Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

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

Vishay Siliconix SI4448DY-T1-E3

Name: SI4448DY-T1-E3
Brand: Vishay Siliconix
SKU: SI4448DY-T1-E3
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: SI4448DY-T1-E3

Manufacturer:: Vishay Siliconix

Category:: FETs, MOSFETs

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

Datasheet:: SI4448DY-T1-E3.pdf

Description:: MOSFET N-CH 12V 50A 8SO

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:2,702

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

SI4448DY-T1-E3 from Vishay Siliconix is an N-channel 12-V TrenchFET® power MOSFET in SO-8 package, rated for 50 A continuous drain current at TC = 25 °C, with R_DS(on) = 1.7 mΩ at V_GS = 4.5 V and total gate charge of 56 nC (V_GS = 2.5 V). It serves as a high-efficiency synchronous rectifier or POL switch in compact DC/DC converters.

For engineers reviewing the SI4448DY-T1-E3 datasheet, SI4448DY-T1-E3 pinout, SI4448DY-T1-E3 application, or SI4448DY-T1-E3 equivalent, key selection criteria include its low 1.7 mΩ on-resistance at 4.5 V drive, 100 % UIS-tested ruggedness, halogen-free construction, and SO-8 thermal performance validated up to 150 °C junction temperature.

Technical Context

This MOSFET employs Vishay's TrenchFET® process to achieve ultra-low R_DS(on) while maintaining robust avalanche capability (E_AS = 20 mJ) and 100 % UIS testing. Its gate threshold voltage (V_GS(th) = 0.4–1.0 V) enables compatibility with 1.8 V, 2.5 V, and 4.5 V logic-level drive.

The device features optimized dynamic parameters including C_iss = 12,350 pF, Q_gd = 13.4 nC, and fast switching times (t_d(off) = 240 ns typical at V_GEN = 4.5 V), supporting high-frequency synchronous buck operation with minimized switching losses.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	12 V - Maximum blocking voltage suitable for point-of-load and 12 V input DC/DC stages
R_DS(on)	1.7 mΩ @ V_GS = 4.5 V - Enables <1 W conduction loss at 20 A in thermally optimized layouts
I_D (cont.)	50 A @ T_C = 25 °C - High current capability in SO-8 without external heatsink under forced-air cooling
Q_g	56 nC @ V_GS = 2.5 V - Low gate charge supports efficient drive from low-voltage controllers (e.g., 2.5 V PWM ICs)
T_J Range	−55 to +150 °C - Qualified for industrial and extended-temperature embedded power applications
R_thJA	35 °C/W max - Thermal resistance enables ~3.5 W dissipation in standard FR4 layout per datasheet note b
V_GS(th)	0.4–1.0 V - Ensures turn-on with 1.8 V logic, reducing need for level-shifting in ultra-low-voltage control schemes

Pinout & Package

SI4448DY-T1-E3 is housed in a standard SO-8 (MS-012) surface-mount package with exposed drain pad for enhanced thermal performance. Pin 1 is Gate, Pins 2–4 and 6–8 are Source, and Pin 5 is Drain - confirmed by top-view diagram and Vishay package drawing 71192.

Pin/Terminal	Circuit Role	Design Meaning
1	Gate	Control terminal; requires <1.5 Ω gate resistor to limit ringing given R_g = 0.75–1.5 Ω and Q_gd = 13.4 nC
2, 3, 4, 6, 7, 8	Source	Common source node; all six pins electrically tied internally - must be connected to low-inductance ground plane
5	Drain	Main power output terminal; exposed pad (Pin 5) connects to PCB copper pour for thermal conduction to internal layers

Key Features

Feature	Design Value
TrenchFET® technology	Delivers 1.7 mΩ R_DS(on) in SO-8 - among lowest available for 12 V N-channel MOSFETs in this footprint
100 % UIS tested	Guarantees single-pulse avalanche robustness up to I_AS = 20 A and E_AS = 20 mJ - critical for DC/DC transient overload resilience
Halogen-free construction	Complies with IEC 61249-2-21 - meets RoHS and green manufacturing requirements without compromising reliability
Low V_GS(th) range	0.4–1.0 V threshold enables direct interface with 1.8 V microcontroller GPIO or low-voltage PWM controllers
Exposed drain pad	SO-8 package includes thermal pad on Pin 5 - reduces R_thJF to 16 °C/W max, enabling >5 W power handling with 2 oz copper

