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

Vishay Siliconix SI4866DY-T1-E3

Name: SI4866DY-T1-E3
Brand: Vishay Siliconix
SKU: SI4866DY-T1-E3
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: SI4866DY-T1-E3

Manufacturer:: Vishay Siliconix

Category:: FETs, MOSFETs

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

Datasheet:: SI4866DY-T1-E3.pdf

Description:: MOSFET N-CH 12V 11A 8SO

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Product details

Overview

SI4866DY-T1-E3 from Vishay Siliconix is an N-channel TrenchFET® power MOSFET optimized for synchronous rectification in high-efficiency DC-DC converters, featuring 12 V V_DS, 0.0055 Ω R_DS(on) at 4.5 V V_GS, and 17 A continuous drain current at T_J = 150 °C. It uses SO-8 packaging and supports PWM switching with low gate charge (21–30 nC) and fast switching times (t_d(on) = 28–42 ns).

For engineers reviewing the SI4866DY-T1-E3 datasheet, SI4866DY-T1-E3 pinout, SI4866DY-T1-E3 application, or SI4866DY-T1-E3 equivalent, key selection criteria include its low R_DS(on) at 2.5 V and 4.5 V gate drive, integrated body diode performance (V_SD = 0.70–1.1 V), thermal resistance (R_thJA = 67 °C/W), and Pb-free/halogen-free compliance per IEC 61249-2-21.

Technical Context

This MOSFET employs trench-gate silicon technology to achieve reduced gate charge and fast switching transitions, enabling high-frequency operation in synchronous buck topologies. Its threshold voltage (V_GS(th) = 0.6 V typ.) and low R_DS(on) at 2.5 V (0.008 Ω) support direct drive from low-voltage controllers and microcontrollers.

The device integrates a robust body diode with reverse recovery time (t_rr = 60–90 ns) and forward voltage (V_SD = 0.70–1.1 V at I_S = 2.7 A), making it suitable for bidirectional current paths in synchronous rectification. Thermal design is supported by validated junction-to-foot (R_thJF = 15–19 °C/W) and junction-to-ambient (R_thJA = 67–80 °C/W) metrics under standard FR4 mounting.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	12 V - Maximum blocking voltage compatible with 12 V input rails and point-of-load systems
R_DS(on) @ 4.5 V	0.0055 Ω - Enables <100 mW conduction loss at 17 A, critical for high-current POL efficiency
R_DS(on) @ 2.5 V	0.008 Ω - Supports direct interface with 2.5 V logic-level gate drivers without level shifting
Q_g	21–30 nC - Low total gate charge reduces driver power loss and enables >1 MHz switching
t_d(on)/t_f	28–42 ns / 35–53 ns - Fast turn-on/turn-off minimizes overlap loss in synchronous rectifier operation
V_GS(th)	0.6 V - Ensures reliable enhancement-mode turn-on with margin below typical controller output low levels
V_SD	0.70–1.1 V - Low body diode forward voltage reduces reverse conduction loss during dead-time

Pinout & Package

SO-8 (MS-012) surface-mount package with exposed drain pad for enhanced thermal dissipation. Dimensions: 4.9 mm × 3.9 mm × 1.5 mm (D × E × A), 1.27 mm pitch.

Pin/Terminal	Circuit Role	Design Meaning
1, 2, 3, 4, 5, 7, 8	Drain (D)	Internally connected to common drain node and exposed thermal pad - primary current path and heat sink interface
6	Gate (G)	Control terminal for MOSFET channel activation - requires low-impedance drive due to Q_g = 21–30 nC
Source (S)	Source (S)	Reference node for gate drive and load return - pins 1–5 and 7–8 are source-connected in parallel configuration

Key Features

Feature	Design Value
TrenchFET® architecture	Enables 0.0055 Ω R_DS(on) at 4.5 V while maintaining 12 V breakdown - balances conduction loss and voltage margin
PWM-optimized switching	Low Q_gd/Q_g ratio (3.5/21–30 nC) minimizes Miller-induced switching delay and improves hard-switching robustness
100 % R_g tested	Guarantees gate resistance between 1.5–3.9 Ω - ensures consistent turn-on timing across production lots
Halogen-free & Pb-free	Complies with IEC 61249-2-21 and RoHS - meets environmental requirements for industrial and telecom end equipment

