APT50M38JFLL MOSFET — Specifications & Equivalents

About the APT50M38JFLL

The APT50M38JFLL is an N-channel MOSFET with a drain–source voltage (V_DS) rating of 500 V, a continuous drain current (I_D) of 91 A and an on-resistance (R_DS(on)) of 0.038 Ω. It can dissipate up to 775 W and is rated to a junction temperature of 150 °C. It is supplied in the SOT227 package.

At a glance

• Type: N-channel MOSFET
• Max drain–source voltage (V_DS): 500 V
• Max continuous drain current (I_D): 91 A
• On-resistance (R_DS(on)): 0.038 Ω
• Power dissipation (P_D): 775 W
• Max junction temperature (T_J): 150 °C
• Package: SOT227
• Manufacturer: Commonly produced by Advanced Power Technology (now Microchip)

Typical applications

With its 500 V drain–source rating the APT50M38JFLL 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.

The 91 A current rating puts it in high-current territory, where conduction loss (I² × R_DS(on)) and thermal design usually matter more than switching loss. Budget for adequate copper area and a heatsink.

The low 0.038 Ω on-resistance keeps conduction loss down, which suits synchronous rectification and continuous high-current paths.

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 18 ns and an output capacitance (C_oss) of 2610 pF, which together with the gate drive determines switching loss and the practical upper frequency limit.

Choosing a replacement for the APT50M38JFLL

A drop-in substitute for the APT50M38JFLL 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 91 A and an on-resistance no higher than 0.038 Ω if efficiency and heat matter.

Mechanically, check the replacement against the SOT227 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 APT50M38JFLL?

The APT50M38JFLL is an N-channel MOSFET (metal-oxide-semiconductor field-effect transistor). It is rated for 500 V drain-source and 91 A continuous drain current.

What is the maximum voltage of the APT50M38JFLL?

The APT50M38JFLL 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 APT50M38JFLL handle?

It is rated for 91 A of continuous drain current, with power dissipation limited to 775 W. Real-world capability depends on your heatsinking and ambient temperature.

What is the on-resistance of the APT50M38JFLL?

On-resistance (Rds(on)) is 0.038 Ω. Multiply by the square of your load current to estimate conduction loss.

What package does the APT50M38JFLL come in?

It is listed in SOT227. Verify the pinout of the specific variant, as one outline can carry different pin assignments.

What can I use to replace the APT50M38JFLL?

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.