Vishay Siliconix IRFIBF20G

Overview

IRFIBF20G from Vishay Siliconix is a high-voltage N-channel power MOSFET in TO-220 FULLPAK package, rated for 900 V drain-source voltage, 8.0 Ω on-resistance at V_GS = 10 V, and 1.2 A continuous drain current at T_C = 25 °C. It delivers isolated mounting capability (2.5 kV_RMS, 60 s), low thermal resistance (R_thJC = 4.1 °C/W), and robust avalanche performance (E_AS = 150 mJ), enabling use in offline SMPS flyback and auxiliary power supplies.

For engineers reviewing the IRFIBF20G datasheet, IRFIBF20G pinout, IRFIBF20G application, or IRFIBF20G equivalent, key selection considerations include its high-voltage isolation rating, TO-220 FULLPAK thermal and mounting advantages over standard TO-220, body diode recovery characteristics (t_rr = 350–530 ns), and gate charge profile (Q_g = 38 nC) for hard-switched topologies.

Technical Context

The IRFIBF20G employs a third-generation silicon process optimized for high-voltage ruggedness and fast switching trade-offs. Its isolated TO-220 FULLPAK construction integrates high-dielectric-strength molding compound-equivalent to a 100 µm mica barrier-enabling direct heatsink mounting without insulating hardware. The device features a dynamic dV/dt rating of 1.5 V/ns and intrinsic body diode with Q_rr = 0.85–1.3 µC.

Thermal design leverages low junction-to-case resistance (4.1 °C/W) and supports linear derating (0.24 W/°C above 25 °C). Electrical behavior includes V_GS(th) = 2.0–4.0 V, R_DS(on) temperature coefficient of +1.1 V/°C, and C_iss/C_oss/C_rss values of 490/55/18 pF respectively at V_DS = 25 V, supporting predictable gate drive sizing.

Key Specifications

Pinout & Package

IRFIBF20G uses the TO-220 FULLPAK package: an isolated variant of TO-220 with integrated high-isolation molding compound, single-screw mounting, and tab connected to drain. Dimensions conform to Vishay document 91359 (Option 1 or 2), with exposed copper tab (drain) on underside and three leads (G, D, S) on front edge.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage N-channel MOSFET applications.

Compared with STP9NK90ZFP and IXTP50N10P, the IRFIBF20G uniquely combines certified 2.5 kV_RMS isolation, TO-220 FULLPAK mounting simplicity, and optimized 1.2 A/900 V operation-making it the only choice for compact, insulator-free auxiliary supplies requiring regulatory-compliant creepage/clearance.

Availability

IRFIBF20G is available at Aetrix Electronics and suitable for AC-DC auxiliary power supplies, flyback converter primary switches, and industrial control input stages requiring stable component supply across extended production lifecycles.

Supply support for IRFIBF20G includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Vishay Siliconix is a global leader in discrete semiconductors, specializing in power MOSFETs, diodes, and optoelectronics with emphasis on ruggedness, reliability, and high-voltage performance.

The IRFIBF20G belongs to Vishay's high-voltage isolated MOSFET product line, engineered specifically for safety-critical, space-constrained auxiliary power and industrial control applications where isolation integrity and thermal efficiency are non-negotiable.

FAQ

What is the maximum continuous drain current rating for IRFIBF20G at 100 °C case temperature?

The IRFIBF20G has a continuous drain current rating of 0.79 A at T_C = 100 °C, per the Absolute Maximum Ratings table. This derating reflects thermal limitations of the TO-220 FULLPAK package and must be applied in thermally constrained layouts. Designers should verify junction temperature using R_thJC = 4.1 °C/W and actual power dissipation to ensure safe operation below 150 °C.

Does IRFIBF20G require an external insulator when mounted to a heatsink?

No, the IRFIBF20G does not require an external insulator. Its TO-220 FULLPAK package incorporates high-isolation molding compound rated for 2.5 kV_RMS (60 s), eliminating the need for mica washers or silicone pads. The drain-connected tab can be directly bolted to the heatsink using a single M3 screw (torque = 0.6 Nm), simplifying mechanical assembly and improving thermal transfer.

What is the typical body diode reverse recovery time (t_rr) for IRFIBF20G, and how does it affect flyback operation?

The IRFIBF20G exhibits a typical body diode reverse recovery time of 350–530 ns at T_J = 25 °C, I_F = 1.7 A, and dI/dt = 100 A/μs. In flyback converters operating in discontinuous conduction mode, this t_rr contributes to measurable recovery loss and EMI during primary switch turn-on. Designers should account for it in snubber sizing and layout to minimize voltage overshoot and ensure stable regulation.

Can IRFIBF20G be used in avalanche-mode operation, and what is its rated single-pulse energy?

Yes, the IRFIBF20G is rated for single-pulse avalanche operation with E_AS = 150 mJ under specified test conditions (V_DD = 50 V, L = 196 mH, R_G = 25 Ω, I_AS = 1.2 A). This rating validates its ability to absorb inductive energy during unclamped switching events-such as transformer reset in flyback topologies-without failure, provided peak junction temperature remains within limits.

What gate drive voltage is required to fully enhance IRFIBF20G, and what is its threshold range?

The IRFIBF20G requires V_GS = 10 V for full enhancement, delivering R_DS(on) ≤ 8.0 Ω. Its gate-source threshold voltage (V_GS(th)) ranges from 2.0 V to 4.0 V at I_D = 250 µA, meaning logic-level drivers (e.g., 5 V) will partially turn it on but cannot achieve specified on-resistance. A dedicated 10 V gate driver is recommended for optimal conduction efficiency and switching consistency.