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

Vishay Siliconix SI4128BDY-T1-GE3

Name: SI4128BDY-T1-GE3
Brand: Vishay Siliconix
SKU: SI4128BDY-T1-GE3
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: SI4128BDY-T1-GE3

Manufacturer:: Vishay Siliconix

Category:: FETs, MOSFETs

Package:: -

Datasheet:: SI4128BDY-T1-GE3.pdf

Description:: MOSFET N-CH 30V

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Product details

Overview

SI4128BDY-T1-GE3 from Vishay Siliconix is an N-channel 30 V (D-S) TrenchFET® Power MOSFET in SO-8 package, with R_DS(on) = 0.021 Ω at V_GS = 10 V, 12 A continuous drain current, and 3.7 nC total gate charge. It serves as a high-efficiency synchronous rectifier or load switch in notebook system power rails.

For engineers reviewing the SI4128BDY-T1-GE3 datasheet, SI4128BDY-T1-GE3 pinout, SI4128BDY-T1-GE3 application, or SI4128BDY-T1-GE3 equivalent, key selection criteria include its 30 V V_DS, low R_DS(on) at 4.5 V drive, 100 % R_g and UIS tested reliability, and halogen-free RoHS-compliant construction.

Technical Context

This MOSFET uses trench-gate silicon technology optimized for low conduction loss and fast switching in DC/DC converter high-side or low-side configurations. Its 0.033 Ω R_DS(on) at 4.5 V enables operation with 5 V logic-level gate drive, while 56 pF Crss and 7.5–12 nC Q_g support efficient PWM control up to several hundred kHz.

The device features a built-in body diode with 0.85–1.2 V V_SD at 6.7 A and 15–30 ns trr, suitable for freewheeling in buck converters. Thermal resistance R_thJA is 42–53 °C/W on FR4, and R_thJF is 19–25 °C/W to the drain foot-critical for thermal design in compact notebook power stages.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	30 V - Maximum blocking voltage compatible with 24 V input rails and transient margin in notebook adapters.
R_DS(on) @ 10 V	0.021 Ω - Enables ≤2.1 W conduction loss at 10 A, reducing thermal load in space-constrained PCBs.
R_DS(on) @ 4.5 V	0.033 Ω - Supports direct drive from 5 V microcontrollers or PWM controllers without level-shifting.
Q_g (10 V)	7.5–12 nC - Determines gate driver power requirement and switching loss in 300–500 kHz DC/DC topologies.
I_D (T_C = 25 °C)	12 A - Continuous current rating at case temperature, defining safe operating area for surface-mount thermal management.
t_rr	15–30 ns - Body diode recovery speed limits reverse recovery loss and EMI in synchronous rectification.
R_thJA	42–53 °C/W - Junction-to-ambient thermal resistance on 1" × 1" FR4 board, used to calculate max ambient temperature rise.

Pinout & Package

SO-8 (MS-012) package with exposed drain pad for thermal enhancement; 8-pin surface-mount outline per JEDEC MS-012, 5.0 mm × 4.0 mm footprint, 1.75 mm max height.

Pin/Terminal	Circuit Role	Design Meaning
1 (G)	Gate	Control terminal; requires ≥10 V for full enhancement, compatible with 5 V logic via R_DS(on) spec at 4.5 V.
2 (S)	Source	Reference node for gate drive; tied to power ground in low-side switch configuration.
3 (D)	Drain	Main current path output; internally connected to exposed pad for thermal conduction to PCB copper.
4 (D)	Drain	Parallel drain connection; electrically identical to Pin 3, increases current handling and thermal dissipation.
5 (D)	Drain	Parallel drain connection; shares same internal node as Pins 3 and 4 for reduced R_DS(on) and thermal impedance.
6 (D)	Drain	Parallel drain connection; completes quad-drain layout for optimal current sharing and heat spreading.
7 (S)	Source	Secondary source terminal; bonded to same internal source region as Pin 2, improves current distribution.
8 (S)	Source	Secondary source terminal; reduces source inductance in high-frequency switching applications.

Key Features

Feature	Design Value
TrenchFET® architecture	Enables lower R_DS(on) per die area than planar MOSFETs, supporting compact 8-pin SOIC packaging with 12 A rating.
100 % R_g and UIS tested	Each unit undergoes gate resistance screening and unclamped inductive switching stress test, ensuring robustness in real-world load dump events.
Halogen-free & RoHS compliant	Meets IEC 61249-2-21 and Directive 2002/95/EC, enabling use in environmentally regulated consumer electronics like notebooks.
Exposed drain pad	Thermal path from junction to PCB via Pin 3–6 and underside metal, lowering R_thJF to 19–25 °C/W for improved power density.

