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

STMicroelectronics STPS20M120STN

Name: STPS20M120STN
Brand: STMicroelectronics
SKU: STPS20M120STN
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: STPS20M120STN

Manufacturer:: STMicroelectronics

Category:: Single Diodes

Package:: TO-220-3

Datasheet:: STPS20M120STN.pdf

Description:: DIODE SCHOTT 120V 20A TO220AB

Quantity:: RFQ Add To RFQ list

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Inventory:4,317

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Product details

Overview

STPS20M120STN from STMicroelectronics is a 120 V, 20 A average forward current Schottky rectifier in TO-220AB narrow leads package, featuring 0.63 V typical forward voltage at 20 A and 125 °C, avalanche-rated operation, and ECOPACK®2 compliance. It serves as a high-efficiency output rectifier in notebook adapters, desktop power supplies, and LED drivers where low conduction loss and high-frequency switching are critical.

For engineers reviewing the STPS20M120STN datasheet, STPS20M120STN pinout, STPS20M120STN application, or STPS20M120STN equivalent, key selection criteria include repetitive peak reverse voltage (120 V), thermal resistance junction-to-case (1.35 °C/W), surge current capability (240 A), avalanche power rating (1200 W), and low VF drift over temperature.

Technical Context

This Schottky diode employs a planar silicon structure optimized for fast recovery and minimal reverse recovery charge, enabling efficient operation in high-frequency SMPS topologies up to several hundred kHz. Its low forward voltage drop and high junction temperature rating (+150 °C) support compact thermal design in space-constrained AC/DC adapters.

The device is avalanche-rated per IEC 61000-4-5 with 1200 W repetitive peak avalanche power at 10 µs pulse width and Tj = 125 °C, allowing robust transient handling without external snubbers in DC/DC converter secondary-side rectification.

Key Specifications

Parameter	Value and Actual Design Meaning
V_RRM	120 V - Maximum repetitive reverse blocking voltage; defines safe operating range in 12 V–24 V output DC/DC converters with 20% input ripple margin.
I_F(AV)	20 A - Average forward current at T_C = 125 °C; supports continuous 48 W output at 2.4 V drop in 24 V systems.
V_F (typ)	0.63 V @ 20 A, 125 °C - Low conduction loss enables >94% efficiency in 19 V/3 A notebook adapters.
R_th(j-c)	1.35 °C/W - Enables 75 °C junction rise above case at 20 A, permitting use with small heatsinks in slim adapters.
I_FSM	240 A @ 10 ms - Withstands inrush and short-circuit surges in unregulated secondary rails without failure.
P_ARM	1200 W @ 10 µs - Avalanche energy rating allows safe clamping of inductive spikes in synchronous rectifier gate-drive circuits.

Pinout & Package

TO-220AB narrow leads package: 3-terminal through-hole housing with isolated tab (anode), cathode, and cathode (dual cathode pins). Mounting via M3 screw with 0.55 N·m recommended torque; thermal path from junction to case via copper leadframe and metal tab.

Pin/Terminal	Circuit Role	Design Meaning
Tab (Anode)	Anode connection	Electrically and thermally connected to internal die anode; must be electrically isolated from heatsink unless system ground referenced.
Pin 1 (Cathode)	Cathode connection	Primary cathode terminal; carries full forward current; bonded directly to cathode metallization.
Pin 2 (Cathode)	Cathode connection	Secondary cathode terminal; reduces series inductance and improves current sharing in high-di/dt applications.

Key Features

Feature	Design Value
Avalanche-rated operation	1200 W repetitive peak avalanche power at 10 µs ensures reliable clamping of transformer leakage spikes in flyback converters.
Low forward voltage	0.63 V typ. @ 20 A, 125 °C reduces conduction loss by ~25% vs. standard 120 V Schottkys, improving adapter efficiency at full load.
High junction temperature rating	+150 °C max operating junction temperature enables stable operation in sealed enclosures with ambient up to 85 °C.
ECOPACK®2 compliance	Halogen-free, RoHS-compliant epoxy meets global environmental regulations without compromising mechanical robustness or thermal performance.

Applications

Notebook Adapter Rectification

LED Driver Secondary Rectification

Use Scenario: 19 V/3 A output stage in ultra-slim notebook AC/DC adapters with <15 mm height constraint.

IC Role / Device Role / Timing Role: Output synchronous rectifier replacing MOSFETs in quasi-resonant flyback topology.

Use Value: 0.63 V V_F minimizes conduction loss at 20 A peak, enabling >92% efficiency at 100% load while reducing heatsink mass by 40%.

Use Scenario: Constant-current LED driver for commercial downlights with 36 V string and 700 mA output.

IC Role / Device Role / Timing Role: High-frequency freewheeling diode in buck-boost LED controller secondary path.

Use Value: 240 A I_FSM withstands startup inrush; 1.35 °C/W R_th(j-c) allows direct mounting to aluminum PCB for passive thermal management.

Desktop PC Power Supply

Industrial DC/DC Converter

Use Scenario: +12 V rail rectification in ATX PSUs with multi-phase synchronous rectification architecture.

IC Role / Device Role / Timing Role: Auxiliary Schottky clamp in active clamp forward converter secondary.

