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

STMicroelectronics STPS1L40U

Name: STPS1L40U
Brand: STMicroelectronics
SKU: STPS1L40U
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: STPS1L40U

Manufacturer:: STMicroelectronics

Category:: Single Diodes

Package:: DO-214AA, SMB

Datasheet:: STPS1L40U.pdf

Description:: DIODE SCHOTTKY 40V 1A SMB

Quantity:: RFQ Add To RFQ list

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Inventory:7,997

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Product details

Overview

STPS1L40U from STMicroelectronics is a 40 V, 1 A low-drop Schottky rectifier in SMB package, optimized for high-frequency DC-DC converters and reverse polarity protection circuits with VF(typ.) = 0.37 V at 125 °C and Tj(max.) = 175 °C. It delivers negligible switching losses and very small conduction losses in TV power supplies and set-top box applications.

For engineers reviewing the STPS1L40U datasheet, STPS1L40U pinout, STPS1L40U application, or STPS1L40U equivalent, key selection criteria include forward voltage drop at 1 A/125 °C, avalanche rating (65 W), thermal resistance (Rth(j-l) = 25 °C/W), junction temperature limit, and ECOPACK2 compliance for surface-mount reliability.

Technical Context

This single-die Schottky rectifier uses platinum-silicide barrier technology to achieve low VF and fast recovery without minority-carrier storage. Its 40 V VRRM rating targets low-voltage secondary-side rectification in SMPS where efficiency and thermal margin are critical.

The device is avalanche-rated (65 W, tp = 10 µs at Tj = 125 °C) and supports continuous operation up to 175 °C junction temperature. Package-specific thermal resistances (e.g., Rth(j-l) = 25 °C/W for SMB) directly define maximum ambient temperature derating under defined PCB copper area.

Key Specifications

Parameter	Value and Actual Design Meaning
VRRM	40 V - Maximum repetitive reverse voltage before breakdown; sets safe operating range in 12–24 V output rails.
IF(AV)	1 A - Average forward current at TL = 155 °C (SMB); defines steady-state power delivery capability.
VF(typ.)	0.37 V at IF = 1 A, Tj = 125 °C - Directly determines conduction loss (P ≈ 0.37 W) and thermal load in high-duty-cycle apps.
Tj(max.)	175 °C - Maximum junction temperature; enables operation in thermally constrained enclosures like sealed TVs.
Rth(j-l)	25 °C/W (SMB) - Junction-to-lead thermal resistance; used with PCB copper area to calculate real-world thermal rise.
IR(max.)	10 mA at VR = 40 V, Tj = 125 °C - Reverse leakage limits standby power loss in battery-backed or always-on systems.
PARM	65 W (tp = 10 µs) - Repetitive avalanche power rating; ensures robustness against transient voltage spikes in flyback snubbers.

Pinout & Package

SMB package: Surface-mount, 2-terminal, cathode-banded, UL94 V0 epoxy housing. Dimensions: D = 3.30–3.95 mm, E = 5.10–5.60 mm, L = 0.75–1.50 mm. Lead-free, ECOPACK2 compliant.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Forward current entry point	Connected to lower-potential node (e.g., ground side of transformer secondary); must handle 60 A surge (IFSM).
Cathode	Forward current exit / reverse-blocking terminal	Banded end; connects to positive rail; sustains 40 V reverse bias and dissipates reverse leakage <10 mA at 125 °C.

Key Features

Feature	Design Value
Low VF at high temperature	0.37 V @ 1 A, 125 °C - Reduces conduction loss by ~30% vs. standard Schottkys, improving efficiency in warm environments.
Avalanche energy rating	65 W @ 10 µs - Enables reliable operation without external clamping in inductive switching nodes (e.g., freewheeling paths).
High junction temperature limit	175 °C - Allows use in compact, sealed power supplies where heatsinking is impractical (e.g., slim TVs).
ECOPACK2 compliance	Lead-free, halogen-free, RoHS-compliant packaging - Meets global environmental regulations without performance trade-offs.
Multiple package options	SMB footprint (STPS1L40U) - Standardized 5.6 × 3.95 mm land pattern compatible with automated SMT assembly and IPC-7351B.

Applications

Reverse Polarity Protection

TV Power Supply Secondary Rectification

Use Scenario: Prevents damage when external 12 V DC input is connected with reversed polarity to a mainboard.

IC Role / Device Role / Timing Role: Low-loss series blocking diode placed between connector and input capacitor.

Use Value: 0.37 V forward drop minimizes voltage loss and heat generation at 1 A, preserving system efficiency and enabling smaller PCB area.

Use Scenario: Rectifies high-frequency (100–500 kHz) transformer output in a 12 V/2 A secondary stage of an LED TV power supply.

IC Role / Device Role / Timing Role: High-speed unidirectional current path replacing slower PN diodes to reduce switching losses.

Use Value: Negligible reverse recovery time eliminates turn-off spikes, easing EMI filter design and improving overall converter efficiency.

Set-Top Box Standby Power Rectification

Battery Charger Output Stage

Use Scenario: Provides isolated 3.3 V standby rail from auxiliary winding in a quasi-resonant flyback converter.

