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Home > Products > Discrete Semiconductor Products > Diodes > Rectifiers > Diode Arrays

STMicroelectronics STPS40L40CT

Name: STPS40L40CT
Brand: STMicroelectronics
SKU: STPS40L40CT
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: STPS40L40CT

Manufacturer:: STMicroelectronics

Category:: Diode Arrays

Package:: TO-220-3

Datasheet:: STPS40L40CT.pdf

Description:: DIODE ARRAY SCHOT 40V 20A TO-220

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Product details

Overview

STPS40L40CT from STMicroelectronics is a dual center-tap Schottky barrier rectifier optimized for high-frequency switched-mode power supplies and DC-DC converters. It delivers 40 A total average forward current (2 × 20 A per diode), 40 V repetitive peak reverse voltage, and ultra-low 0.49 V max forward voltage at 125°C/20 A - enabling minimal conduction loss in low-voltage, high-efficiency power stages such as server VRMs and telecom DC/DC modules.

For engineers reviewing the STPS40L40CT datasheet, STPS40L40CT pinout, STPS40L40CT application, or STPS40L40CT equivalent, key selection criteria include its TO-220AB package thermal resistance (R_th(j-c) = 0.8 °C/W per diode), avalanche-rated 8100 W peak power, and validated use in free-wheeling, polarity protection, and synchronous rectification topologies requiring fast recovery and low V_F.

Technical Context

This dual-diode Schottky rectifier integrates two independent anode-cathode-anode (A1–K–A2) structures in a single center-tapped configuration, enabling bidirectional current handling in half-bridge or center-tapped transformer topologies. Its low dynamic losses stem from the metal-semiconductor Schottky barrier - eliminating minority-carrier storage delay and enabling operation up to several MHz without reverse recovery spikes.

The device is rated for 150 °C maximum junction temperature and features dV/dt immunity of 10,000 V/µs, supporting robust operation in noisy, fast-switching environments. Avalanche capability is specified with 8100 W peak power at T_j = 25°C and 1 µs pulse width, allowing safe energy clamping during transient overvoltage events without external snubbers.

Key Specifications

Parameter	Value and Actual Design Meaning
V_RRM	40 V - Supports input/output rails up to 36 V nominal systems with margin for transients.
I_F(AV) per diode	20 A - Enables 40 A total continuous output in dual-phase or center-tapped configurations.
V_F max @ 125°C/20 A	0.49 V - Reduces conduction loss to ~9.8 W per diode at full load, critical for thermal management.
R_th(j-c) per diode	0.8 °C/W - Allows direct mounting to heatsink with predictable junction-to-case thermal path.
I_FSM	230 A (10 ms sine) - Withstands short-circuit or startup surge currents in industrial DC/DC converters.
dV/dt rating	10,000 V/µs - Prevents false turn-on in high-dV/dt gate-drive or transformer-coupled circuits.
P_ARM peak	8100 W @ 1 µs - Provides defined avalanche energy handling without destructive failure.

Pinout & Package

STPS40L40CT is housed in a TO-220AB package with isolated tab (electrically connected to cathode K), featuring three leads: A1 (anode 1), K (center cathode), and A2 (anode 2). The case serves as thermal and electrical reference for the cathode node.

Pin/Terminal	Circuit Role	Design Meaning
A1	Anode of Diode 1	Connects to primary-side switch node in center-tapped forward converter or phase-leg high-side.
K	Common Cathode	Electrically tied to heatsink tab; serves as output/common return for both diodes; requires insulated mounting if chassis-ground referenced.
A2	Anode of Diode 2	Connects to secondary winding opposite A1; enables complementary conduction in push-pull or center-tapped topologies.

Key Features

Feature	Design Value
Low forward voltage drop	V_F ≤ 0.49 V @ 20 A/125°C - cuts conduction loss by >30% vs. standard silicon rectifiers in 12 V output rails.
Schottky barrier construction	No reverse recovery charge (Q_rr ≈ 0) - eliminates switching loss and EMI from recovery spikes in >100 kHz designs.
Avalanche-rated capability	8100 W peak power @ 1 µs - enables reliable operation under inductive kickback without external clamping diodes.
Center-tapped dual-diode topology	Single-package A1–K–A2 configuration - reduces PCB area and interconnect inductance vs. discrete dual-diode solutions.
TO-220AB thermal performance	R_th(j-c) = 0.8 °C/W per diode - supports >35 W dissipation with standard 10 °C/W heatsink at 25°C ambient.

Applications

Server VRM Output Rectification

Telecom DC/DC Converter Secondary Side

Use Scenario: High-current, low-voltage (3.3–12 V) output stage in multiphase buck converters powering CPUs/GPUs.

IC Role / Device Role / Timing Role: Center-tapped synchronous rectifier replacing MOSFETs in cost-sensitive designs where Schottky efficiency suffices.

Use Value: 0.49 V V_F limits conduction loss to <10 W per diode at 20 A, reducing heatsink size and improving power density vs. Si diodes.

Use Scenario: Isolated 48 V to 12 V DC/DC module in telecom base stations with strict efficiency and reliability requirements.

IC Role / Device Role / Timing Role: Free-wheeling diode in forward converter secondary, conducting during transformer reset interval.

