FDB3502 MOSFET — Specifications & Equivalents
Manufacturer: Commonly produced by Fairchild (now onsemi)
About the FDB3502
The FDB3502 is an N-channel MOSFET with a drain–source voltage (VDS) rating of 75 V, a continuous drain current (ID) of 14 A and an on-resistance (RDS(on)) of 0.047 Ω. It can dissipate up to 41 W and is rated to a junction temperature of 150 °C. It is available in TO263 and D2PAK packages, so confirm the pinout of the exact variant you order.
At a glance
- Type: N-channel MOSFET
- Max drain–source voltage (VDS): 75 V
- Max continuous drain current (ID): 14 A
- On-resistance (RDS(on)): 0.047 Ω
- Power dissipation (PD): 41 W
- Max junction temperature (TJ): 150 °C
- Package: TO263, D2PAK
- Manufacturer: Commonly produced by Fairchild (now onsemi)
Typical applications
With its 75 V drain–source rating the FDB3502 sits in the mid-range class of switching MOSFETs, typically found in 24 V and 48 V industrial and battery systems, motor drives and H-bridges and load and hot-swap switching.
The low 0.047 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 ±20 V maximum; exceeding it punctures the gate oxide and destroys the device permanently.
Choosing a replacement for the FDB3502
A drop-in substitute for the FDB3502 must be the same N-channel type and offer a drain–source rating of at least 75 V, a continuous drain current rating of at least 14 A and an on-resistance no higher than 0.047 Ω if efficiency and heat matter.
Mechanically, check the replacement against the TO263 and D2PAK 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 FDB3502?
The FDB3502 is an N-channel MOSFET (metal-oxide-semiconductor field-effect transistor). It is rated for 75 V drain-source and 14 A continuous drain current.
What is the maximum voltage of the FDB3502?
The FDB3502 has a maximum drain-source voltage (Vds) of 75 V. Treat this as an absolute maximum and design with margin, especially when switching inductive loads.
How much current can the FDB3502 handle?
It is rated for 14 A of continuous drain current, with power dissipation limited to 41 W. Real-world capability depends on your heatsinking and ambient temperature.
What is the on-resistance of the FDB3502?
On-resistance (Rds(on)) is 0.047 Ω. Multiply by the square of your load current to estimate conduction loss.
What package does the FDB3502 come in?
It is listed in TO263 and D2PAK. Verify the pinout of the specific variant, as one outline can carry different pin assignments.
What can I use to replace the FDB3502?
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) | 75 V |
| Gate-Source Voltage (Vgs) | 20 V |
| Drain Current (Id) | 14 A |
| Drain-Source On-Resistance (Rds) | 0.047 |
| Junction Temperature (Tj) | 150 °C |
| Package | TO263 D2PAK |
| Power Dissipation (Pd) | 41 W |
Equivalent & Replacement Parts
No verified equivalents are listed for FDB3502 yet.