IC Role / Device Role / Timing Role: Freewheeling diode conducting during MOSFET off-time; handles square-wave current with δ = 0.5 duty cycle.

Use Value: 175 °C max junction temperature allows sustained operation in confined chassis with minimal airflow, supporting long-term reliability.

Use Scenario: Rectifies AC-DC adapter output before Li-ion battery charging IC in portable media players.

IC Role / Device Role / Timing Role: Output rectifier ensuring minimal voltage drop across charging path to maximize charge voltage accuracy.

Use Value: 10 mA max reverse leakage at 125 °C prevents significant self-discharge during hot storage, extending shelf life.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
SS14 (Diodes Inc.)	VRRM = 40 V, IF(AV) = 1 A, VF = 0.5 V @ 1 A, 25 °C; no avalanche rating; Rth(j-l) = 30 °C/W (SMA)	Lacks avalanche robustness and higher VF increases conduction loss by ~0.13 V at 125 °C	Acceptable only in non-critical, low-transient, well-cooled designs where cost is primary driver.
SB140 (ON Semiconductor)	VRRM = 40 V, IF(AV) = 1 A, VF = 0.55 V @ 1 A, 25 °C; Tj(max.) = 125 °C; not ECOPACK2 certified	Lower max junction temperature restricts use in thermally dense layouts; higher VF degrades efficiency	Only suitable for legacy designs requiring identical footprint but accepting reduced thermal margin and environmental compliance.

Compared with SS14 and SB140, STPS1L40U provides superior thermal capability (175 °C vs. ≤125 °C), lower VF at operating temperature, and verified avalanche energy handling-critical for reliability in consumer power supplies exposed to line transients and thermal cycling.

Availability

STPS1L40U is available at Aetrix Electronics and suitable for TV power supplies, set-top box secondary rectification, and reverse polarity protection circuits requiring stable component supply, consistent lead-free compliance, and high-temperature reliability.

Supply support for STPS1L40U 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 automotive, industrial, and consumer markets.

STPS1L40U belongs to ST's high-efficiency Schottky rectifier product line, engineered specifically for low-voltage, high-frequency SMPS in space-constrained consumer electronics where thermal resilience and low conduction loss are mandatory.

FAQ

What is the maximum allowable ambient temperature for STPS1L40U at 1 A DC in free air?

At 1 A average forward current and δ = 0.5, the SMB-packaged STPS1L40U reaches thermal equilibrium at approximately 105 °C ambient on a standard FR4 board with 1 cm² copper per lead (Rth(j-a) ≈ 65 °C/W). Derating curves in Figure 3 confirm usable operation up to 125 °C ambient with adequate PCB copper area.

Does STPS1L40U require a heatsink in typical TV power supply applications?

No heatsink is required. With Rth(j-l) = 25 °C/W and typical PCB copper (≥2 cm² per lead), junction temperature remains below 120 °C at 1 A/125 °C ambient. The device relies on conduction cooling through leads into PCB copper, as validated in AN5088 for SMA/SMB rectifiers.

How does the avalanche rating of STPS1L40U improve system reliability?

The 65 W repetitive avalanche rating (tp = 10 µs, Tj = 125 °C) allows the diode to safely absorb inductive energy spikes-such as those from transformer leakage in flyback converters-without failure. This eliminates need for external TVS or RC snubbers in many consumer-grade SMPS designs.

Is STPS1L40U pin-compatible with other SMB Schottky rectifiers like SS14?

Yes-STPS1L40U uses standard SMB package dimensions (E = 5.10–5.60 mm, D = 3.30–3.95 mm) matching JEDEC DO-214AA, making it mechanically interchangeable with SS14, SB140, and MBR140. However, electrical differences (VF, Tj(max.), avalanche rating) require validation in final circuit operation.

STPS1L40U Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: DO-214AA, SMB

Packaging:: Tape & Reel (TR)

Product Status:: Active

Technology:: Schottky

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

Current - Average Rectified (Io):: 1A

Voltage - Forward (Vf) (Max) @ If:: 500 mV @ 1 A

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

Reverse Recovery Time (trr):: -

Current - Reverse Leakage @ Vr:: 35 µA @ 40 V

Capacitance @ Vr, F:: -

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SMB

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

STPS1L40U FAQ

1.How can I place an order for STPS1L40U through Aetrix?

Please submit a Request for Quotation (RFQ) for STPS1L40U 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 STPS1L40U reliable?

The price and inventory of STPS1L40U are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STPS1L40U is usually 5 days.

3.What payment methods are accepted for STPS1L40U?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STPS1L40U transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for STPS1L40U?

STPS1L40U orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your STPS1L40U 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 STPS1L40U?

For technical support, including STPS1L40U datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STPS1L40U requirements.

6.How does Aetrix verify that STPS1L40U is sourced from the original manufacturer or authorized distributors?

All STPS1L40U 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 STPS1L40U meets industry standards.

7.What is the process for return or replacement of STPS1L40U?

All STPS1L40U units undergo pre-shipment inspection (PSI). If there is an issue with STPS1L40U, 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 STPS1L40U part is unused and in its original packaging.

Return procedure for STPS1L40U:

1.Submit a request within 90 days.

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

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