handle?
It is rated for 40 A of continuous drain current, with power dissipation limited to 430 W. Real-world capability depends on your heatsinking and ambient temperature.
What is the on-resistance of the FC40SA50FKP?
On-resistance (Rds(on)) is 0.1 Ω. Multiply by the square of your load current to estimate conduction loss.
What package does the FC40SA50FKP come in?
It is listed in SOT-227. Verify the pinout of the specific variant, as one outline can carry different pin assignments.
What can I use to replace the FC40SA50FKP?
No verified equivalents are listed yet. Choose a part of the same polarity that meets or exceeds every rating above and shares a compatible package and pinout.
Key Specifications
| Type | MOSFET |
|---|---|
| Channel Type | N -Channel |
| Drain-Source Voltage (Vds) | 500 V |
| Gate-Source Voltage (Vgs) | 30 V |
| Drain Current (Id) | 40 A |
| Drain-Source On-Resistance (Rds) | 0.1 |
| Rise Time (tr) | 140 nS |
| Output Capacitance (Coss) | 960 pF |
| Junction Temperature (Tj) | 150 °C |
| Package | SOT-227 |
| Power Dissipation (Pd) | 430 W |
Equivalent & Replacement Parts
No verified equivalents are listed for FC40SA50FKP yet.