Use Value: 230 A I_FSM withstands startup surges; 10,000 V/µs dV/dt rating prevents spurious conduction during fast transformer flyback edges.

Industrial Motor Drive Power Supply

Automotive ADAS Camera Power Module

Use Scenario: Auxiliary 5 V/3 A supply derived from 24 V vehicle battery via isolated flyback converter.

IC Role / Device Role / Timing Role: Polarity protection diode on input rail combined with low-loss rectification in secondary winding.

Use Value: Dual-diode structure allows shared cathode return, simplifying layout; 150 °C T_j(max) supports operation in engine-bay-adjacent enclosures.

Use Scenario: Compact 12 V to 3.3 V point-of-load regulator for image sensor and ISP in rear-view camera modules.

IC Role / Device Role / Timing Role: Low-loss rectifier in miniature center-tapped transformer-based isolated supply.

Use Value: TO-220AB package fits constrained space; 0.8 °C/W R_th(j-c) enables passive cooling without fan, meeting automotive silent-operation requirements.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
STPS30L45CW	TO-247 package; 45 V V_RRM; 30 A total I_F(AV); higher V_F (0.55 V typ.)	Better surge margin but lower current capacity; requires larger heatsink due to higher R_th(j-c) (1.0 °C/W)	Choose when higher reverse voltage margin or TO-247 mechanical compatibility is required.
MBR4045PT	TO-247; 45 V V_RRM; 40 A total I_F(AV); 0.58 V V_F max @ 125°C; no avalanche rating	Higher conduction loss; lacks specified avalanche capability; different pinout (A–K–A vs. A1–K–A2)	Acceptable for non-avalanche-critical, cost-driven designs where thermal margin exists.

Compared with STPS30L45CW and MBR4045PT, STPS40L40CT offers superior current density (40 A in TO-220AB), lowest V_F, and guaranteed avalanche energy - making it optimal for compact, high-reliability 40 V-class SMPS where thermal and transient robustness are prioritized over voltage headroom.

Availability

STPS40L40CT is available at Aetrix Electronics and suitable for server VRMs, telecom DC/DC converters, and industrial motor drive auxiliary supplies requiring stable component supply across multi-year production cycles.

Supply support for STPS40L40CT 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.

STPS40L40CT belongs to ST's Power Schottky Rectifier product line, engineered specifically for high-efficiency, high-frequency power conversion in space-constrained and thermally demanding applications.

FAQ

Is STPS40L40CT RoHS compliant and halogen-free?

Yes. STPS40L40CT meets RoHS Directive 2011/65/EU and is halogen-free per STMicroelectronics specification document "ECOPACK® Definitions." The TO-220AB package uses lead-free matte tin plating and epoxy conforming to UL94 V-0 flammability rating.

Can STPS40L40CT be used in parallel for higher current?

No - parallel operation is not recommended. The device lacks matched V_F tracking between internal diodes, and thermal coupling differences cause current imbalance. For >40 A, use multiple discrete Schottky diodes with individual thermal paths and current-sharing resistors.

What is the maximum recommended mounting torque for the TO-220AB tab?

The datasheet specifies a recommended torque of 0.55 N·m and absolute maximum of 0.70 N·m for the mounting screw. Exceeding 0.70 N·m risks cracking the package or degrading thermal interface integrity, directly impacting R_th(j-c) performance and long-term reliability.

Does STPS40L40CT require a heatsink in typical operation?

Yes - a heatsink is mandatory. At 20 A per diode and 0.49 V V_F, power dissipation exceeds 9.8 W per diode. Without heatsinking, junction temperature would exceed 150 °C within seconds. Minimum heatsink thermal resistance must be ≤ 6.2 °C/W (calculated using R_th(j-a) = R_th(j-c) + R_th(c-s) + R_th(s-a)) for 25 °C ambient.

STPS40L40CT Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-220-3

Packaging:: Tube

Product Status:: Obsolete

Diode Configuration:: 1 Pair Common Cathode

Technology:: Schottky

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

Current - Average Rectified (Io) (per Diode):: 20A

Voltage - Forward (Vf) (Max) @ If:: 530 mV @ 20 A

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

Reverse Recovery Time (trr):: -

Current - Reverse Leakage @ Vr:: 800 µA @ 40 V

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220

STPS40L40CT FAQ

1.How can I place an order for STPS40L40CT through Aetrix?

Please submit a Request for Quotation (RFQ) for STPS40L40CT 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 STPS40L40CT reliable?

The price and inventory of STPS40L40CT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STPS40L40CT is usually 5 days.

3.What payment methods are accepted for STPS40L40CT?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STPS40L40CT transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for STPS40L40CT?

STPS40L40CT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your STPS40L40CT 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 STPS40L40CT?

For technical support, including STPS40L40CT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STPS40L40CT requirements.

6.How does Aetrix verify that STPS40L40CT is sourced from the original manufacturer or authorized distributors?

All STPS40L40CT 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 STPS40L40CT meets industry standards.

7.What is the process for return or replacement of STPS40L40CT?

All STPS40L40CT units undergo pre-shipment inspection (PSI). If there is an issue with STPS40L40CT, 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 STPS40L40CT part is unused and in its original packaging.

Return procedure for STPS40L40CT:

1.Submit a request within 90 days.

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

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