FQT4N25 is a 250V N-channel MOSFET produced by Fairchild. It features low on-state resistance, low gate charge, low reverse capacitance, and is suitable for high-efficiency switching DC/DC converters and switch mode power supplies.
The FQT4N25 is a 250 V N‑Channel enhancement‑mode power MOSFET built with Fairchild’s planar stripe DMOS technology. It offers low gate charge, low output capacitance, and fast switching suitable for high‑efficiency DC‑DC converters and switch‑mode power supplies.
The document lists absolute maximum ratings, detailed electrical characteristics, typical performance curves, and mechanical dimensions for the SOT‑223 package, along with trademark and product status information.
| Drain‑Source Voltage (VDS) | 250 V |
|---|---|
| Continuous Drain Current (ID) @ 25 °C | 0.83 A |
| Pulsed Drain Current (ID) (max) | 3.3 A |
| Gate‑Source Voltage (VGS) | +30 V |
| Total Gate Charge (Qg) | typical 4.3 nC |
| Input Capacitance (Ciss) | 155‑200 pF |
| Output Capacitance (Coss) | 35‑45 pF |
| Reverse Transfer Capacitance (Crss) | 48‑65 pF |
| Power Dissipation (PD) @ 25 °C | 25 W |
| Junction‑to‑Ambient Thermal Resistance (RθJA) | 50 °C/W |
| On‑Resistance (RDS(on)) | typical 1.75‑1.88 mΩ |
| Package | SOT‑223 |
The device is rated for a maximum drain‑source voltage of 250 V.
It can conduct up to 0.83 A continuously at a junction temperature of 25 °C.
The typical total gate charge is about 4.3 nC.
The MOSFET is offered in an SOT‑223 surface‑mount package.