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

STMicroelectronics STS4DNFS30

Name: STS4DNFS30
Brand: STMicroelectronics
SKU: STS4DNFS30
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: STS4DNFS30

Manufacturer:: STMicroelectronics

Category:: FETs, MOSFETs

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

Datasheet:: STS4DNFS30.pdf

Description:: MOSFET N-CH 30V 4.5A 8SO

Quantity:: RFQ Add To RFQ list

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Inventory:1,500

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Product details

Overview

STS4DNFS30 from STMicroelectronics is an integrated N-channel 30V Power MOSFET with co-packaged Schottky rectifier in SO-8 package, delivering R_DS(on) = 0.044Ω @ V_GS = 10V, 4.5A continuous drain current, and 30V reverse blocking for the Schottky section. It serves as a synchronous rectifier or high-side/low-side switch in compact DC-DC converters for portable printers and battery-powered equipment.

For engineers reviewing the STS4DNFS30 datasheet, STS4DNFS30 pinout, STS4DNFS30 application, or STS4DNFS30 equivalent, this device requires attention to its dual-function layout (MOSFET + Schottky), gate drive compatibility at 5V logic levels, thermal derating above 100°C, and safe operating area limits under pulsed inductive loads.

Technical Context

The STS4DNFS30 integrates a STripFET™ II n-channel MOSFET and a low-drop Schottky diode on a single die substrate within an SO-8 thermally enhanced leadframe. Its MOSFET channel exhibits 1V gate threshold voltage and 5S transconductance, while the Schottky section provides 0.325V forward voltage at 2A and 0.43V at 4A (T_j = 25°C).

Switching performance is characterized by 9ns turn-on delay, 17ns rise time, 15ns turn-off delay, and 6ns fall time under 4.7Ω gate resistance; reverse recovery is minimized via Schottky's inherent zero-charge behavior (t_rr = 22ns, Q_rr = 14.3nC only for source-drain body diode conduction).

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	30V - Maximum drain-source blocking voltage; defines upper limit for buck converter input or half-bridge rail voltage.
R_DS(on)	0.044Ω @ V_GS = 10V - Conduction loss of 0.89W at 4.5A; enables high-efficiency operation below 10W output power.
I_D(cont)	4.5A @ T_C = 25°C - Continuous current rating limited by 2W total dissipation; derates to 3.2A at 100°C case temperature.
V_F(Schottky)	0.43V @ I_F = 4A, T_j = 25°C - Low forward drop reduces rectifier losses in synchronous or freewheeling paths.
Q_g	4.7nC @ V_DD = 15V, I_D = 4.5A - Gate charge determines required driver peak current and switching loss trade-off.
t_r/t_f	17ns/6ns - Fast edge rates support >1MHz switching in space-constrained DC-DC designs.
R_thj-amb	62.5°C/W on FR-4 - Thermal resistance dictates minimum copper pour area needed for 1.5W steady-state dissipation.

Pinout & Package

STS4DNFS30 uses the standard SO-8 surface-mount package (JEDEC MS-012AC) with exposed thermal pad connected internally to the MOSFET drain and Schottky cathode. Pin 1 is gate, pins 2–4 are source (MOSFET and Schottky anode tied together), pins 5–8 are drain (common for both devices). The package supports hand-soldering and reflow per JEDEC J-STD-020.

Pin/Terminal	Circuit Role	Design Meaning
1	Gate	Controls MOSFET conduction; requires ≥1V threshold and ≤±20V absolute max gate-source voltage.
2, 3, 4	Source / Schottky Anode	Common node for MOSFET source and Schottky anode; must be routed as low-inductance power return path.
5, 6, 7, 8	Drain / Schottky Cathode	Common drain terminal and Schottky cathode; carries full load current and absorbs inductive flyback energy.

Key Features

Feature	Design Value
Integrated Schottky + MOSFET	Single-package solution eliminates layout mismatch between discrete switch and rectifier, reducing parasitic inductance in high-frequency converters.
Low R_DS(on)	0.044Ω enables <1W conduction loss at 4.5A, supporting thermally constrained portable applications without forced cooling.
Logic-level gate drive	1V V_GS(th) and full enhancement at 5V allows direct interface with 3.3V/5V microcontrollers and PWM controllers without level-shifting.
ECOPACK® RoHS-compliant	Lead-free second-level interconnect meets JEDEC JESD97 marking requirements and environmental compliance for global OEM shipments.
SO-8 thermal pad	Exposed drain pad improves heat transfer to PCB copper; achieves 62.5°C/W junction-to-ambient on standard FR-4 board.

Applications

Portable Printer Power Supply

USB-C PD Buck Converter

Use Scenario: Step-down conversion from 12V battery to 5V/3.3V logic rails in compact inkjet printer mainboard.

IC Role / Device Role / Timing Role: Synchronous rectifier in continuous conduction mode (CCM) buck stage, replacing external Schottky diode to improve efficiency.

Use Value: 0.43V Schottky forward drop and 0.044Ω R_DS(on) reduce total conduction loss by ~35% versus discrete 1N5822 + MOSFET solution at 3A load.

Use Scenario: Secondary-side synchronous rectification in 20W USB-C PD adapter with 5–20V input range.

IC Role / Device Role / Timing Role: Low-side switch with integrated freewheeling diode in active-clamp flyback or buck-derived topology.

Use Value: Co-packaged structure ensures matched thermal behavior between MOSFET and Schottky, eliminating timing skew in critical dead-time management.

