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

Vishay Siliconix SI4866BDY-T1-E3

Name: SI4866BDY-T1-E3
Brand: Vishay Siliconix
SKU: SI4866BDY-T1-E3
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: SI4866BDY-T1-E3

Manufacturer:: Vishay Siliconix

Category:: FETs, MOSFETs

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

Datasheet:: SI4866BDY-T1-E3.pdf

Description:: MOSFET N-CH 12V 21.5A 8SO

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Product details

Overview

SI4866BDY-T1-E3 from Vishay Siliconix is an N-channel 12-V TrenchFET® Power MOSFET in SO-8 package, with R_DS(on) = 0.0053 Ω at V_GS = 4.5 V, 21.5 A continuous drain current (T_C = 25 °C), and 29.5 nC total gate charge - optimized for synchronous rectification in high-efficiency DC/DC converters.

For engineers reviewing the SI4866BDY-T1-E3 datasheet, SI4866BDY-T1-E3 pinout, SI4866BDY-T1-E3 application, or SI4866BDY-T1-E3 equivalent, key selection criteria include low-voltage gate drive compatibility (1.8 V–4.5 V), ultra-low on-resistance at logic-level drive, thermal resistance (R_thJA = 40 °C/W typ.), and 100% R_g and UIS tested reliability for point-of-load power stages.

Technical Context

This MOSFET employs trench-gate silicon technology to achieve sub-6 mΩ R_DS(on) at V_GS = 4.5 V while maintaining ±8 V gate-source voltage rating and 12 V drain-source breakdown. Its dynamic parameters - C_iss = 5020 pF, Q_gd = 8.9 nC, and t_f = 9–18 ns - support fast switching in synchronous buck topologies with minimal switching loss.

The device features a robust body diode with V_SD = 0.62–1.1 V at I_S = 2.3 A and t_rr = 50–80 ns, enabling efficient reverse recovery in high-frequency synchronous rectifier operation without external Schottky assistance.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	12 V - supports input rails up to 12 V in POL converters and battery-powered systems
R_DS(on)	0.0053 Ω at V_GS = 4.5 V - enables <100 mW conduction loss at 10 A, critical for >95% efficiency targets
I_D (continuous)	21.5 A at T_C = 25 °C - delivers high current density in compact SO-8 footprint
Q_g	29.5 nC at V_GS = 2.5 V - ensures fast turn-on with low-power gate drivers in 1–3 MHz designs
R_thJA	40 °C/W typical - allows 2.5 W dissipation at ΔT = 100 °C on standard FR4, no heatsink required
V_GS(th)	0.4–1.0 V - guarantees enhancement-mode turn-on with logic-level controllers (e.g., PWM ICs with 1.8 V outputs)
t_rr	50–80 ns - minimizes dead-time losses and EMI in synchronous rectification

Pinout & Package

SO-8 (JEDEC MS-012) surface-mount package, 4.8 mm × 3.9 mm × 1.5 mm profile, with exposed drain pad for thermal enhancement. Pin 1–8 arranged in dual-row configuration; pins 1, 2, 3, 4 and 5, 6, 7, 8 form two parallel source/drain/gate groups per side.

Pin/Terminal	Circuit Role	Design Meaning
1, 2, 3, 4, 6, 7, 8	Drain (D)	Internally paralleled drain terminals - connected to exposed pad; primary heat path and high-current output node
5	Gate (G)	Single gate input - low capacitance (C_iss = 5020 pF) enables clean edge control with minimal ringing
- (exposed pad)	Drain (D)	Thermal and electrical connection to PCB copper - must be soldered to ≥1 cm² thermal pad for rated power handling

Key Features

Feature	Design Value
TrenchFET® architecture	Enables 0.0053 Ω R_DS(on) at 4.5 V gate drive - eliminates need for higher-voltage gate drivers in 3.3 V/5 V control domains
100% R_g and UIS tested	Guarantees gate resistance ≤1.3 Ω and avalanche ruggedness (E_AS = 20 mJ) - supports reliable operation under transient overloads
Halogen-free construction	Complies with IEC 61249-2-21 - meets RoHS and green manufacturing requirements without performance trade-offs
Low V_GS(th) range	0.4–1.0 V threshold - ensures guaranteed turn-on with microcontroller GPIOs and low-voltage PWM ICs

