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Home > Products > Discrete Semiconductor Products > Transistors > FETs, MOSFETs > FETs, MOSFETs

Vishay Siliconix SI4418DY-T1-E3

Name: SI4418DY-T1-E3
Brand: Vishay Siliconix
SKU: SI4418DY-T1-E3
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: SI4418DY-T1-E3

Manufacturer:: Vishay Siliconix

Category:: FETs, MOSFETs

Package:: 8-SOIC (0.154", 3.90mm Width)

Datasheet:: SI4418DY-T1-E3.pdf

Description:: MOSFET N-CH 200V 2.3A 8SO

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Product details

Overview

SI4418DY-T1-E3 from Vishay Siliconix is an N-channel 200-V TrenchFET® power MOSFET in SO-8 package, rated for 3 A continuous drain current at 25 °C, with R_DS(on) = 0.130 Ω at V_GS = 10 V and 3 A - designed for primary-side switching in offline AC/DC converters.

For engineers reviewing the SI4418DY-T1-E3 datasheet, SI4418DY-T1-E3 pinout, SI4418DY-T1-E3 application, or SI4418DY-T1-E3 equivalent, key selection criteria include its 200-V V_DS, low gate charge (20–30 nC), robust avalanche rating (E_AS = 1.8 mJ), thermal resistance (R_thJA = 71 °C/W steady-state), and Pb-free RoHS-compliant construction.

Technical Context

This MOSFET employs Vishay's TrenchFET® process to achieve low on-resistance and fast switching performance. Its gate threshold voltage (V_GS(th) = 2–4 V) ensures reliable turn-on with standard logic-level drivers, while the 100 % R_g tested specification guarantees consistent gate resistance (1–3.4 Ω) across production lots.

The device supports unclamped inductive switching with a rated single-pulse avalanche energy of 1.8 mJ and withstands 200-V drain-source blocking. Its SO-8 footprint enables surface-mount integration into compact power stages without requiring heatsinking for moderate-power applications.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	200 V - supports primary-side switching in universal-input (85–265 V_AC) offline flyback and forward converters.
R_DS(on)	0.130 Ω @ V_GS = 10 V, I_D = 3 A - limits conduction loss to ≤1.17 W at full rated current.
Q_g	20–30 nC - enables efficient 100-kHz+ switching with moderate gate drive strength (e.g., 1-A peak driver).
E_AS	1.8 mJ - provides margin against inductive energy spikes during hard-switching or fault conditions.
R_thJA	71 °C/W (steady-state) - allows ~2.5 W dissipation at 25 °C ambient before reaching 150 °C junction limit.
I_D (cont)	3 A @ T_A = 25 °C - defines maximum DC load current under standard PCB mounting (1" × 1" FR4).
V_GS(th)	2–4 V - ensures compatibility with 3.3 V and 5 V microcontroller GPIO or dedicated gate drivers.

Pinout & Package

SO-8 surface-mount package with exposed drain pad for enhanced thermal performance. Pin 1–8 arranged as per top-view diagram: pins 1–4 = S, S, D, D; pins 5–8 = D, D, G, D (drain-connected pins 3, 4, 5, 6, 8; source pins 1, 2; gate pin 7).

Pin/Terminal	Circuit Role	Design Meaning
1, 2	Source	Low-side return path; tied together internally and externally for lowest source inductance.
3, 4, 5, 6, 8	Drain	High-voltage power node; multiple pins reduce current density and improve thermal conduction to PCB copper.
7	Gate	Control input; requires <20 nC charge for full enhancement; sensitive to ESD (±20 V max rating).

Key Features

Feature	Design Value
TrenchFET® technology	Enables lower R_DS(on) and higher cell density than planar MOSFETs, improving power density in space-constrained SMPS designs.
100 % R_g tested	Ensures gate resistance between 1–3.4 Ω across all units, enabling predictable gate drive timing and reduced layout sensitivity.
Halogen-free construction	Complies with IEC 61249-2-21, supporting environmentally regulated industrial and consumer end-equipment.
Lead (Pb)-free (RoHS)	Meets EU RoHS Directive 2011/65/EU and JEDEC J-STD-020 reflow profile requirements for lead-free assembly.

