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Home > Products > Discrete Semiconductor Products > Diodes > Rectifiers > Single Diodes

STMicroelectronics STPS3L40S

Name: STPS3L40S
Brand: STMicroelectronics
SKU: STPS3L40S
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: STPS3L40S

Manufacturer:: STMicroelectronics

Category:: Single Diodes

Package:: DO-214AB, SMC

Datasheet:: STPS3L40S.pdf

Description:: DIODE SCHOTTKY 40V 3A SMC

Quantity:: RFQ Add To RFQ list

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Inventory:7,474

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Product details

Overview

STPS3L40S from STMicroelectronics is a 40 V, 3 A low-drop Schottky rectifier in SMC package, designed for high-frequency DC/DC converters and switch-mode power supplies. It features a typical forward voltage drop of 0.40 V at 3 A and 125 °C, negligible switching losses, avalanche rating, and thermal resistance of 18 °C/W (junction-to-lead), enabling efficient operation in TV and telecom power supplies.

For engineers reviewing the STPS3L40S datasheet, STPS3L40S pinout, STPS3L40S application, or STPS3L40S equivalent, key selection criteria include its 40 V reverse voltage rating, 3 A average forward current capability at 115 °C ambient, low VF performance across temperature, avalanche energy handling (95 W peak), and SMC surface-mount compatibility for high-power-density board layouts.

Technical Context

This Schottky rectifier operates as a unidirectional power conversion device in freewheeling and output rectification stages of isolated and non-isolated DC/DC topologies. Its metal–semiconductor junction enables zero minority-carrier storage, eliminating reverse recovery time and associated switching losses.

Thermal design relies on direct lead conduction: R_th(j-l) = 18 °C/W for SMC package, with derated I_F(AV) up to 3 A at T_L = 115 °C. Avalanche capability supports transient overvoltage resilience without external clamping in compact power designs.

Key Specifications

Parameter	Value and Actual Design Meaning
V_RRM	40 V - Maximum repetitive reverse blocking voltage; defines safe operating range in secondary-side rectification of ≤36 V nominal output supplies.
I_F(AV)	3 A at T_L = 115 °C - Continuous DC output current capability under real-world PCB thermal conditions using SMC leads as heat paths.
V_F(typ)	0.40 V at I_F = 3 A, T_j = 125 °C - Enables <1.2 W conduction loss per diode in 12 V/3 A outputs, critical for >90% efficiency targets.
I_FSM	75 A (10 ms sine) - Withstands inrush and short-circuit surge currents without failure, reducing need for upstream fusing.
R_th(j-l)	18 °C/W - Junction-to-lead thermal resistance confirms effective self-heating management via copper land and solder joint conduction in SMC footprint.
P_ARM	95 W (10 µs pulse, T_j = 125 °C) - Specifies single-pulse avalanche energy handling, supporting robustness against line transients in offline SMPS front-ends.

Pinout & Package

Package: SMC (Surface Mount Case), JEDEC DO-214AB compliant, lead-free, UL94 V0 epoxy body, optimized for high-current thermal dissipation via wide copper pads and dual leads.

Pin/Terminal	Circuit Role	Design Meaning
Anode (A)	Current entry point during forward conduction	Connected to switching node (e.g., transformer secondary center-tap or buck converter switch node); must be routed with low-inductance copper pour.
Cathode (K)	Current exit point during forward conduction	Connected to output capacitor ground return; serves as primary thermal path to PCB copper; requires ≥200 mm² 2-oz copper pad per lead.

Key Features

Feature	Design Value
Negligible switching losses	No reverse recovery charge (Q_rr ≈ 0), eliminating turn-off loss and EMI from diode snap-off in 100–500 kHz DC/DC converters.
Low forward voltage drop	V_F ≤ 0.44 V at 3 A/125 °C ensures <1.3 W conduction loss, directly improving thermal margin in sealed TV power enclosures.
Avalanche rated	95 W peak avalanche power (10 µs) allows operation without snubbers in flyback or forward converters subject to leakage inductance spikes.
Low thermal resistance	R_th(j-l) = 18 °C/W enables 3 A continuous current with only 54 °C junction rise above lead temperature-critical for fanless set-top box designs.

Applications

Telecom Power Supply

TV Power Supply

Use Scenario: Secondary-side synchronous rectification in 48 V input, 12 V/3 A isolated DC/DC modules for base station remote radio units.

IC Role / Device Role / Timing Role: Output rectifier replacing MOSFET + driver; provides fixed-voltage drop with no gate timing constraints.

Use Value: Eliminates gate drive complexity and shoot-through risk while maintaining >92% efficiency at full load with <0.5 °C/W effective thermal resistance to ambient.

Use Scenario: Main 24 V output rectification in slim LED TV power supplies with forced-air or passive heatsink cooling.

IC Role / Device Role / Timing Role: Freewheeling diode in active-clamp forward converter; handles 3 A DC + 2 A ripple at 200 kHz switching frequency.

Use Value: Reduces system BOM count by removing snubber RC network due to rated avalanche energy absorption during clamp reset.

Set-Top Box Power Supply

Battery Charger

Use Scenario: 5 V/3 A standby rail rectification in multi-output flyback PSUs for cable/satellite receivers with tight enclosure volume.

IC Role / Device Role / Timing Role: Low-VF output rectifier minimizing conduction loss in thermally constrained plastic housings.

