Vishay Siliconix IRFI820G

Overview

IRFI820G from Vishay Siliconix is a 500 V, 2.1 A N-channel power MOSFET in TO-220 FULLPAK package with isolated tab, 3.0 Ω R_DS(on) at V_GS = 10 V, 24 nC total gate charge, and 2.5 kV_RMS isolation rating - designed for high-voltage flyback and offline SMPS primary-side switching.

For engineers reviewing the IRFI820G datasheet, IRFI820G pinout, IRFI820G application, or IRFI820G equivalent, this device is selected for isolated high-voltage DC-DC converters, AC-DC adapters requiring creepage >4.8 mm, and ruggedized industrial power supplies where avalanche energy (110 mJ) and dV/dt immunity (3.5 V/ns) are critical.

Technical Context

The IRFI820G employs a third-generation planar vertical DMOS structure optimized for fast switching and avalanche ruggedness. Its TO-220 FULLPAK package integrates a molded isolating barrier between drain and heatsink, eliminating external insulation hardware while maintaining 4.1 °C/W junction-to-case thermal resistance.

It features a body diode with 260–520 ns reverse recovery time and 0.70–1.4 μC Q_rr, supporting unclamped inductive switching up to 8.4 A pulsed drain current. Gate drive is compatible with standard 10 V logic-level controllers, with V_GS(th) spanning 2.0–4.0 V and ±100 nA gate leakage.

Key Specifications

Pinout & Package

IRFI820G uses the TO-220 FULLPAK package: isolated plastic body with metal tab (drain-connected), 3-pin through-hole configuration, 15.87 mm length, 10.10 mm width, and 4.70 mm height. The tab provides electrical isolation up to 2.5 kV_RMS and thermal path to heatsink.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STP5NK50ZFP and FQP5N50CTU, the IRFI820G uniquely delivers integrated 2.5 kV_RMS isolation and 4.8 mm creepage in a drop-in TO-220 footprint - eliminating insulator hardware, reducing thermal resistance by ~25%, and enabling faster certification for medical and consumer AC-DC power supplies.

Availability

IRFI820G is available at Aetrix Electronics and suitable for AC-DC adapters, industrial SMPS, and isolated LED drivers requiring stable component supply, long-term lifecycle support, and traceable sourcing for safety-critical designs.

Supply support for IRFI820G 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 high-reliability MOSFETs, diodes, and optoelectronics for power, sensing, and signal conditioning applications.

The IRFI820G belongs to Vishay's high-voltage isolated MOSFET product line, engineered specifically for safety-certified offline power conversion where reinforced insulation, creepage, and avalanche ruggedness are mandatory design constraints.

FAQ

What is the maximum continuous drain current for IRFI820G at 100 °C case temperature?

The IRFI820G supports 1.3 A continuous drain current at T_C = 100 °C, as specified in the Absolute Maximum Ratings table. This derating reflects thermal limits of the TO-220 FULLPAK package and ensures safe operation within its 150 °C maximum junction temperature. Designers must verify heatsink sizing using the 4.1 °C/W R_thJC value to maintain T_J ≤ 150 °C under full load. The IRFI820G datasheet confirms this rating applies under steady-state conduction with proper heatsinking.

Does IRFI820G have a built-in gate protection diode?

No, the IRFI820G does not integrate a gate protection Zener diode. Its gate-source voltage rating is ±20 V, and gate leakage is specified at ±100 nA at ±20 V. External gate protection - such as a 15 V Zener clamp or RC snubber - is recommended when driving with controllers prone to overshoot or in noisy industrial environments. The IRFI820G datasheet explicitly lists only static and dynamic parameters without gate protection circuitry.

Can IRFI820G be used in synchronous rectification applications?

No, the IRFI820G is not suitable for synchronous rectification. It is an N-channel high-voltage primary-side switch with 3.0 Ω R_DS(on) and optimized for 500 V blocking, not low-V_DS conduction. Synchronous rectifiers require low-threshold, low-R_DS(on) MOSFETs (typically ≤100 mΩ) with fast body diodes - characteristics not present in the IRFI820G. Its body diode t_rr (260–520 ns) and Q_rr (0.70–1.4 μC) are intended for unclamped inductive switching, not high-frequency rectification.

What is the drain-to-sink capacitance of IRFI820G and why does it matter?

The IRFI820G has a drain-to-sink capacitance of 12 pF, measured at 1.0 MHz. This parameter directly impacts EMI filter design and common-mode noise coupling in isolated power supplies. A low C_DS minimizes capacitive coupling from high-dv/dt drain nodes to grounded heatsinks, reducing conducted emissions and easing compliance with EN 55032 Class B. The IRFI820G's 12 pF value is confirmed in the "Dynamic" section of its official datasheet (Document Number: 91158).

Is IRFI820G RoHS-compliant and lead-free?

Yes, the IRFI820G is RoHS-compliant and lead-free, as indicated by its ordering variant IRFI820GPbF (Pb-free). Vishay certifies compliance per EU Directive 2011/65/EU and JEDEC J-STD-609, with material declarations available in Document Number 91158. The "PbF" suffix confirms termination finish meets RoHS exemption 7a for high-melting-point solder alloys, and the device is suitable for lead-free reflow processes up to 260 °C peak temperature.