STMicroelectronics STPS40SM100CT

Overview

STPS40SM100CT from STMicroelectronics is a dual common-cathode 100 V, 40 A (per device) Schottky power rectifier in TO-220AB package, optimized for high-frequency switching in notebook and game station AC/DC adapters. It delivers typ. 0.605 V forward voltage at 20 A/125 °C, supports 150 °C max junction temperature, and features avalanche-rated capability (1295 W, 10 µs).

For engineers reviewing the STPS40SM100CT datasheet, STPS40SM100CT pinout, STPS40SM100CT application, or STPS40SM100CT equivalent, key selection criteria include low conduction loss (VF vs. IF curves), thermal coupling behavior between dual diodes, reverse leakage at 125 °C, and TO-220AB mounting torque specification (0.55 N·m recommended).

Technical Context

This dual-diode Schottky rectifier integrates two independent 20 A diodes sharing a common cathode terminal, enabling synchronous or interleaved operation in center-tapped or full-wave bridge configurations. Its low VF–IR trade-off is achieved via optimized metal-silicon barrier design, with specified avalanche energy handling (1295 W, 10 µs pulse) confirming ruggedness under transient overvoltage.

Thermal architecture uses coupled junction-to-case resistance (Rth(j-c) = 0.7 °C/W total, 1.3 °C/W per diode; Rth(c) = 0.1 °C/W coupling), requiring explicit derating when both diodes conduct simultaneously-designers must apply ΔTj(diode1) = P₁×1.3 + P₂×0.1 to avoid thermal runaway.

Key Specifications

Pinout & Package

Package: TO-220AB - Insulated plastic case with metal tab (cathode-connected), designed for conduction cooling via heatsink mounting (recommended torque: 0.55 N·m). Dimensions per DS6173 Rev 4: D = 15.25–15.75 mm, E = 10.00–10.40 mm, L = 13.00–14.00 mm.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual common-cathode Schottky rectifier applications.

Compared with VS-40CPH01-M3 and MBR40100CT, STPS40SM100CT provides superior thermal coupling control, lower conduction loss, and guaranteed avalanche ruggedness-making it the preferred choice for compact, high-reliability AC/DC adapters where board area and transient immunity are constrained.

Availability

STPS40SM100CT is available at Aetrix Electronics and suitable for AC/DC adapters, notebook power supplies, and industrial DC/DC converters requiring stable component supply, long-term lifecycle support, and traceable ECOPACK®2-compliant sourcing.

Supply support for STPS40SM100CT 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.

The STPS40SM100CT belongs to ST's high-efficiency Schottky rectifier product line, engineered specifically for high-frequency, high-density AC/DC and DC/DC power conversion in portable and entertainment electronics.

FAQ

What is the thermal coupling effect between the two diodes in STPS40SM100CT?

The device specifies Rth(c) = 0.1 °C/W coupling resistance between diodes. When both conduct simultaneously, junction temperature rise of Diode 1 equals P₁×1.3 + P₂×0.1. This requires explicit derating in dual-rail designs-e.g., 15 A per anode raises Tj by 22.5 °C above ambient, not 19.5 °C as with isolated diodes.

Can STPS40SM100CT replace a single 40 A Schottky in a full-wave bridge?

No-it is a dual common-cathode configuration, not a full-bridge. It replaces two discrete 20 A Schottkys in center-tapped or dual-output topologies. For bridge rectification, two STPS40SM100CT units would be needed (four anodes total), increasing cost and footprint versus dedicated bridge packages.

Is the TO-220AB tab electrically isolated?

No-the metal tab is internally connected to the common cathode. Electrical isolation from the heatsink or chassis requires insulating hardware (e.g., mica washer + nylon screw) unless the cathode node is at system ground potential. Mounting torque must stay within 0.55–0.70 N·m to avoid die fracture.

How does the 1295 W avalanche rating translate to real-world circuit protection?

This rating applies to 10 µs pulses at Tj = 125 °C and confirms the device can absorb 12.95 mJ per pulse without failure. In practice, it protects against flyback transformer leakage inductance spikes up to 100 V × 129.5 A peak, eliminating need for external clamping diodes in properly designed 90–100 W adapters.