Use Value: Enables 5 V rail efficiency >88% at 100 mA–3 A load range without active cooling, meeting ENERGY STAR Tier 2 standby requirements.

Use Scenario: Output rectification in 19.5 V/3 A laptop adapter DC/DC stage with universal AC input and PFC front-end.

IC Role / Device Role / Timing Role: High-reliability secondary-side diode handling repeated 75 A surge events during hot-plug connector mating.

Use Value: Survives >10,000 mating cycles without degradation due to avalanche-rated construction and robust SMC mechanical integrity.

Equivalent & Alternatives

The following parts are listed as comparable options for similar Schottky rectifier applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
Vishay VS-3EYH04-M3/54	Same 40 V V_RRM, 3 A I_F(AV), but VF = 0.52 V (typ) at 3 A/125 °C; R_th(j-l) = 20 °C/W in SMA package.	Higher conduction loss (+0.36 W at 3 A) and lower thermal conductivity limit usable current to 2.6 A at same board layout.	Select when legacy SMA footprint compatibility is required and 0.12 V higher VF is acceptable for cost-sensitive designs.
ON Semiconductor SB340-TB	40 V V_RRM, 3 A I_F(AV), VF = 0.55 V (typ) at 3 A/25 °C; no avalanche rating; SMB package with R_th(j-l) = 22 °C/W.	Lacks avalanche ruggedness and exhibits higher VF drift with temperature, requiring derating in transient-prone industrial chargers.	Prefer only in benign, low-surge consumer charger applications where cost is primary and thermal margin exceeds 25 °C.

Compared with VS-3EYH04-M3/54 and SB340-TB, STPS3L40S delivers superior thermal performance (18 °C/W), lowest VF across temperature, and guaranteed avalanche energy handling-making it the optimal choice for space-constrained, high-reliability telecom and broadcast power systems.

Availability

STPS3L40S is available at Aetrix Electronics and suitable for telecom power supply, TV power supply, and battery charger designs requiring stable component supply, long-term lifecycle support, and RoHS-compliant SMC packaging.

Supply support for STPS3L40S 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 analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

The STPS series targets high-efficiency, high-reliability power conversion applications-specifically engineered for Schottky rectification in compact, thermally demanding switch-mode power supplies where low VF and avalanche tolerance are mandatory.

FAQ

What is the maximum junction temperature and how is it enforced?

The absolute maximum junction temperature is +150 °C, validated under conditions where (dP_tot/dT_j) < (1/R_th(j-a)) to prevent thermal runaway. This requires minimum PCB copper area per lead (≥200 mm²) and limits ambient temperature to ≤115 °C when operating at full 3 A load in SMC package.

Does STPS3L40S require a heatsink for 3 A continuous operation?

No external heatsink is required. At 3 A DC and T_L = 115 °C, the SMC package achieves thermal equilibrium using PCB copper as the primary heatsink. Designers must implement ≥200 mm² of 2-oz copper connected to each lead, per AN5088 recommendations, to maintain T_j ≤ 150 °C.

How does the avalanche rating improve reliability in flyback converters?

In flyback topologies, leakage inductance causes voltage spikes across the output rectifier during MOSFET turn-off. The STPS3L40S's 95 W peak avalanche power (10 µs) absorbs these spikes without breakdown, eliminating the need for external RCD snubbers and improving long-term reliability in unregulated or variable-load conditions.

Can STPS3L40S replace older STPS3L40 variants in existing designs?

Yes-STPS3L40S shares identical electrical specifications, thermal behavior, and SMC mechanical footprint with STPS3L40 (no suffix). The "S" suffix denotes tape-and-reel packaging (10,000 pcs/reel) and ECOPACK2 compliance; no circuit or layout changes are needed for drop-in replacement in production.

STPS3L40S Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: DO-214AB, SMC

Packaging:: Tape & Reel (TR)

Product Status:: Active

Technology:: Schottky

Voltage - DC Reverse (Vr) (Max):: 40 V

Current - Average Rectified (Io):: 3A

Voltage - Forward (Vf) (Max) @ If:: 500 mV @ 3 A

Speed:: Fast Recovery =< 500ns, > 200mA (Io)

Reverse Recovery Time (trr):: -

Current - Reverse Leakage @ Vr:: 100 µA @ 40 V

Capacitance @ Vr, F:: -

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SMC

Operating Temperature - Junction:: 150°C (Max)

STPS3L40S FAQ

1.How can I place an order for STPS3L40S through Aetrix?

Please submit a Request for Quotation (RFQ) for STPS3L40S 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 STPS3L40S reliable?

The price and inventory of STPS3L40S are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STPS3L40S is usually 5 days.

3.What payment methods are accepted for STPS3L40S?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STPS3L40S transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for STPS3L40S?

STPS3L40S orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your STPS3L40S 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 STPS3L40S?

For technical support, including STPS3L40S datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STPS3L40S requirements.

6.How does Aetrix verify that STPS3L40S is sourced from the original manufacturer or authorized distributors?

All STPS3L40S 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 STPS3L40S meets industry standards.

7.What is the process for return or replacement of STPS3L40S?

All STPS3L40S units undergo pre-shipment inspection (PSI). If there is an issue with STPS3L40S, 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 STPS3L40S part is unused and in its original packaging.

Return procedure for STPS3L40S:

1.Submit a request within 90 days.

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

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