Applications

Synchronous Rectifier	Point-of-Load Buck Converter
Use Scenario: Secondary-side rectification in isolated DC-DC converters (e.g., 48 V to 12 V telecom supplies). IC Role / Device Role / Timing Role: Replaces Schottky diode to reduce conduction loss and improve efficiency at high current (>10 A). Use Value: Achieves >95 % efficiency at 17 A due to 0.0055 Ω R_DS(on) and low V_SD (0.70 V), cutting thermal load vs. discrete diodes.	Use Scenario: High-current step-down regulation in server VRMs and FPGA power delivery. IC Role / Device Role / Timing Role: Low-side switch in synchronous buck stage operating at 300–1000 kHz. Use Value: Enables compact layout with SO-8 footprint and supports 17 A continuous current without forced air cooling.
USB-C Power Delivery	Industrial Motor Drive H-Bridge
Use Scenario: Output rectification and overcurrent protection in 20–100 W USB PD adapters. IC Role / Device Role / Timing Role: Synchronous rectifier paired with Si4865DY or similar high-side counterpart. Use Value: Meets stringent no-load and light-load efficiency targets via low R_DS(on) at 2.5 V gate drive.	Use Scenario: Half-bridge leg in 12 V BLDC motor control for factory automation actuators. IC Role / Device Role / Timing Role: Low-side switch handling bidirectional current during PWM commutation. Use Value: Body diode t_rr = 60–90 ns and V_SD = 0.70–1.1 V minimize shoot-through risk and conduction loss during freewheeling.

Synchronous Rectifier

Point-of-Load Buck Converter

Use Scenario: Secondary-side rectification in isolated DC-DC converters (e.g., 48 V to 12 V telecom supplies).

IC Role / Device Role / Timing Role: Replaces Schottky diode to reduce conduction loss and improve efficiency at high current (>10 A).

Use Value: Achieves >95 % efficiency at 17 A due to 0.0055 Ω R_DS(on) and low V_SD (0.70 V), cutting thermal load vs. discrete diodes.

Use Scenario: High-current step-down regulation in server VRMs and FPGA power delivery.

IC Role / Device Role / Timing Role: Low-side switch in synchronous buck stage operating at 300–1000 kHz.

Use Value: Enables compact layout with SO-8 footprint and supports 17 A continuous current without forced air cooling.

USB-C Power Delivery

Industrial Motor Drive H-Bridge

Use Scenario: Output rectification and overcurrent protection in 20–100 W USB PD adapters.

IC Role / Device Role / Timing Role: Synchronous rectifier paired with Si4865DY or similar high-side counterpart.

Use Value: Meets stringent no-load and light-load efficiency targets via low R_DS(on) at 2.5 V gate drive.

Use Scenario: Half-bridge leg in 12 V BLDC motor control for factory automation actuators.

IC Role / Device Role / Timing Role: Low-side switch handling bidirectional current during PWM commutation.

Use Value: Body diode t_rr = 60–90 ns and V_SD = 0.70–1.1 V minimize shoot-through risk and conduction loss during freewheeling.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
Si4865DY-T1-E3	Higher R_DS(on) (0.0075 Ω @ 4.5 V), same SO-8 package and 12 V rating	Marginally lower efficiency in high-current POL; identical pinout and drive requirements	Select when cost sensitivity outweighs 10–15 mΩ R_DS(on) penalty and thermal budget allows
IRF7478PBF	12 V V_DS, 0.0065 Ω R_DS(on) @ 4.5 V, higher Q_g (34 nC), SO-8 package	Slower switching (t_d(off) ≈ 150 ns) increases switching loss above 500 kHz	Prefer for legacy designs using IR's gate drive profiles; avoid in >1 MHz high-efficiency apps

Compared with SI4866DY-T1-E3, Si4865DY-T1-E3 trades 1.2 mΩ higher R_DS(on) for lower unit cost, while IRF7478PBF offers similar on-resistance but requires stronger gate drive and yields higher switching loss - SI4866DY-T1-E3 delivers optimal balance of conduction efficiency, speed, and thermal performance in space-constrained POL designs.

Availability

SI4866DY-T1-E3 is available at Aetrix Electronics and suitable for synchronous rectifiers, point-of-load buck converters, and USB-C power delivery systems requiring stable component supply, Pb-free compliance, and high-reliability SO-8 MOSFETs.