Applications

Server VRM Synchronous Rectifier	USB-C PD 20 V Input Buck Converter
Use Scenario: High-current, high-frequency (500 kHz–1 MHz) output stage in server voltage regulator modules delivering up to 100 A per phase. IC Role / Device Role / Timing Role: Low-side synchronous rectifier replacing Schottky diodes to reduce conduction loss and improve thermal margin. Use Value: 0.0053 Ω R_DS(on) cuts conduction loss by >60% vs. 40 V Schottky, enabling 2–3 °C junction temperature reduction at 20 A.	Use Scenario: Secondary-side synchronous rectifier in USB-C Power Delivery adapters accepting 5–20 V input and regulating to 5/9/15/20 V outputs. IC Role / Device Role / Timing Role: N-channel switch controlled by dedicated SR controller (e.g., MP6908) to replace secondary-side diode. Use Value: 29.5 nC Q_g at 2.5 V enables fast switching with low-power SR controllers, reducing no-load consumption below 30 mW.
Industrial PLC Power Supply	Automotive ADAS Camera Module DC/DC
Use Scenario: 12 V input, 3.3 V/5 V output POL converter in programmable logic controller backplanes requiring -40 to +85 °C operation. IC Role / Device Role / Timing Role: High-efficiency power switch in synchronous buck stage with integrated controller (e.g., TPS54332). Use Value: R_thJF = 23 °C/W (junction-to-foot) allows direct thermal coupling to PCB ground plane, sustaining 16.1 A at T_A = 70 °C without airflow.	Use Scenario: Compact 12 V to 1.2 V/1.8 V buck converter powering image sensor and ISP in automotive camera modules (AEC-Q200 not claimed, but qualified for industrial temp range). IC Role / Device Role / Timing Role: Primary power FET in monolithic or controller-based buck stage operating at 1–2 MHz. Use Value: 0.0074 Ω R_DS(on) at V_GS = 1.8 V enables direct drive from low-voltage PMIC outputs, eliminating level-shifting circuitry.

Server VRM Synchronous Rectifier

USB-C PD 20 V Input Buck Converter

Use Scenario: High-current, high-frequency (500 kHz–1 MHz) output stage in server voltage regulator modules delivering up to 100 A per phase.

IC Role / Device Role / Timing Role: Low-side synchronous rectifier replacing Schottky diodes to reduce conduction loss and improve thermal margin.

Use Value: 0.0053 Ω R_DS(on) cuts conduction loss by >60% vs. 40 V Schottky, enabling 2–3 °C junction temperature reduction at 20 A.

Use Scenario: Secondary-side synchronous rectifier in USB-C Power Delivery adapters accepting 5–20 V input and regulating to 5/9/15/20 V outputs.

IC Role / Device Role / Timing Role: N-channel switch controlled by dedicated SR controller (e.g., MP6908) to replace secondary-side diode.

Use Value: 29.5 nC Q_g at 2.5 V enables fast switching with low-power SR controllers, reducing no-load consumption below 30 mW.

Industrial PLC Power Supply

Automotive ADAS Camera Module DC/DC

Use Scenario: 12 V input, 3.3 V/5 V output POL converter in programmable logic controller backplanes requiring -40 to +85 °C operation.

IC Role / Device Role / Timing Role: High-efficiency power switch in synchronous buck stage with integrated controller (e.g., TPS54332).

Use Value: R_thJF = 23 °C/W (junction-to-foot) allows direct thermal coupling to PCB ground plane, sustaining 16.1 A at T_A = 70 °C without airflow.

Use Scenario: Compact 12 V to 1.2 V/1.8 V buck converter powering image sensor and ISP in automotive camera modules (AEC-Q200 not claimed, but qualified for industrial temp range).

IC Role / Device Role / Timing Role: Primary power FET in monolithic or controller-based buck stage operating at 1–2 MHz.

Use Value: 0.0074 Ω R_DS(on) at V_GS = 1.8 V enables direct drive from low-voltage PMIC outputs, eliminating level-shifting circuitry.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
IRLML6344TRPBF	R_DS(on) = 0.028 Ω @ 4.5 V; smaller 1.6 mm × 1.6 mm SOT-23 package; lower I_D = 4.3 A	Targeted for space-constrained, lower-current (<5 A) loads like bias rails or LED drivers	Select when board area is critical and current demand is ≤5 A - not suitable for 20 A POL stages
DMN2004LK-7	R_DS(on) = 0.0055 Ω @ 4.5 V; same SO-8 footprint; slightly higher Q_g = 32 nC; halogen-free	Drop-in replacement in most SO-8 layouts; identical thermal pad layout and pinout	Choose for second-source assurance with matched R_DS(on), thermal performance, and Pb-free/halogen-free compliance

Compared with IRLML6344TRPBF, SI4866BDY-T1-E3 delivers 5× higher current capability and 80% lower R_DS(on), making it suitable for high-power POL; versus DMN2004LK-7, SI4866BDY-T1-E3 offers marginally lower gate charge and tighter V_GS(th) distribution for improved low-voltage turn-on consistency.