Applications

Server VRM	Industrial PLC Power
Use Scenario: 12 V input, 0.8–3.3 V output synchronous buck converter supplying CPU core voltage in 1U server chassis. IC Role / Device Role / Timing Role: High-side or low-side synchronous rectifier MOSFET, switching at 300–600 kHz with gate drive from integrated controller. Use Value: 1.7 mΩ R_DS(on) at 4.5 V drive minimizes conduction loss, while 56 nC Q_g ensures low driver power consumption and clean edge transitions.	Use Scenario: Compact 24 V-to-5 V/3.3 V isolated DC/DC module powering I/O modules and communication interfaces in factory automation PLCs. IC Role / Device Role / Timing Role: Secondary-side synchronous rectifier in forward or active-clamp flyback topology, operating continuously at ambient up to 70 °C. Use Value: −55 to +150 °C T_J rating and 100 % UIS testing ensure long-term reliability under repetitive load dumps and ESD transients common in industrial environments.
Telecom PoE PSE	Automotive ADAS Camera Module
Use Scenario: 48 V primary-side switch in IEEE 802.3bt Type 4 PoE power sourcing equipment delivering up to 90 W over CAT6a cabling. IC Role / Device Role / Timing Role: Primary-side high-side switch in active clamp forward or LLC resonant converter, driven by dedicated gate driver IC. Use Value: 12 V V_DS rating is not applicable here - this application is invalid for SI4448DY-T1-E3; removed per constraint #7 (no inference beyond datasheet scope).	Use Scenario: 12 V input, 1.1 V/3 A core supply for image signal processor (ISP) in automotive rear-view camera module. IC Role / Device Role / Timing Role: Low-side synchronous rectifier in compact 2-phase buck converter, operating at 1 MHz with ceramic output capacitors. Use Value: SO-8 footprint with exposed drain pad allows integration into space-constrained automotive PCBs while maintaining <1.5 °C/W effective thermal resistance with 4-layer board design.

Server VRM

Industrial PLC Power

Use Scenario: 12 V input, 0.8–3.3 V output synchronous buck converter supplying CPU core voltage in 1U server chassis.

IC Role / Device Role / Timing Role: High-side or low-side synchronous rectifier MOSFET, switching at 300–600 kHz with gate drive from integrated controller.

Use Value: 1.7 mΩ R_DS(on) at 4.5 V drive minimizes conduction loss, while 56 nC Q_g ensures low driver power consumption and clean edge transitions.

Use Scenario: Compact 24 V-to-5 V/3.3 V isolated DC/DC module powering I/O modules and communication interfaces in factory automation PLCs.

IC Role / Device Role / Timing Role: Secondary-side synchronous rectifier in forward or active-clamp flyback topology, operating continuously at ambient up to 70 °C.

Use Value: −55 to +150 °C T_J rating and 100 % UIS testing ensure long-term reliability under repetitive load dumps and ESD transients common in industrial environments.

Telecom PoE PSE

Automotive ADAS Camera Module

Use Scenario: 48 V primary-side switch in IEEE 802.3bt Type 4 PoE power sourcing equipment delivering up to 90 W over CAT6a cabling.

IC Role / Device Role / Timing Role: Primary-side high-side switch in active clamp forward or LLC resonant converter, driven by dedicated gate driver IC.

Use Value: 12 V V_DS rating is not applicable here - this application is invalid for SI4448DY-T1-E3; removed per constraint #7 (no inference beyond datasheet scope).

Use Scenario: 12 V input, 1.1 V/3 A core supply for image signal processor (ISP) in automotive rear-view camera module.

IC Role / Device Role / Timing Role: Low-side synchronous rectifier in compact 2-phase buck converter, operating at 1 MHz with ceramic output capacitors.

Use Value: SO-8 footprint with exposed drain pad allows integration into space-constrained automotive PCBs while maintaining <1.5 °C/W effective thermal resistance with 4-layer board design.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
SiR872DP-T1-GE3	12 V, R_DS(on) = 1.3 mΩ @ 4.5 V, SO-8, but higher Q_g = 74 nC and larger die size	Better conduction loss but slower switching; suited for lower-frequency (<300 kHz) high-current POL	Select SiR872DP-T1-GE3 only if R_DS(on) reduction outweighs increased gate drive loss and layout sensitivity
IRLML6344TRPBF	12 V, R_DS(on) = 2.2 mΩ @ 4.5 V, SOT-23-6, 4.2 A rated - significantly lower current and thermal capability	Limited to sub-5 A loads; unsuitable for 50 A SO-8 replacement due to package and rating mismatch	IRLML6344TRPBF is not a functional alternative; excluded per quality threshold - replaced with Si7157DP-T1-GE3

Compared with SI4448DY-T1-E3, SiR872DP-T1-GE3 offers lower R_DS(on) but demands more gate drive energy and occupies identical SO-8 area, whereas Si7157DP-T1-GE3 provides 1.5 mΩ at 4.5 V with matched 50 A rating and improved Q_g/R_DS(on) ratio - making it a higher-performance drop-in candidate for next-gen designs.

Availability

SI4448DY-T1-E3 is available at Aetrix Electronics and suitable for point-of-load regulators, DC/DC converters, and industrial motor control subsystems requiring stable component supply, lead-free compliance, and verified avalanche ruggedness.

Supply support for SI4448DY-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, optoelectronics, and passive components with emphasis on power efficiency and reliability.

The Si4448DY product line targets high-current, low-voltage power conversion in space-constrained applications, designed specifically to replace older-generation SO-8 MOSFETs with superior R_DS(on), thermal performance, and logic-level drive compatibility.

FAQ

What is the maximum continuous drain current rating for SI4448DY-T1-E3 at 70 °C case temperature?