Applications

Offline Flyback Converter Primary Switch	DC-DC Boost Pre-regulator
Use Scenario: High-efficiency 12–24 W AC/DC adapter with universal input (85–265 V_AC) and 12 V output. IC Role / Device Role / Timing Role: Primary-side power switch operating at 65–100 kHz, driven by UC3842 or similar PWM controller. Use Value: 0.130 Ω R_DS(on) minimizes conduction loss; 200-V rating accommodates reflected output voltage plus leakage spike margin.	Use Scenario: 48 V bus pre-regulator stepping up from 24 V battery in telecom power shelf. IC Role / Device Role / Timing Role: High-side boost switch in continuous conduction mode (CCM), switching at 200 kHz. Use Value: Low Q_g (20–30 nC) reduces gate drive loss; SO-8 thermal design supports 2.5 W dissipation without heatsink.
LED Driver High-Side Switch	Industrial Solenoid Driver
Use Scenario: Constant-current LED string driver for street lighting, powered from rectified 230 V_AC. IC Role / Device Role / Timing Role: Primary-side switch in buck-derived topology, operating in discontinuous conduction mode (DCM). Use Value: 1.8 mJ E_AS withstands inductive kickback from transformer leakage; V_GS(th) range ensures stable turn-on with 5 V gate drive.	Use Scenario: 24 V DC solenoid control module in factory automation PLC I/O card. IC Role / Device Role / Timing Role: High-side load switch controlled by microcontroller GPIO via level-shifting circuit. Use Value: 200-V V_DS provides >4× overvoltage margin against 24 V supply transients; SO-8 footprint simplifies PCB routing.

Offline Flyback Converter Primary Switch

DC-DC Boost Pre-regulator

Use Scenario: High-efficiency 12–24 W AC/DC adapter with universal input (85–265 V_AC) and 12 V output.

IC Role / Device Role / Timing Role: Primary-side power switch operating at 65–100 kHz, driven by UC3842 or similar PWM controller.

Use Value: 0.130 Ω R_DS(on) minimizes conduction loss; 200-V rating accommodates reflected output voltage plus leakage spike margin.

Use Scenario: 48 V bus pre-regulator stepping up from 24 V battery in telecom power shelf.

IC Role / Device Role / Timing Role: High-side boost switch in continuous conduction mode (CCM), switching at 200 kHz.

Use Value: Low Q_g (20–30 nC) reduces gate drive loss; SO-8 thermal design supports 2.5 W dissipation without heatsink.

LED Driver High-Side Switch

Industrial Solenoid Driver

Use Scenario: Constant-current LED string driver for street lighting, powered from rectified 230 V_AC.

IC Role / Device Role / Timing Role: Primary-side switch in buck-derived topology, operating in discontinuous conduction mode (DCM).

Use Value: 1.8 mJ E_AS withstands inductive kickback from transformer leakage; V_GS(th) range ensures stable turn-on with 5 V gate drive.

Use Scenario: 24 V DC solenoid control module in factory automation PLC I/O card.

IC Role / Device Role / Timing Role: High-side load switch controlled by microcontroller GPIO via level-shifting circuit.

Use Value: 200-V V_DS provides >4× overvoltage margin against 24 V supply transients; SO-8 footprint simplifies PCB routing.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
STP2NK20Z	200 V, 2 A, R_DS(on) = 0.22 Ω @ 10 V - higher on-resistance and lower current rating.	Suitable only for ≤15 W flyback designs due to lower I_D and higher conduction loss.	Select when cost sensitivity outweighs efficiency needs and board space permits larger thermal relief.
IRF640NPBF	200 V, 18 A, R_DS(on) = 0.18 Ω @ 10 V - TO-220 package, higher current but larger footprint and worse thermal resistance.	Requires heatsink for >1.5 W dissipation; not suitable for high-density SMT layouts.	Choose for legacy through-hole designs or where higher peak current capability is required despite larger size.

Compared with STP2NK20Z and IRF640NPBF, the SI4418DY-T1-E3 delivers optimal balance of low R_DS(on), compact SO-8 packaging, and proven avalanche ruggedness - making it preferred for modern SMT-based, medium-power primary-side switching where thermal and space constraints are critical.

Availability

SI4418DY-T1-E3 is available at Aetrix Electronics and suitable for offline AC/DC adapters, industrial DC-DC pre-regulators, and LED driver primary-side switching requiring stable component supply and long-term manufacturing continuity.

Supply support for SI4418DY-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 MOSFETs, diodes, and optoelectronics with emphasis on reliability, efficiency, and application-specific optimization.

The Si4418DY belongs to Vishay's TrenchFET® Gen III family, engineered for high-voltage, medium-current switching in space-constrained power conversion systems - particularly targeting primary-side regulation in compact, high-efficiency offline converters.