Medical Handheld Monitor DC-DC

Industrial Sensor Node Power

Use Scenario: Isolated 3.3V supply generation from 9V Li-ion battery for ECG front-end analog circuitry.

IC Role / Device Role / Timing Role: High-side switch in non-isolated buck-boost regulator with integrated catch diode for bidirectional current handling.

Use Value: 30V V_RRM and 4.5A I_F(AV) allow safe operation across full battery discharge curve (9V → 6.5V) without derating.

Use Scenario: Ultra-low-quiescent step-down regulator powering LoRaWAN sensor node MCU and RF transceiver.

IC Role / Device Role / Timing Role: Primary switching element in pulse-skipping buck converter optimized for intermittent 10mA average load.

Use Value: 1V gate threshold enables reliable turn-on during brown-out conditions down to 2.7V supply, maintaining system uptime.

Equivalent & Alternatives

The following parts are listed as comparable options for similar integrated MOSFET + Schottky applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
STL135N3LLH6	30V, 135A, 1.35mΩ, no integrated Schottky; H2PAK-2 package	Designed for high-current motor drives, not DC-DC rectification	Select only when discrete Schottky placement and thermal separation are preferred over integration.
FDMS86182	30V, 15A, 0.0055Ω, integrated Schottky, PowerTrench® SyncFET™, 5×6mm PQFN	Higher current, lower R_DS(on), smaller footprint, but requires different PCB layout and gate drive tuning	Choose for new designs targeting >10W output where SO-8 thermal limits are insufficient.

Compared with STL135N3LLH6 and FDMS86182, STS4DNFS30 offers optimal balance of integration density, 4.5A capability, and SO-8 manufacturability for sub-10W portable DC-DC converters-where FDMS86182 exceeds thermal needs and STL135N3LLH6 lacks rectifier integration.

Availability

STS4DNFS30 is available at Aetrix Electronics and suitable for portable printer power supplies, USB-C PD secondary-side regulation, medical handheld monitor DC-DC stages, and industrial sensor node power conversion requiring stable component supply and legacy design continuity.

Supply support for STS4DNFS30 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing silicon solutions for automotive, industrial, and consumer markets since 1987.

The STS4DNFS30 belongs to ST's STripFET™ Power MOSFET family, engineered specifically for high-efficiency, space-constrained DC-DC conversion in portable and battery-operated systems where integration, thermal performance, and logic-level drive are critical.

FAQ

Is STS4DNFS30 still in active production?

No-STS4DNFS30 is marked as obsolete in ST's official documentation (Rev 1, July 2006). However, Aetrix Electronics maintains legacy inventory with full traceability and supports ongoing production for qualified industrial and medical programs through controlled lifetime buy programs and cross-reference engineering guidance.

Can STS4DNFS30 be used in synchronous rectification mode?

Yes-its integrated Schottky diode and low R_DS(on) enable synchronous rectification in buck, boost, and flyback topologies. Gate timing must ensure MOSFET turn-on before Schottky conduction ends to avoid shoot-through; typical dead-time control is 50–100ns at 500kHz switching.

What is the maximum safe operating frequency for STS4DNFS30?

Based on measured t_r/t_f (17ns/6ns) and Q_g (4.7nC), STS4DNFS30 supports reliable operation up to 2MHz in well-designed layouts with low-inductance gate loops and adequate gate drive strength (>1A peak). Efficiency drops above 1.5MHz due to increased switching losses.

Does the SO-8 thermal pad require solder paste stencil aperture adjustment?

Yes-the exposed drain pad (pins 5–8) must be printed with a 70–80% solder paste coverage stencil aperture to ensure void-free thermal attachment. ST recommends a 3×3 array of 0.3mm diameter solder vias under the pad connected to inner-layer ground planes for optimal thermal performance on FR-4 boards.

STS4DNFS30 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: STripFET™

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):: 30 V

Current - Continuous Drain (Id) @ 25°C:: 4.5A (Tc)

Drive Voltage (Max Rds On, Min Rds On):: 5V, 10V

Rds On (Max) @ Id, Vgs:: 55mOhm @ 2A, 10V

Vgs(th) (Max) @ Id:: 1V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 4.7 nC @ 5 V

Vgs (Max):: ±20V

Input Capacitance (Ciss) (Max) @ Vds:: 330 pF @ 25 V

FET Feature:: Schottky Diode (Isolated)

Power Dissipation (Max):: 2W (Tc)

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-SOIC

STS4DNFS30 FAQ

1.How can I place an order for STS4DNFS30 through Aetrix?

Please submit a Request for Quotation (RFQ) for STS4DNFS30 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 STS4DNFS30 reliable?

The price and inventory of STS4DNFS30 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STS4DNFS30 is usually 5 days.

3.What payment methods are accepted for STS4DNFS30?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STS4DNFS30 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for STS4DNFS30?

STS4DNFS30 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your STS4DNFS30 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 STS4DNFS30?

For technical support, including STS4DNFS30 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STS4DNFS30 requirements.

6.How does Aetrix verify that STS4DNFS30 is sourced from the original manufacturer or authorized distributors?

All STS4DNFS30 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 STS4DNFS30 meets industry standards.

7.What is the process for return or replacement of STS4DNFS30?

All STS4DNFS30 units undergo pre-shipment inspection (PSI). If there is an issue with STS4DNFS30, 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 STS4DNFS30 part is unused and in its original packaging.

Return procedure for STS4DNFS30:

1.Submit a request within 90 days.

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

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