Availability

SI4866BDY-T1-E3 is available at Aetrix Electronics and suitable for server VRMs, USB-C PD adapters, industrial PLC power supplies, and automotive ADAS camera module DC/DC converters requiring stable component supply across extended production lifecycles.

Supply support for SI4866BDY-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 high-performance MOSFETs, diodes, and optoelectronics with emphasis on power efficiency and reliability.

The Si4866BDY product line delivers logic-level N-channel TrenchFET® MOSFETs optimized for high-current, low-voltage synchronous rectification and POL conversion in computing, communications, and industrial power systems.

FAQ

What is the maximum continuous drain current for SI4866BDY-T1-E3 at 70 °C case temperature?

The maximum continuous drain current for SI4866BDY-T1-E3 is 17.2 A at T_C = 70 °C, as specified in the Absolute Maximum Ratings table. This value reflects derating due to thermal limits and assumes proper PCB copper area for heat dissipation. The SI4866BDY-T1-E3 maintains its 0.0053 Ω R_DS(on) at this condition when driven with V_GS = 4.5 V.

Does SI4866BDY-T1-E3 support 1.8 V gate drive in production designs?

Yes, SI4866BDY-T1-E3 is fully characterized for 1.8 V gate drive: R_DS(on) = 0.0074 Ω at I_D = 8 A and V_GS = 1.8 V. Its V_GS(th) range of 0.4–1.0 V ensures reliable turn-on with 1.8 V logic outputs, and the SI4866BDY-T1-E3 datasheet provides full dynamic and thermal data at this voltage.

What is the thermal resistance from junction to ambient for SI4866BDY-T1-E3 on a standard FR4 board?

The typical junction-to-ambient thermal resistance (R_thJA) for SI4866BDY-T1-E3 is 40 °C/W when mounted on a 1" × 1" FR4 board, per the Thermal Resistance Ratings table. The maximum is 50 °C/W. This value applies to the SI4866BDY-T1-E3 in SO-8 package with standard soldering to a single-layer 1 oz copper pad.

Is SI4866BDY-T1-E3 suitable for synchronous rectifier applications with reverse recovery constraints?

Yes, SI4866BDY-T1-E3 includes a co-packaged body diode with t_rr = 50–80 ns and Q_rr = 35–55 nC, enabling effective synchronous rectification without external diode clamping. The SI4866BDY-T1-E3 body diode forward voltage is 0.62–1.1 V at I_S = 2.3 A, supporting low-loss freewheeling in buck converters.

What packaging and environmental compliance does SI4866BDY-T1-E3 meet?

SI4866BDY-T1-E3 is offered in lead (Pb)-free packaging per JEDEC J-STD-609, compliant with RoHS Directive 2011/65/EU. It is also halogen-free per IEC 61249-2-21, as confirmed in the Ordering Information and Features sections of the official Vishay datasheet for SI4866BDY-T1-E3.

SI4866BDY-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:: 21.5A (Tc)

Drive Voltage (Max Rds On, Min Rds On):: 1.8V, 4.5V

Rds On (Max) @ Id, Vgs:: 5.3mOhm @ 12A, 4.5V

Vgs(th) (Max) @ Id:: 1V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 80 nC @ 4.5 V

Vgs (Max):: ±8V

Input Capacitance (Ciss) (Max) @ Vds:: 5020 pF @ 6 V

FET Feature:: -

Power Dissipation (Max):: 4.45W (Tc)

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-SOIC

SI4866BDY-T1-E3 FAQ

1.How can I place an order for SI4866BDY-T1-E3 through Aetrix?

Please submit a Request for Quotation (RFQ) for SI4866BDY-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 SI4866BDY-T1-E3 reliable?

The price and inventory of SI4866BDY-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 SI4866BDY-T1-E3 is usually 5 days.

3.What payment methods are accepted for SI4866BDY-T1-E3?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SI4866BDY-T1-E3 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for SI4866BDY-T1-E3?

SI4866BDY-T1-E3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your SI4866BDY-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 SI4866BDY-T1-E3?

For technical support, including SI4866BDY-T1-E3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SI4866BDY-T1-E3 requirements.

6.How does Aetrix verify that SI4866BDY-T1-E3 is sourced from the original manufacturer or authorized distributors?

All SI4866BDY-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 SI4866BDY-T1-E3 meets industry standards.

7.What is the process for return or replacement of SI4866BDY-T1-E3?

All SI4866BDY-T1-E3 units undergo pre-shipment inspection (PSI). If there is an issue with SI4866BDY-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 SI4866BDY-T1-E3 part is unused and in its original packaging.

Return procedure for SI4866BDY-T1-E3:

1.Submit a request within 90 days.

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

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