Use Value: Avalanche rating eliminates need for external TVS; 120 V V_RRM provides 50% margin over 12 V rail transients per IEC 61000-4-4.

Use Scenario: 24 V input, 5 V/10 A isolated DC/DC module for factory automation controllers.

IC Role / Device Role / Timing Role: Primary-side rectifier in half-bridge LLC resonant converter output stage.

Use Value: Dual cathode pins reduce parasitic inductance, suppressing ringing during 500 kHz switching; 150 °C T_j(max) supports derated operation in 70 °C ambient industrial cabinets.

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-20CPH12-M3	Same 120 V V_RRM, 20 A I_F(AV), but higher V_F (0.72 V typ. @ 20 A, 125 °C) and no avalanche rating.	Lacks avalanche capability; requires external clamping in flyback designs with high leakage inductance.	Select when cost sensitivity outweighs surge robustness and efficiency targets are relaxed by ≤1.2%.
ON Semiconductor SB20E120P1G	Identical TO-220AB package, 120 V/20 A rating, but 0.68 V V_F typ. and 1.55 °C/W R_th(j-c).	Higher thermal resistance limits continuous current to 17.5 A at same case temperature; less suitable for sealed adapters.	Prefer only if supply chain constraints require ON Semi sourcing; verify heatsink sizing for 125 °C T_C derating.

Compared with VS-20CPH12-M3 and SB20E120P1G, STPS20M120STN delivers superior efficiency (0.63 V V_F) and reliability (1200 W avalanche rating), making it optimal for thermally constrained, high-reliability adapter and industrial DC/DC designs where conduction loss and transient immunity are prioritized.

Availability

STPS20M120STN is available at Aetrix Electronics and suitable for notebook adapters, LED lighting drivers, and industrial DC/DC converters requiring stable component supply, long-term lifecycle support, and traceable ECOPACK®2-compliant sourcing.

Supply support for STPS20M120STN 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, power, microcontroller, and sensor solutions for automotive, industrial, and consumer markets.

STPS20M120STN belongs to ST's high-performance Schottky rectifier product line, engineered specifically for high-efficiency, high-reliability AC/DC and DC/DC power conversion in space- and thermal-constrained applications.

FAQ

What is the maximum allowable case temperature for continuous operation?

The STPS20M120STN supports continuous operation at T_C = 125 °C, as specified in its I_F(AV) rating. At this case temperature, the junction remains within its 150 °C limit due to the 1.35 °C/W R_th(j-c), yielding a 33.75 °C junction-to-case rise. Exceeding 125 °C case temperature risks thermal runaway under full load.

Does STPS20M120STN have a dual-cathode configuration, and why is it used?

Yes - STPS20M120STN features two separate cathode pins (Pin 1 and Pin 2) in its TO-220AB narrow leads package. This configuration reduces effective series inductance and improves current distribution during high-di/dt switching, minimizing voltage overshoot and EMI in >300 kHz SMPS designs.

How does the avalanche rating impact circuit protection design?

The 1200 W repetitive avalanche power rating (at 10 µs, T_j = 125 °C) allows the diode to safely absorb inductive energy from transformer leakage without external clamping components. This simplifies layout, reduces BOM count, and improves reliability in flyback and forward converters with poorly controlled leakage inductance.

Is the TO-220AB narrow leads package compatible with standard TO-220 footprints?

No - the TO-220AB narrow leads variant has reduced lead spacing (e.g., e = 2.40–2.70 mm vs. standard 2.54 mm pitch), requiring dedicated PCB land patterns. Using a standard TO-220 footprint may cause solder joint stress or misalignment; ST provides exact mechanical dimensions in DS8943 Table 4 for accurate layout.

STPS20M120STN Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-220-3

Packaging:: Tube

Product Status:: Obsolete

Technology:: Schottky

Voltage - DC Reverse (Vr) (Max):: 120 V

Current - Average Rectified (Io):: 20A

Voltage - Forward (Vf) (Max) @ If:: 840 mV @ 20 A

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

Reverse Recovery Time (trr):: -

Current - Reverse Leakage @ Vr:: 275 µA @ 120 V

Capacitance @ Vr, F:: -

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220AB Narrow Leads

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

STPS20M120STN FAQ

1.How can I place an order for STPS20M120STN through Aetrix?

Please submit a Request for Quotation (RFQ) for STPS20M120STN 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 STPS20M120STN reliable?

The price and inventory of STPS20M120STN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STPS20M120STN is usually 5 days.

3.What payment methods are accepted for STPS20M120STN?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STPS20M120STN transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for STPS20M120STN?

STPS20M120STN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your STPS20M120STN 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 STPS20M120STN?

For technical support, including STPS20M120STN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STPS20M120STN requirements.

6.How does Aetrix verify that STPS20M120STN is sourced from the original manufacturer or authorized distributors?

All STPS20M120STN 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 STPS20M120STN meets industry standards.

7.What is the process for return or replacement of STPS20M120STN?

All STPS20M120STN units undergo pre-shipment inspection (PSI). If there is an issue with STPS20M120STN, 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 STPS20M120STN part is unused and in its original packaging.

Return procedure for STPS20M120STN:

1.Submit a request within 90 days.

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

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