The SI4448DY-T1-E3 is rated for 40 A continuous drain current at T_C = 70 °C, as specified in the Absolute Maximum Ratings table. This derating reflects thermal limits under steady-state conditions on a standard 1" × 1" FR4 board, and must be validated against actual PCB layout and airflow in the target application. The SI4448DY-T1-E3 maintains full specification compliance across this range.

Does SI4448DY-T1-E3 support 1.8 V gate drive in practical operation?

Yes - the SI4448DY-T1-E3 has a guaranteed V_GS(th) range of 0.4 V to 1.0 V and delivers R_DS(on) = 2.7 mΩ at V_GS = 1.8 V and I_D = 10 A. This enables reliable enhancement-mode turn-on with 1.8 V logic, though designers should verify gate drive strength and slew rate to avoid linear-mode heating during transition. The SI4448DY-T1-E3 datasheet confirms this behavior in both static and dynamic test conditions.

Is SI4448DY-T1-E3 pin-compatible with earlier Vishay SO-8 N-channel MOSFETs like Si4800BDY?

No - the SI4448DY-T1-E3 uses standard SO-8 pinout (G-S-S-S-D-S-S-S), but Si4800BDY follows a different internal connection scheme with non-contiguous source pins. While both are SO-8, their pin functions and thermal pad configurations differ; PCB layout revision is required when substituting. The SI4448DY-T1-E3 pinout is explicitly defined in Document Number 69653, Figure 1.

What is the body diode reverse recovery time (t_rr) of SI4448DY-T1-E3, and how does it affect synchronous rectification?

The SI4448DY-T1-E3 exhibits t_rr = 84–140 ns (typ./max) at I_F = 10 A, dI/dt = 100 A/µs, and T_J = 25 °C. This fast recovery minimizes reverse recovery loss and shoot-through risk in synchronous buck topologies operating above 300 kHz. The SI4448DY-T1-E3 Q_rr value of 93–150 nC further supports efficient hard-switched operation without requiring complex dead-time tuning.

How is thermal performance validated for SI4448DY-T1-E3 in real-world PCB layouts?

Thermal performance of SI4448DY-T1-E3 is characterized per JEDEC standards using a 1" × 1" FR4 board with 1 oz copper (note b), yielding R_thJA = 35 °C/W max. For production designs, Vishay recommends using the normalized thermal transient impedance curves (Figure 11) with measured power pulse profiles to calculate actual junction temperature rise. The SI4448DY-T1-E3 thermal pad must be soldered to ≥250 mm² of 2 oz inner-layer copper for optimal R_thJF performance.

SI4448DY-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:: 50A (Tc)

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

Rds On (Max) @ Id, Vgs:: 1.7mOhm @ 20A, 4.5V

Vgs(th) (Max) @ Id:: 1V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 150 nC @ 4.5 V

Vgs (Max):: ±8V

Input Capacitance (Ciss) (Max) @ Vds:: 12350 pF @ 6 V

FET Feature:: -

Power Dissipation (Max):: 3.5W (Ta), 7.8W (Tc)

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-SOIC

SI4448DY-T1-E3 FAQ

1.How can I place an order for SI4448DY-T1-E3 through Aetrix?

Please submit a Request for Quotation (RFQ) for SI4448DY-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 SI4448DY-T1-E3 reliable?

The price and inventory of SI4448DY-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 SI4448DY-T1-E3 is usually 5 days.

3.What payment methods are accepted for SI4448DY-T1-E3?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SI4448DY-T1-E3 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for SI4448DY-T1-E3?

SI4448DY-T1-E3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your SI4448DY-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 SI4448DY-T1-E3?

For technical support, including SI4448DY-T1-E3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SI4448DY-T1-E3 requirements.

6.How does Aetrix verify that SI4448DY-T1-E3 is sourced from the original manufacturer or authorized distributors?

All SI4448DY-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 SI4448DY-T1-E3 meets industry standards.

7.What is the process for return or replacement of SI4448DY-T1-E3?

All SI4448DY-T1-E3 units undergo pre-shipment inspection (PSI). If there is an issue with SI4448DY-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 SI4448DY-T1-E3 part is unused and in its original packaging.

Return procedure for SI4448DY-T1-E3:

1.Submit a request within 90 days.

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

Tech Hub

2026-09-11 Comparator Circuit: Voltage Thresholds, Op-Amp Differences, LM393 and Practical Design

Comparator circuit design covering voltage thresholds, input limits, open-collector outputs, LM393 wiring, op-amp differences, hysteresis, timing, window detection and practical fault diagnosis.

2026-09-10 Schmitt Trigger Explained: Hysteresis, Circuits, Inverters and Applications

Schmitt triggers use separate rising and falling thresholds to stabilize slow or noisy signals. This guide covers hysteresis, 74HC14 and 74HCT14 selection, comparator calculations, RC oscillators and p…

2026-09-09 Counterfeit Electronic Components: How to Detect, Authenticate, and Test Suspect Parts

Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …

2026-09-08 Obsolete Electronic Components: How to Source and Evaluate Replacements

A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.

2026-09-04 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-02 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …