Vishay Siliconix IRFI9Z34G

Overview

IRFI9Z34G from Vishay Siliconix is a P-channel enhancement-mode power MOSFET in TO-220 FULLPAK package, rated for -60 V V_DS, 0.14 Ω R_DS(on) at V_GS = -10 V, and -12 A continuous drain current at T_C = 25 °C. It delivers high-voltage isolation (2.5 kV_RMS, 60 s), 175 °C operating junction temperature, and robust avalanche capability (370 mJ single-pulse), making it suitable for industrial DC-DC converters and high-side switch circuits requiring thermal reliability and creepage safety.

For engineers reviewing the IRFI9Z34G datasheet, IRFI9Z34G pinout, IRFI9Z34G application, or IRFI9Z34G equivalent, this page provides verified technical context, validated pin configuration, real-world application mappings, and two confirmed alternative parts with documented functional and parametric differences - all grounded in Vishay's official S21-0975-Rev. D specification.

Technical Context

The IRFI9Z34G is a third-generation silicon-based P-channel MOSFET optimized for high-voltage, medium-current switching in isolated topologies. Its TO-220 FULLPAK construction integrates a molded insulating barrier delivering 2.5 kV_RMS isolation and 4.8 mm sink-to-lead creepage - eliminating external insulation hardware in commercial-industrial designs.

It features low thermal resistance (R_thJC = 3.6 °C/W), dynamic dV/dt rating (-4.5 V/ns), and fast switching performance (t_d(on) = 18 ns, t_f = 58 ns) enabled by 34 nC total gate charge and 100 pF Crss. The body diode supports -12 A continuous conduction with 100–200 ns reverse recovery time and 0.28–0.52 μC Q_rr.

Key Specifications

Pinout & Package

IRFI9Z34G uses the TO-220 FULLPAK package: an isolated, surface-mountable variant of TO-220 with integral high-dielectric molding compound, 4.8 mm creepage, and tab-isolated drain connection. Mounting requires only one screw or clip to heatsink; no additional insulation needed.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IRF9Z34NPbF and STP9PF55, the IRFI9Z34G uniquely combines certified 2.5 kV_RMS isolation, 4.8 mm creepage, and 370 mJ avalanche energy - making it the only option among the three qualified for reinforced insulation in industrial power supplies without layout or BOM changes.

Availability

IRFI9Z34G is available at Aetrix Electronics and suitable for industrial motor control, AC/DC auxiliary power supplies, and telecom DC-DC converters requiring stable component supply, long-term lifecycle support, and certified high-voltage isolation.

Supply support for IRFI9Z34G 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 demanding industrial, automotive, and computing applications.

The IRFI9Z34G belongs to Vishay's third-generation high-voltage P-channel MOSFET family, engineered specifically for isolated high-side switching in industrial power conversion where creepage, thermal resilience, and avalanche ruggedness are design-critical.

FAQ

What is the maximum continuous drain current rating for IRFI9Z34G at 100 °C case temperature?

The IRFI9Z34G supports -8.5 A continuous drain current at T_C = 100 °C, as specified in the Absolute Maximum Ratings table. This derating reflects its 0.28 W/°C linear derating factor from the 42 W maximum power dissipation at 25 °C. Designers must verify heatsink thermal resistance to maintain T_C ≤ 100 °C under full-load conditions to sustain this current level reliably in the IRFI9Z34G.

Does IRFI9Z34G require external isolation hardware when mounted to a heatsink?

No, the IRFI9Z34G does not require external isolation hardware. Its TO-220 FULLPAK package incorporates a high-dielectric molding compound that provides 2.5 kV_RMS isolation (60 s) and 4.8 mm sink-to-lead creepage - equivalent to a 100 µm mica barrier used with standard TO-220 devices. This allows direct mechanical mounting to a conductive heatsink without insulating pads or washers in the IRFI9Z34G design.

What is the gate-source threshold voltage range for IRFI9Z34G?

The gate-source threshold voltage (V_GS(th)) for IRFI9Z34G is specified from -2.0 V to -4.0 V at V_DS = V_GS and I_D = 250 µA. This range confirms its enhancement-mode P-channel behavior and ensures reliable turn-on with standard -10 V gate drive while maintaining noise immunity against spurious turn-on at -2 V. The IRFI9Z34G operates predictably across this threshold window in real-world gate driver implementations.

Can IRFI9Z34G be used in avalanche mode for inductive load switching?

Yes, the IRFI9Z34G is rated for repetitive avalanche operation with I_AR = -12 A and E_AR = 4.2 mJ, and single-pulse avalanche energy of 370 mJ. Its datasheet includes validated unclamped inductive test waveforms (Fig. 12a–12b) confirming safe operation under inductive turn-off stress. When properly heatsinked and within SOA limits, the IRFI9Z34G can replace external snubbers in solenoid, relay, and motor brake circuits.

What is the typical reverse recovery time of the body diode in IRFI9Z34G?

The body diode reverse recovery time (t_rr) for IRFI9Z34G is 100–200 ns at T_J = 25 °C, I_F = -18 A, and dI/dt = 100 A/µs. This fast recovery characteristic minimizes switching losses and cross-conduction risk in half-bridge or synchronous rectifier configurations. The associated Q_rr of 0.28–0.52 µC further supports efficient freewheeling in the IRFI9Z34G's intended applications.