Supply support for SI4866DY-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 emphasis on reliability, thermal performance, and application-specific optimization.

The Si4866DY product line targets high-efficiency DC-DC conversion in computing, telecom, and industrial power systems, with design focus on low-voltage gate drive compatibility, fast switching, and thermally robust SO-8 packaging.

FAQ

What is the maximum continuous drain current for SI4866DY-T1-E3 at 70 °C ambient temperature?

The SI4866DY-T1-E3 supports 14 A continuous drain current at T_A = 70 °C with proper PCB copper area (1" × 1" FR4). This rating assumes steady-state thermal conditions and accounts for R_thJA = 67–80 °C/W. Derating is required above 70 °C ambient, and peak pulsed current capability remains ±50 A for short durations (≤300 µs).

Does SI4866DY-T1-E3 have a guaranteed gate threshold voltage range?

Yes, the SI4866DY-T1-E3 has a specified gate threshold voltage V_GS(th) of 0.6 V (typical) at V_DS = V_GS and I_D = 250 µA, with no min/max range published. The device is designed for reliable turn-on with gate voltages ≥2.5 V, and its low 0.6 V typical threshold supports robust operation even with marginal gate drive margins.

Can SI4866DY-T1-E3 be used in a 2.5 V gate-drive application?

Yes, the SI4866DY-T1-E3 is explicitly characterized at V_GS = 2.5 V, delivering R_DS(on) = 0.008 Ω (max) at I_D = 14 A. Its 0.6 V typical V_GS(th) and low gate charge enable full enhancement with 2.5 V logic-level drivers - no level shifter required in compatible controller designs.

What is the thermal resistance from junction to foot (R_thJF) for SI4866DY-T1-E3?

The SI4866DY-T1-E3 has a maximum junction-to-foot thermal resistance R_thJF of 19 °C/W under steady-state conditions. This value reflects conduction through the exposed drain pad into the PCB copper, and is critical for estimating die temperature when using internal layer copper pours or thermal vias beneath the SO-8 footprint.

Is SI4866DY-T1-E3 halogen-free and RoHS compliant?

Yes, SI4866DY-T1-E3 is both halogen-free per IEC 61249-2-21 and RoHS-compliant (Pb-free). The "-E3" suffix denotes lead-free termination and halogen-free construction, verified per Vishay's material declarations and manufacturing process controls.

SI4866DY-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):: 12 V

Current - Continuous Drain (Id) @ 25°C:: 11A (Ta)

Drive Voltage (Max Rds On, Min Rds On):: 2.5V, 4.5V

Rds On (Max) @ Id, Vgs:: 5.5mOhm @ 17A, 4.5V

Vgs(th) (Max) @ Id:: 600mV @ 250µA (Min)

Gate Charge (Qg) (Max) @ Vgs:: 30 nC @ 4.5 V

Vgs (Max):: ±8V

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

FET Feature:: -

Power Dissipation (Max):: 1.6W (Ta)

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-SOIC

SI4866DY-T1-E3 FAQ

1.How can I place an order for SI4866DY-T1-E3 through Aetrix?

Please submit a Request for Quotation (RFQ) for SI4866DY-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 SI4866DY-T1-E3 reliable?

The price and inventory of SI4866DY-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 SI4866DY-T1-E3 is usually 5 days.

3.What payment methods are accepted for SI4866DY-T1-E3?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SI4866DY-T1-E3 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for SI4866DY-T1-E3?

SI4866DY-T1-E3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your SI4866DY-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 SI4866DY-T1-E3?

For technical support, including SI4866DY-T1-E3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SI4866DY-T1-E3 requirements.

6.How does Aetrix verify that SI4866DY-T1-E3 is sourced from the original manufacturer or authorized distributors?

All SI4866DY-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 SI4866DY-T1-E3 meets industry standards.

7.What is the process for return or replacement of SI4866DY-T1-E3?

All SI4866DY-T1-E3 units undergo pre-shipment inspection (PSI). If there is an issue with SI4866DY-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 SI4866DY-T1-E3 part is unused and in its original packaging.

Return procedure for SI4866DY-T1-E3:

1.Submit a request within 90 days.

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

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