Vishay Siliconix IRFBF20S

Overview

IRFBF20S from Vishay Siliconix is a 900 V, 8.0 Ω (at V_GS = 10 V), N-channel surface-mount power MOSFET in D2PAK (TO-263) package, rated for 1.7 A continuous drain current at T_C = 25 °C and fully avalanche-rated for robustness in high-voltage switching applications such as offline SMPS and AC-DC adapters.

For engineers reviewing the IRFBF20S datasheet, IRFBF20S pinout, IRFBF20S application, or IRFBF20S equivalent, key selection criteria include its 900 V V_DS, 38 nC total gate charge, 150 °C maximum junction temperature, dynamic dV/dt rating of 1.5 V/ns, and D2PAK thermal performance with R_thJC = 2.3 °C/W.

Technical Context

This device belongs to Vishay's third-generation high-voltage power MOSFET family optimized for fast switching and ruggedized operation. Its design integrates low on-resistance with high avalanche energy capability (E_AS = 180 mJ), enabling reliable unclamped inductive switching in flyback and forward converters.

The IRFBF20S uses planar vertical DMOS technology with a fully isolated gate structure. It features a body diode with t_rr = 350–530 ns and Q_rr = 0.85–1.3 μC, supporting moderate-frequency hard-switched topologies where reverse recovery behavior impacts efficiency and EMI.

Key Specifications

Pinout & Package

D2PAK (TO-263) surface-mount package with exposed drain pad for thermal and electrical connection; 3-pin configuration (G, D, S) with drain tab electrically and thermally connected to pins 2 and 3 (D and S tied internally in package layout).

Key Features

Applications

Equivalent & Alternatives

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

Compared with IRFBF20S, SiHFBF20S-GE3 offers identical electrical performance with enhanced environmental compliance, while IRFBC40A provides lower gate charge but insufficient voltage rating and incompatible packaging-making IRFBF20S the only viable D2PAK solution for 900 V surface-mount requirements.

Availability

IRFBF20S is available at Aetrix Electronics and suitable for offline AC-DC adapters, industrial flyback converters, and high-voltage LED driver power stages requiring stable component supply across production lifecycles.

Supply support for IRFBF20S 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 IRFBF20S belongs to Vishay's third-generation high-voltage power MOSFET product line, engineered specifically for demanding offline switching applications where avalanche robustness, thermal efficiency, and surface-mount scalability are critical.

FAQ

What is the maximum continuous drain current rating for IRFBF20S at 100 °C case temperature?

The IRFBF20S supports 1.1 A continuous drain current at T_C = 100 °C, as specified in the Absolute Maximum Ratings table. This derating reflects thermal limitations of the D2PAK package and must be applied when heatsinking is limited or ambient temperature exceeds 50 °C. Designers should verify junction temperature using R_thJC = 2.3 °C/W and actual power dissipation to ensure T_J ≤ 150 °C. The IRFBF20S datasheet provides derating curves in Figure 9.

Does IRFBF20S have a built-in body diode, and what are its key recovery characteristics?

Yes, the IRFBF20S integrates a monolithic body diode with typical reverse recovery time (t_rr) of 350–530 ns and reverse recovery charge (Q_rr) of 0.85–1.3 μC at T_J = 25 °C, I_F = 1.7 A, and dI/dt = 100 A/μs. These values impact EMI and switching loss in hard-commutated topologies. The body diode forward voltage is 1.5 V at I_S = 1.7 A, V_GS = 0 V. For synchronous rectification, an external Schottky diode is recommended due to the MOSFET's non-optimized diode structure.

Is IRFBF20S pin-compatible with other devices in the same D2PAK package family, such as SiHFBF20S?

Yes, IRFBF20S is mechanically and electrically pin-compatible with SiHFBF20S-GE3 and SiHFBF20STRL-GE3, sharing identical D2PAK (TO-263) pinout (G-D-S), thermal pad layout, and footprint dimensions. Both devices use the same silicon die and differ only in termination finish (Pb-based vs. Pb-free/halogen-free) and reel packaging specifications. No PCB changes are required when substituting between these variants.

What is the gate threshold voltage range for IRFBF20S, and how does it affect drive circuit design?

The IRFBF20S has a gate threshold voltage (V_GS(th)) range of 2.0 V to 4.0 V at I_D = 250 μA, meaning it begins conducting significantly above 2 V but achieves full enhancement near 10 V. Drive circuits must supply ≥10 V to ensure R_DS(on) remains at the specified 8.0 Ω. Logic-level drivers (e.g., 3.3 V or 5 V) will not fully enhance the device and result in excessive conduction loss. A dedicated 12 V gate driver with ≥100 mA peak current is recommended for reliable switching.

Can IRFBF20S be used in avalanche mode repeatedly, and what are the limits?

The IRFBF20S is fully rated for repetitive avalanche operation with I_AR = 1.7 A and E_AR = 5.4 mJ per pulse, provided pulse width and duty cycle remain within limits defined by maximum junction temperature (T_J ≤ 150 °C). Repetitive avalanche is validated per test condition "a" in the datasheet (pulse width limited by T_J max, see Figure 11). Designers must calculate cumulative heating from avalanche pulses and ensure thermal design sustains average power within PD = 54 W at T_C = 25 °C.