IRFP343 MOSFET — Specifications & Equivalents
Manufacturer: Commonly produced by International Rectifier (now Infineon)
About the IRFP343
The IRFP343 is a MOSFET with a drain–source voltage (VDS) rating of 350 V and a continuous drain current (ID) of 8.3 A. It can dissipate up to 125 W and is rated to a junction temperature of 150 °C. It is supplied in the TO3P package.
At a glance
- Type: MOSFET
- Max drain–source voltage (VDS): 350 V
- Max continuous drain current (ID): 8.3 A
- Power dissipation (PD): 125 W
- Max junction temperature (TJ): 150 °C
- Package: TO3P
- Manufacturer: Commonly produced by International Rectifier (now Infineon)
Typical applications
With its 350 V drain–source rating the IRFP343 sits in the medium-high-voltage class of switching MOSFETs, typically found in telecom and industrial DC rails, boost and flyback converters, LED and backlight drivers and power-factor-correction stages. Common where the bus sits well above 100 V but below rectified mains.
Gate drive and switching notes
Keep gate–source voltage within the ±20 V maximum; exceeding it punctures the gate oxide and destroys the device permanently.
Switching behaviour is characterised by an output capacitance (Coss) of 178 pF, which together with the gate drive determines switching loss and the practical upper frequency limit.
Choosing a replacement for the IRFP343
A drop-in substitute for the IRFP343 should match its polarity and offer a drain–source rating of at least 350 V and a continuous drain current rating of at least 8.3 A.
Mechanically, check the replacement against the TO3P 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 IRFP343?
The IRFP343 is a MOSFET (metal-oxide-semiconductor field-effect transistor). It is rated for 350 V drain-source and 8.3 A continuous drain current.
What is the maximum voltage of the IRFP343?
The IRFP343 has a maximum drain-source voltage (Vds) of 350 V. Treat this as an absolute maximum and design with margin, especially when switching inductive loads.
How much current can the IRFP343 handle?
It is rated for 8.3 A of continuous drain current, with power dissipation limited to 125 W. Real-world capability depends on your heatsinking and ambient temperature.
What package does the IRFP343 come in?
It is listed in TO3P. Verify the pinout of the specific variant, as one outline can carry different pin assignments.
What can I use to replace the IRFP343?
This page lists 17 candidate equivalents matched on electrical ratings and package. Any replacement should meet or exceed the original voltage, current and dissipation figures and use a compatible drive level.
Key Specifications
| Pd ⓘ - Maximum Power Dissipation | 125 W |
|---|---|
| |Vds|ⓘ - Maximum Drain-Source Voltage | 350 V |
| |Vgs|ⓘ - Maximum Gate-Source Voltage | 20 V |
| |Id| ⓘ - Maximum Drain Current | 8.3 A |
| Tj ⓘ - Maximum Junction Temperature | 150 °C |
| Cossⓘ - Output Capacitance | 178 pF |
| Package | TO3P |
| INCHANGE Semiconductor isc Product Specification isc N-Channel MOSFET Transistor IRFP343R FEATURES Drain Current ID= 8.7A@ TC=25 Drain Source Voltage- | VDSS= 350V(Min) Static Drain-Source On-Resistance : RDS(on) = 0.80(Max) Fast Switching DESCRIPTION Designed for use in switch mode power supplies and general purpose applications. ABSOLUTE MAXIMUM RA |