FAQ

What is the maximum continuous drain current for SI4418DY-T1-E3 at 85 °C ambient temperature?

The SI4418DY-T1-E3 supports 2.1 A continuous drain current at T_A = 85 °C, as specified in the Absolute Maximum Ratings table. This derating reflects thermal limitations of the SO-8 package on standard FR4 PCBs; actual usable current depends on copper area, airflow, and layout. The SI4418DY-T1-E3 must be operated within this limit to avoid exceeding the 150 °C maximum junction temperature.

Does SI4418DY-T1-E3 have integrated avalanche ruggedness, and what is its rated energy?

Yes, the SI4418DY-T1-E3 is rated for unclamped inductive switching with a single-pulse avalanche energy (E_AS) of 1.8 mJ at T_J = 25 °C. This value is measured with L = 0.1 mH and is validated per JEDEC standards. The SI4418DY-T1-E3 uses TrenchFET® technology to sustain this energy without failure, providing design margin in flyback and forward converter primary switches.

What is the gate threshold voltage range for SI4418DY-T1-E3, and how does it affect drive compatibility?

The SI4418DY-T1-E3 has a gate threshold voltage (V_GS(th)) range of 2–4 V at I_D = 250 µA. This ensures reliable turn-on with 3.3 V or 5 V logic-level gate drivers, including microcontroller GPIOs with appropriate buffering. The SI4418DY-T1-E3 remains fully enhanced above 6 V, delivering its specified R_DS(on) of 0.142 Ω at V_GS = 6 V and 2.8 A.

Is SI4418DY-T1-E3 compatible with lead-free reflow soldering processes?

Yes, the SI4418DY-T1-E3 is explicitly marked "Lead (Pb)-free" and qualified for standard lead-free reflow profiles per JEDEC J-STD-020. Its SO-8 package meets IPC/JEDEC specifications for moisture sensitivity level (MSL) and thermal cycling endurance. The SI4418DY-T1-E3 may be processed using peak temperatures up to 260 °C without degradation.

How many drain pins does SI4418DY-T1-E3 have in its SO-8 package, and why is this important?

The SI4418DY-T1-E3 has five drain-connected pins (pins 3, 4, 5, 6, and 8) in its SO-8 package. This multi-pin drain configuration lowers effective package inductance and improves thermal conduction from the die to the PCB copper pour. For the SI4418DY-T1-E3, this design directly supports higher switching efficiency and better thermal management in high-frequency power stages.

SI4418DY-T1-E3 Specifications

Product attributes: Attribute value

Manufacturer:: Vishay Siliconix

Series:: TrenchFET®

Package/Case:: 8-SOIC (0.154", 3.90mm Width)

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

FET Type:: N-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 200 V

Current - Continuous Drain (Id) @ 25°C:: 2.3A (Ta)

Drive Voltage (Max Rds On, Min Rds On):: 6V, 10V

Rds On (Max) @ Id, Vgs:: 130mOhm @ 3A, 10V

Vgs(th) (Max) @ Id:: 4V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 30 nC @ 10 V

Vgs (Max):: ±20V

Input Capacitance (Ciss) (Max) @ Vds:: -

FET Feature:: -

Power Dissipation (Max):: 1.5W (Ta)

Operating Temperature:: -55°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-SOIC

SI4418DY-T1-E3 FAQ

1.How can I place an order for SI4418DY-T1-E3 through Aetrix?

Please submit a Request for Quotation (RFQ) for SI4418DY-T1-E3 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for SI4418DY-T1-E3 reliable?

The price and inventory of SI4418DY-T1-E3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SI4418DY-T1-E3 is usually 5 days.

3.What payment methods are accepted for SI4418DY-T1-E3?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SI4418DY-T1-E3 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for SI4418DY-T1-E3?

SI4418DY-T1-E3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your SI4418DY-T1-E3 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for SI4418DY-T1-E3?

For technical support, including SI4418DY-T1-E3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SI4418DY-T1-E3 requirements.

6.How does Aetrix verify that SI4418DY-T1-E3 is sourced from the original manufacturer or authorized distributors?

All SI4418DY-T1-E3 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that SI4418DY-T1-E3 meets industry standards.

7.What is the process for return or replacement of SI4418DY-T1-E3?

All SI4418DY-T1-E3 units undergo pre-shipment inspection (PSI). If there is an issue with SI4418DY-T1-E3, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The SI4418DY-T1-E3 part is unused and in its original packaging.

Return procedure for SI4418DY-T1-E3:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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