FQT4N20L is a N-Channel enhancement mode power field effect transistor produced by Fairchild Semiconductor Corporation. This transistor uses Fairchild's proprietary planar stripe DMOS technology, which is specially tailored to minimize on-state resistance, provide superior switching performance, and withstand high energy pulses in the avalanche and commutation mode. These devices are well suited for high efficiency switching DC/DC converters, switch mode power supply, DC-AC converters for uninterrupted power supply, motor control.
The FQT4N20L MOSFET is a N‑channel enhancement mode power transistor built with Fairchild’s planar stripe DMOS technology. It is designed for high‑efficiency switching in DC/DC converters, SMPS, UPS inverters, and motor‑control applications.
Key specifications include a 200 V drain‑source rating, 0.85 A continuous drain current at 25 °C, low gate charge (~4 nC), and a typical on‑resistance of 1.352 Ω at VGS = 10 V. The device features fast switching, 100 % avalanche testing, and a thermal resistance of 57 °C/W for SOT‑223 packaging.
| Drain‑Source Voltage (VDS) | 200 V |
|---|---|
| Continuous Drain Current (ID) @ 25 °C | 0.85 A |
| Typical Gate Charge (Qg) | 4.0 nC |
| On‑Resistance (RDS(on)) | 1.352 Ω @ VGS=10 V |
| Thermal Resistance (RθJA) | 57 °C/W |
The device is rated for a maximum drain‑source voltage of 200 V.
The typical gate charge is about 4 nC.
It can conduct up to 0.85 A continuously at 25 °C.
The junction‑to‑ambient thermal resistance is 57 °C/W.