Applications

Notebook CPU Core VRM	USB-C PD Secondary Side Switch
Use Scenario: High-current, high-efficiency step-down conversion delivering 1–2 V at up to 25 A to modern laptop CPUs. IC Role / Device Role / Timing Role: Low-side synchronous rectifier in multiphase buck converter, switching at 300–600 kHz with precise dead-time control. Use Value: 0.021 Ω R_DS(on) minimizes conduction loss at high load, while 3.7 nC Q_g reduces gate drive power and EMI generation.	Use Scenario: Load switch controlling 5–20 V power delivery to USB-C peripherals in portable docking stations. IC Role / Device Role / Timing Role: Single-pole single-throw (SPST) power switch with controlled turn-on slew rate to prevent inrush current. Use Value: 30 V V_DS accommodates 20 V PD 3.0 inputs; 0.033 Ω R_DS(on) at 4.5 V allows direct MCU GPIO control without external drivers.
Low-Current DC/DC Converter	Embedded System Power Sequencing
Use Scenario: Point-of-load regulation for FPGA I/O banks or sensor subsystems requiring 1.2–3.3 V at <10 A. IC Role / Device Role / Timing Role: High-side switch in buck or buck-boost topology, driven by integrated controller with bootstrap gate drive. Use Value: Fast 10–15 ns fall time and 56 pF Crss enable clean switching edges and minimal shoot-through risk in high-frequency designs.	Use Scenario: Controlled power-up/down sequencing of multiple voltage rails in industrial IoT gateways or edge AI modules. IC Role / Device Role / Timing Role: Standalone power enable switch activated by system supervisor IC or microcontroller GPIO. Use Value: ±25 V V_GS rating tolerates transient coupling during hot-swap events; 100 % UIS tested ensures survival under rail collapse conditions.

Notebook CPU Core VRM

USB-C PD Secondary Side Switch

Use Scenario: High-current, high-efficiency step-down conversion delivering 1–2 V at up to 25 A to modern laptop CPUs.

IC Role / Device Role / Timing Role: Low-side synchronous rectifier in multiphase buck converter, switching at 300–600 kHz with precise dead-time control.

Use Value: 0.021 Ω R_DS(on) minimizes conduction loss at high load, while 3.7 nC Q_g reduces gate drive power and EMI generation.

Use Scenario: Load switch controlling 5–20 V power delivery to USB-C peripherals in portable docking stations.

IC Role / Device Role / Timing Role: Single-pole single-throw (SPST) power switch with controlled turn-on slew rate to prevent inrush current.

Use Value: 30 V V_DS accommodates 20 V PD 3.0 inputs; 0.033 Ω R_DS(on) at 4.5 V allows direct MCU GPIO control without external drivers.

Low-Current DC/DC Converter

Embedded System Power Sequencing

Use Scenario: Point-of-load regulation for FPGA I/O banks or sensor subsystems requiring 1.2–3.3 V at <10 A.

IC Role / Device Role / Timing Role: High-side switch in buck or buck-boost topology, driven by integrated controller with bootstrap gate drive.

Use Value: Fast 10–15 ns fall time and 56 pF Crss enable clean switching edges and minimal shoot-through risk in high-frequency designs.

Use Scenario: Controlled power-up/down sequencing of multiple voltage rails in industrial IoT gateways or edge AI modules.

IC Role / Device Role / Timing Role: Standalone power enable switch activated by system supervisor IC or microcontroller GPIO.

Use Value: ±25 V V_GS rating tolerates transient coupling during hot-swap events; 100 % UIS tested ensures survival under rail collapse conditions.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
Si7157DP-T1-GE3	30 V, 0.022 Ω @ 10 V, SO-8, but higher Q_g (14.5 nC) and no 4.5 V R_DS(on) spec.	Less suitable for 5 V gate drive; better for fixed 10 V controller interfaces.	Choose when gate drive voltage is stable ≥10 V and lower switching loss is prioritized over gate drive simplicity.
IRF7470PBF	30 V, 0.024 Ω @ 10 V, SO-8, but only 8 A I_D rating and no halogen-free certification.	Lower current capacity and non-RoHS-compliant; unsuitable for new notebook designs.	Consider only for legacy repair or cost-sensitive industrial applications where environmental compliance is not required.

Compared with Si7157DP-T1-GE3 and IRF7470PBF, the SI4128BDY-T1-GE3 offers superior 4.5 V drive capability and halogen-free compliance-key for next-generation portable electronics-while maintaining competitive R_DS(on) and thermal performance in the SO-8 footprint.

Availability

SI4128BDY-T1-GE3 is available at Aetrix Electronics and suitable for notebook system power, low-current DC/DC converters, and embedded power sequencing requiring stable component supply across multi-year production cycles.

