UMW IRF7821TR

Overview

IRF7821TR from Infineon Technologies is a 30V, 13A N-channel HEXFET Power MOSFET in SO-8 package, optimized as the synchronous FET in high-frequency buck converters. It features 7.0 mΩ R_DS(on) at V_GS = 10 V, 9.3 nC total gate charge, and fully characterized avalanche capability (44 mJ E_AS). It is used in point-of-load DC/DC stages for networking and computing systems where low conduction loss and fast switching are critical.

For engineers reviewing the IRF7821TR datasheet, IRF7821TR pinout, IRF7821TR application, or IRF7821TR equivalent, key selection criteria include R_DS(on) at 4.5 V (9.1 mΩ max), Q_gd/Q_gs1 ratio for C_dv/dt immunity, body diode reverse recovery (Q_rr = 23–35 nC), and SO-8 thermal performance (R_θJA = 50 °C/W).

Technical Context

The IRF7821TR is designed specifically for the low-side synchronous rectifier position in non-isolated buck converters, where its low R_DS(on) minimizes conduction loss while its low Q_gd (2.9 nC) and Q_gd/Q_gs1 ratio reduce susceptibility to C_dv/dt turn-on during high dV/dt node transitions. Its fully rated avalanche energy (44 mJ) supports robust operation under unclamped inductive switching stress.

It integrates a co-packaged body diode with 1.0 V forward voltage (V_SD) and 28–42 ns reverse recovery time (t_rr), enabling efficient freewheeling without external Schottky diodes. Gate threshold voltage (V_GS(th)) is 1.0–2.6 V, ensuring reliable enhancement-mode turn-on with standard 3.3 V or 5 V gate drivers.

Key Specifications

Pinout & Package

IRF7821TR is housed in a standard SO-8 surface-mount package with exposed drain pad for enhanced thermal performance. Pin 1–3 and 5–7 are drain terminals (D), Pin 4 is gate (G), and Pins 6 and 8 are source (S). The top view layout confirms dual-source and quad-drain configuration for low-inductance, high-current routing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SiR872DP-T1-GE3 and IPB070N15N3G, the IRF7821TR offers the best balance of low gate charge (9.3 nC), proven C_dv/dt immunity, and SO-8 manufacturability for high-volume computing PoL designs operating up to 1 MHz.

Availability

IRF7821TR is available at Aetrix Electronics and suitable for server VRMs, network switch point-of-load converters, and GPU core power supplies requiring stable component supply and consistent SO-8 assembly compatibility.

Supply support for IRF7821TR 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

Infineon Technologies is a German semiconductor manufacturer specializing in power management, automotive, and industrial control ICs and discrete devices.

The IRF7821TR belongs to the HEXFET® Power MOSFET product line, engineered for high-efficiency, high-frequency DC/DC conversion in computing and communications infrastructure where low R_DS(on), fast switching, and avalanche ruggedness are essential.

FAQ

Is IRF7821TR suitable for 3.3 V gate drive?

Yes. With a gate threshold voltage (V_GS(th)) of 1.0–2.6 V and R_DS(on) = 9.1 mΩ max at V_GS = 4.5 V, the IRF7821TR delivers usable on-resistance under 3.3 V logic drive-though full 10 V drive is recommended for minimum R_DS(on) and optimal efficiency in high-current applications.

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

The datasheet specifies 11 A continuous drain current at T_A = 70 °C. At T_C = 100 °C, derating applies: using R_θJC ≈ 20 °C/W (from R_θJL = 20 °C/W), junction temperature reaches 150 °C at ~10 A. Therefore, 8–9 A is the practical maximum for sustained operation at 100 °C case temperature with adequate margin.

Does IRF7821TR require a gate resistor for stability?

A small gate resistor (typically 1–10 Ω) is recommended to dampen ringing caused by PCB trace inductance and MOSFET input capacitance. While not strictly required for basic turn-on/turn-off, it improves EMI performance and prevents unintended oscillation-especially critical in high-dV/dt synchronous buck nodes where C_dv/dt coupling is present.

Can IRF7821TR replace IRF7807 in existing designs?

Yes, with verification. Both are SO-8 N-channel MOSFETs with similar V_DS (30 V) and R_DS(on) (IRF7807: 11 mΩ @ 10 V vs. IRF7821TR: 7.0 mΩ). The IRF7821TR offers lower R_DS(on), lower Q_g, and improved avalanche rating-making it a functional upgrade. Layout and gate drive must be confirmed for increased switching speed and reduced Miller effect.