Vishay Siliconix SI7434DP-T1-E3

Overview

SI7434DP-T1-E3 from Vishay Siliconix is an N-channel 250 V (D-S) TrenchFET® power MOSFET in PowerPAK® SO-8 package, optimized for PWM switching with R_DS(on) = 0.155 Ω @ V_GS = 10 V, Q_g = 34 nC, and continuous drain current I_D = 3.8 A at T_A = 25 °C. It serves as a primary-side switch in telecom power supplies and miniature power modules.

For engineers reviewing the SI7434DP-T1-E3 datasheet, SI7434DP-T1-E3 pinout, SI7434DP-T1-E3 application, or SI7434DP-T1-E3 equivalent, key selection criteria include avalanche-rated ruggedness, 100% R_g testing, lead(Pb)-free/halogen-free compliance, and thermal performance matching DPAK while retaining SO-8 footprint compatibility.

Technical Context

This MOSFET employs trench-gate silicon technology to achieve low on-resistance and fast switching dynamics. Its gate charge profile (Q_g = 34 nC typ., Q_gd = 10.5 nC) supports high-frequency PWM operation up to 500 kHz in hard-switched topologies, with turn-off delay t_d(off) = 47–70 ns and fall time t_f = 19–30 ns under standard test conditions.

The device features integrated body diode with V_SD = 0.75–1.2 V @ I_S = 2.8 A and reverse recovery time t_rr = 100–150 ns, enabling use in synchronous rectification and flyback snubber circuits. Junction-to-case thermal resistance R_thJC = 1.5–1.8 °C/W ensures efficient heat transfer to PCB copper when mounted on recommended land patterns.

Key Specifications

Pinout & Package

Package: PowerPAK® SO-8 (leadless, same footprint as standard SO-8; dimensions 6.15 mm × 5.15 mm × 1.04 mm; exposed drain pad on bottom for thermal conduction).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar N-channel 250 V MOSFET applications.

Compared with STP2NK25Z and IRF640NPBF, SI7434DP-T1-E3 delivers optimal balance of SO-8 footprint compatibility, 3.8 A current capability, and DPAK-equivalent thermal performance-enabling drop-in replacement in space-constrained telecom modules without layout changes or thermal derating.

Availability

SI7434DP-T1-E3 is available at Aetrix Electronics and suitable for telecom power supplies, distributed power architectures, and miniature power modules requiring stable component supply, RoHS-compliant sourcing, and long-term lifecycle support.

Supply support for SI7434DP-T1-E3 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 power MOSFETs, diodes, and optoelectronics with vertical manufacturing and rigorous reliability testing.

The SI7434DP-T1-E3 belongs to Vishay's TrenchFET® PowerPAK® SO-8 family, engineered specifically for high-efficiency, high-density AC-DC and DC-DC conversion in telecom and industrial power systems.

FAQ

What is the maximum gate-source voltage rating for SI7434DP-T1-E3?

The absolute maximum gate-source voltage (V_GS) for SI7434DP-T1-E3 is ±20 V. Exceeding this rating risks permanent gate oxide damage. The typical gate threshold voltage (V_GS(th)) ranges from 2 V to 4 V, and the device is fully enhanced at V_GS = 10 V. For reliable operation, gate drive circuits must limit transient overshoot using clamping diodes or RC snubbers, especially in high-noise industrial environments where SI7434DP-T1-E3 is commonly deployed.

Does SI7434DP-T1-E3 have avalanche capability, and how is it specified?

Yes, SI7434DP-T1-E3 is fully avalanche rated with I_AS = 13 A and E_AS = 8.4 mJ (single pulse, L = 1 mH). This rating is production-tested per JEDEC JESD24-1, not just design-guaranteed. The avalanche capability allows SI7434DP-T1-E3 to safely absorb inductive energy during switching transients in unclamped topologies like flyback converters-eliminating the need for external snubber networks and improving system reliability in telecom power supplies where SI7434DP-T1-E3 is frequently used.

What is the thermal resistance from junction to ambient for SI7434DP-T1-E3 under standard mounting conditions?

The maximum steady-state junction-to-ambient thermal resistance (R_thJA) for SI7434DP-T1-E3 is 65 °C/W when mounted on a 1" × 1" FR4 board per JEDEC JESD51-3. With optimized PCB layout-including ≥0.3 in² spreading copper on the drain pad-R_thJA improves to ~35 °C/W. This thermal performance matches DPAK packages while retaining SO-8 footprint compatibility, making SI7434DP-T1-E3 ideal for thermally constrained miniature power modules where board space is limited but power density is critical.

Can SI7434DP-T1-E3 be used as a direct replacement for standard SO-8 MOSFETs on existing PCBs?

Yes, SI7434DP-T1-E3 uses the identical SO-8 footprint and pinout (G, S, S, S, D, D, D, D), enabling direct replacement on legacy SO-8 land patterns. However, its PowerPAK® SO-8 package has an exposed drain pad on the bottom that requires solder connection to PCB copper for optimal thermal performance. While functional operation is guaranteed without modification, thermal performance improves significantly when the drain pad is connected to ≥0.3 in² of copper-making SI7434DP-T1-E3 a true drop-in upgrade for designs needing higher current or lower thermal resistance than standard SO-8 devices.

What are the gate charge characteristics of SI7434DP-T1-E3, and how do they impact switching performance?

SI7434DP-T1-E3 has total gate charge Q_g = 34 nC (typ.), gate-drain charge Q_gd = 10.5 nC, and gate-source charge Q_gs = 6.8 nC at V_DS = 100 V and V_GS = 10 V. These values enable clean, fast switching with t_d(on) = 16–25 ns and t_f = 19–30 ns, supporting PWM frequencies up to 500 kHz. The low Q_gd/Q_g ratio (~0.31) reduces Miller plateau duration, minimizing shoot-through risk in half-bridge configurations-critical for high-efficiency operation in telecom power supplies where SI7434DP-T1-E3 is widely applied.