Supply support for SI4128BDY-T1-GE3 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 semiconductor manufacturer specializing in discrete power MOSFETs, diodes, and optoelectronics, with emphasis on high-reliability, high-efficiency components for computing and industrial markets.

The SI4128BDY-T1-GE3 belongs to Vishay's TrenchFET® Gen III family, engineered specifically for high-current, low-voltage DC/DC conversion in space-constrained portable electronics where thermal efficiency and logic-level drive are critical.

FAQ

What is the maximum continuous drain current for SI4128BDY-T1-GE3 at 70 °C case temperature?

The SI4128BDY-T1-GE3 supports 9.7 A continuous drain current at T_C = 70 °C, as specified in the Absolute Maximum Ratings table. This derating reflects thermal limitations of the SO-8 package under sustained power dissipation, and must be verified against actual PCB layout and airflow conditions in the final design.

Does SI4128BDY-T1-GE3 support 5 V gate drive in practical applications?

Yes, the SI4128BDY-T1-GE3 is characterized with R_DS(on) = 0.033 Ω at V_GS = 4.5 V and I_D = 2 A, confirming reliable enhancement with standard 5 V logic outputs. Its gate threshold voltage range (1.4–2.8 V) ensures turn-on well within typical 5 V CMOS drive margins.

What is the thermal resistance from junction to ambient for SI4128BDY-T1-GE3 on a standard PCB?

The SI4128BDY-T1-GE3 has a typical R_thJA of 42 °C/W and maximum of 53 °C/W when mounted on a 1" × 1" FR4 board, per the Thermal Resistance Ratings table. This value assumes standard solder mask-defined copper pour and no additional heatsinking.

Is SI4128BDY-T1-GE3 suitable for synchronous rectification in buck converters?

Yes, the SI4128BDY-T1-GE3 is explicitly recommended for synchronous rectification, with a body diode V_SD of 0.85–1.2 V at 6.7 A and reverse recovery time trr of 15–30 ns. Its low Q_rr (8–16 nC) and fast switching reduce conduction and recovery losses versus Schottky alternatives.

What does the "-GE3" suffix indicate in SI4128BDY-T1-GE3?

The "-GE3" suffix denotes Vishay's green, lead (Pb)-free, and halogen-free packaging per IEC 61249-2-21 and RoHS Directive 2002/95/EC. It confirms compliance with environmental regulations for consumer electronics, including notebooks and portable devices.

SI4128BDY-T1-GE3 Specifications

Product attributes: Attribute value

Manufacturer:: Vishay Siliconix

Series:: TrenchFET®

Package/Case:: -

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

FET Type:: -

Technology:: -

Drain to Source Voltage (Vdss):: -

Current - Continuous Drain (Id) @ 25°C:: 8.3A (Ta), 12A (Tc)

Drive Voltage (Max Rds On, Min Rds On):: 4.5V, 10V

Rds On (Max) @ Id, Vgs:: -

Vgs(th) (Max) @ Id:: -

Gate Charge (Qg) (Max) @ Vgs:: -

Vgs (Max):: ±25V

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

FET Feature:: -

Power Dissipation (Max):: -

Operating Temperature:: -

Grade:: -

Qualification:: -

Mounting Type:: -

Supplier Device Package:: -

SI4128BDY-T1-GE3 FAQ

1.How can I place an order for SI4128BDY-T1-GE3 through Aetrix?

Please submit a Request for Quotation (RFQ) for SI4128BDY-T1-GE3 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 SI4128BDY-T1-GE3 reliable?

The price and inventory of SI4128BDY-T1-GE3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SI4128BDY-T1-GE3 is usually 5 days.

3.What payment methods are accepted for SI4128BDY-T1-GE3?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SI4128BDY-T1-GE3 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for SI4128BDY-T1-GE3?

SI4128BDY-T1-GE3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your SI4128BDY-T1-GE3 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 SI4128BDY-T1-GE3?

For technical support, including SI4128BDY-T1-GE3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SI4128BDY-T1-GE3 requirements.

6.How does Aetrix verify that SI4128BDY-T1-GE3 is sourced from the original manufacturer or authorized distributors?

All SI4128BDY-T1-GE3 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 SI4128BDY-T1-GE3 meets industry standards.

7.What is the process for return or replacement of SI4128BDY-T1-GE3?

All SI4128BDY-T1-GE3 units undergo pre-shipment inspection (PSI). If there is an issue with SI4128BDY-T1-GE3, 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 SI4128BDY-T1-GE3 part is unused and in its original packaging.

Return procedure for SI4128BDY-T1-GE3:

1.Submit a request within 90 days.

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

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