FCH023N65S3 MOSFET — Specifications & Equivalents

About the FCH023N65S3

The FCH023N65S3 is an N-channel MOSFET with a drain–source voltage (V_DS) rating of 650 V, a continuous drain current (I_D) of 75 A and an on-resistance (R_DS(on)) of 0.023 Ω. It can dissipate up to 595 W and is rated to a junction temperature of 150 °C. It is supplied in the TO247 package.

At a glance

• Type: N-channel MOSFET
• Max drain–source voltage (V_DS): 650 V
• Max continuous drain current (I_D): 75 A
• On-resistance (R_DS(on)): 0.023 Ω
• Power dissipation (P_D): 595 W
• Max junction temperature (T_J): 150 °C
• Package: TO247

Typical applications

With its 650 V drain–source rating the FCH023N65S3 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 75 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 0.023 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 55 ns and an output capacitance (C_oss) of 195 pF, which together with the gate drive determines switching loss and the practical upper frequency limit.

Choosing a replacement for the FCH023N65S3

A drop-in substitute for the FCH023N65S3 must be the same N-channel type and offer a drain–source rating of at least 650 V, a continuous drain current rating of at least 75 A and an on-resistance no higher than 0.023 Ω if efficiency and heat matter.

Mechanically, check the replacement against the TO247 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 FCH023N65S3?

The FCH023N65S3 is an N-channel MOSFET (metal-oxide-semiconductor field-effect transistor). It is rated for 650 V drain-source and 75 A continuous drain current.

What is the maximum voltage of the FCH023N65S3?

The FCH023N65S3 has a maximum drain-source voltage (Vds) of 650 V. Treat this as an absolute maximum and design with margin, especially when switching inductive loads.

How much current can the FCH023N65S3 handle?

It is rated for 75 A of continuous drain current, with power dissipation limited to 595 W. Real-world capability depends on your heatsinking and ambient temperature.

What is the on-resistance of the FCH023N65S3?

On-resistance (Rds(on)) is 0.023 Ω. Multiply by the square of your load current to estimate conduction loss.

What package does the FCH023N65S3 come in?

It is listed in TO247. Verify the pinout of the specific variant, as one outline can carry different pin assignments.

What can I use to replace the FCH023N65S3?

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.