Infineon Technologies IRL3705ZSPBF

Overview

IRL3705ZSPBF from Infineon Technologies is a logic-level N-channel HEXFET® Power MOSFET in D²PAK (TO-263) package, rated for 55V V_DSS, 8.0 mΩ R_DS(on) at V_GS = 10 V, and 75 A continuous drain current at T_C = 25°C. It features 175°C junction temperature rating, fast switching (t_r = 240 ns, t_f = 83 ns), and tested repetitive avalanche capability up to T_jmax, enabling high-efficiency DC-DC conversion and motor drive stages.

For engineers reviewing the IRL3705ZSPBF datasheet, IRL3705ZSPBF pinout, IRL3705ZSPBF application, or IRL3705ZSPBF equivalent, key selection criteria include its low gate threshold (1.0–3.0 V), ultra-low on-resistance per silicon area, body diode recovery performance (t_rr = 16–24 ns, Q_rr = 7.4–11 nC), and thermal robustness under pulsed load conditions.

Technical Context

This MOSFET employs advanced planar silicon processing to minimize conduction losses while maintaining rugged unclamped inductive switching behavior. Its gate charge profile (Q_g = 40–60 nC, Q_gd = 21 nC) supports efficient 5 V logic-level drive and reduces Miller-induced turn-off delay in hard-switched topologies.

The device integrates a co-packaged body diode with V_SD ≤ 1.3 V at 43 A and exhibits controlled reverse recovery (Q_rr, t_rr) suitable for synchronous rectification and H-bridge motor control. Thermal design is enabled by R_θJC = 1.14 °C/W and validated transient impedance curves up to 100 ms pulse width.

Key Specifications

Pinout & Package

IRL3705ZSPBF is housed in a surface-mount D²PAK (TO-263) package with exposed drain pad for thermal enhancement. The three terminals are arranged in standard G-S-D order (left-to-right when viewing component side-up, lead side down).

Key Features

Applications

Equivalent & Alternatives

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

Compared with STP75NF75 and IRF3205PbF, IRL3705ZSPBF delivers superior thermal resistance (R_θJC = 1.14 °C/W), verified repetitive avalanche capability, and lower gate charge-making it optimal for high-density, high-reliability 48 V power systems where layout space and fault tolerance are constrained.

Availability

IRL3705ZSPBF is available at Aetrix Electronics and suitable for DC-DC converters, BLDC motor inverters, automotive body control modules, and industrial solenoid drivers requiring stable component supply across multi-year production cycles.

Supply support for IRL3705ZSPBF 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 electronics, and industrial control ICs, with global manufacturing and qualification infrastructure.

The IRL3705ZSPBF belongs to Infineon's HEXFET® logic-level MOSFET product line, engineered specifically for high-current, low-voltage switching applications where gate drive simplicity, thermal resilience, and avalanche ruggedness are essential.

FAQ

Is IRL3705ZSPBF suitable for 3.3 V microcontroller gate drive?

Yes - its gate threshold voltage (V_GS(th)) ranges from 1.0 V to 3.0 V, and it achieves R_DS(on) ≤ 11 mΩ at V_GS = 4.5 V. While full enhancement occurs at 5 V, many designs successfully operate it with 3.3 V drive in lower-current applications (<20 A), provided gate charge time and switching loss are acceptable.

What is the maximum recommended PCB copper area for thermal relief?

For optimal R_θJC = 1.14 °C/W, the D²PAK drain pad must be connected to ≥250 mm² of 2 oz copper on the primary layer, with ≥4 thermal vias (0.3 mm diameter, filled or plated) connecting to inner/ground planes. Larger copper areas further reduce case temperature but yield diminishing returns beyond 400 mm².

Does IRL3705ZSPBF have a specified SOA curve for linear-mode operation?

No - the datasheet provides only unclamped inductive avalanche SOA (Figure 8) and does not specify safe operating area for linear (triode) region biasing. It is intended for switching applications only; linear-mode use risks thermal runaway due to positive R_DS(on) temperature coefficient above 100°C.

Can the body diode be used for synchronous rectification in a buck converter?

Yes - the integrated body diode has t_rr = 16–24 ns and Q_rr = 7.4–11 nC, making it viable for synchronous rectification at ≤300 kHz. However, external Schottky diodes or dedicated synchronous MOSFETs offer lower forward drop and better recovery in high-frequency, high-efficiency designs.