Vishay Siliconix IRFZ44S

Overview

IRFZ44S from Vishay Siliconix is a surface-mount N-channel power MOSFET in D2PAK (TO-263) package, rated for 60 V drain-source voltage, 50 A continuous drain current at 25 °C, and 0.028 Ω R_DS(on) at V_GS = 10 V. It delivers fast switching, 175 °C operating junction temperature, and robust avalanche capability (100 mJ), making it suitable for high-current DC-DC converters and motor drive half-bridges.

For engineers reviewing the IRFZ44S datasheet, IRFZ44S pinout, IRFZ44S application, or IRFZ44S equivalent, key selection considerations include its D2PAK thermal performance (R_thJC = 1.0 °C/W), gate charge profile (Q_g = 67 nC), body diode recovery (t_rr = 120–180 ns), and RoHS-compliant lead-free variants (e.g., SiHFZ44S-GE3).

Technical Context

The IRFZ44S employs third-generation silicon process technology to achieve low on-resistance per die area while maintaining rugged unclamped inductive switching capability. Its gate threshold voltage (2.0–4.0 V) and transconductance (15 S typical) support standard logic-level gate drive, and its internal source inductance (7.5 nH) is optimized for high dI/dt operation up to 250 A/μs.

Thermal design centers on the D2PAK's low junction-to-case resistance (1.0 °C/W), enabling 150 W power dissipation at T_C = 25 °C. The device supports repetitive avalanche operation with E_AS = 100 mJ under defined test conditions (V_DD = 25 V, L = 44 μH, R_g = 25 Ω), and its peak diode recovery dV/dt rating is 4.5 V/ns.

Key Specifications

Pinout & Package

D2PAK (TO-263) surface-mount package with exposed thermal pad on underside; 3-pin configuration (G, D, S) arranged in G–D–S order across the leadframe. Thermal pad must be soldered to large PCB copper area for optimal heat transfer.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STP60NF06 and SiHFZ44S-GE3, the IRFZ44S offers optimized switching-conduction balance in surface-mount form factor, with lower gate charge than STP60NF06 and identical performance to SiHFZ44S-GE3 minus RoHS certification.

Availability

IRFZ44S is available at Aetrix Electronics and suitable for high-current DC-DC converters, motor drive half-bridges, and UPS inverter output stages requiring stable component supply and long-term industrial availability.

Supply support for IRFZ44S 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 and passive components, specializing in high-reliability power MOSFETs, diodes, and optoelectronics for industrial, automotive, and computing markets.

The IRFZ44S belongs to Vishay's third-generation power MOSFET family engineered for high-current, high-efficiency switching in compact surface-mount formats-specifically targeting power conversion and motor control where thermal density and ruggedness are critical.

FAQ

What is the maximum continuous drain current rating for the IRFZ44S at 100 °C case temperature?

The IRFZ44S supports 36 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 validated against actual PCB layout and ambient conditions. The IRFZ44S maintains safe operation up to 175 °C junction temperature, and its R_DS(on) increases predictably with temperature per the normalized on-resistance curve.

Does the IRFZ44S have a built-in body diode, and what are its key recovery parameters?

Yes, the IRFZ44S integrates a parasitic body diode inherent to its vertical N-channel MOSFET structure. Key recovery parameters include reverse recovery time t_rr = 120–180 ns, reverse recovery charge Q_rr = 530–800 nC, and peak diode recovery dV/dt = 4.5 V/ns. These values are measured at T_J = 25 °C, I_F = 51 A, and dI/dt = 100 A/μs, and directly impact switching loss and voltage overshoot in freewheeling applications.

Can the IRFZ44S be driven directly by a 3.3 V microcontroller GPIO pin?

No-the IRFZ44S is not a logic-level MOSFET. Its gate threshold voltage range is 2.0–4.0 V, but full enhancement to R_DS(on) = 0.028 Ω requires V_GS = 10 V. Driving it with only 3.3 V results in high on-resistance (>0.1 Ω), excessive conduction loss, and thermal runaway risk. A dedicated gate driver (e.g., TC4420) or level-shifting circuit is required for reliable operation of the IRFZ44S.

What is the thermal resistance from junction to case (R_thJC) for the IRFZ44S, and how does it affect heatsink design?

The IRFZ44S has a maximum junction-to-case thermal resistance R_thJC of 1.0 °C/W, measured from die to the D2PAK's exposed thermal pad. This low value enables efficient heat transfer to an external heatsink or PCB copper plane. For example, at 100 W power dissipation, the junction-to-case temperature rise is only 100 °C-so with a 25 °C ambient and 1.5 °C/W heatsink + interface resistance, T_J remains within the 175 °C limit. Proper soldering of the thermal pad is essential to achieve this spec for the IRFZ44S.

Is the IRFZ44S suitable for avalanche-rated operation, and under what conditions is E_AS = 100 mJ valid?

Yes, the IRFZ44S is characterized for single-pulse avalanche energy E_AS = 100 mJ, verified per JEDEC JESD24-1. This rating applies under specific test conditions: V_DD = 25 V, starting T_J = 25 °C, L = 44 μH, R_g = 25 Ω, and I_AS = 51 A. Repetitive avalanche is not guaranteed. Designers must ensure pulse width and duty cycle remain within safe operating area limits shown in Figure 7 to avoid cumulative damage to the IRFZ44S.