STMicroelectronics STPS20L15D

Overview

STPS20L15D from STMicroelectronics is a low-drop OR-ing Schottky diode in TO-220AC package, rated for 20 A average forward current and 15 V repetitive peak reverse voltage, with typical forward voltage of 0.28 V at 19 A and 125 °C junction temperature, designed for fault-tolerant 3 V/5 V/12 V rail OR-ing in redundant power supplies.

For engineers reviewing the STPS20L15D datasheet, STPS20L15D pinout, STPS20L15D application, or STPS20L15D equivalent, key selection criteria include forward voltage drop at high current and elevated temperature, avalanche energy rating (970 W at 10 µs), thermal resistance (1.6 °C/W junction-to-case), and compliance with ECOPACK®2 environmental requirements.

Technical Context

This device operates as a unidirectional power path selector in redundant DC power architectures, enabling seamless switchover between parallel supplies without reverse current flow. Its Schottky barrier construction eliminates minority-carrier storage delay and supports fast transient response during supply failure events.

It features specified avalanche capability (970 W, 10 µs pulse, Tj = 125 °C) and is characterized for stable operation up to 125 °C junction temperature under continuous conduction, with thermal runaway avoidance ensured when (dPtot/dTj) < (1/Rth(j-a)) on heatsink.

Key Specifications

Pinout & Package

STPS20L15D is housed in a TO-220AC package with isolated tab (case), featuring two terminals: anode and cathode. The metal tab is electrically connected to the cathode and serves as the primary thermal interface.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar OR-ing diode applications.

Compared with STPS20L15G, STPS20L15D offers identical electrical performance but simplified mechanical mounting and higher thermal mass; versus MBR2015CT, it delivers superior reliability in hot-swap and inductive-load environments due to guaranteed avalanche energy and lower VF at operating temperature.

Availability

STPS20L15D is available at Aetrix Electronics and suitable for telecom power shelf OR-ing, industrial PLC redundant PSU, and server midplane power combining requiring stable component supply across multi-year production cycles.

Supply support for STPS20L15D 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, designing and manufacturing analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

STPS20L15 belongs to ST's high-reliability power Schottky diode product line, engineered specifically for fault-tolerant OR-ing in redundant DC power systems where low VF, avalanche robustness, and thermal stability are critical.

FAQ

What is the maximum recommended torque for mounting STPS20L15D?

The recommended torque value for STPS20L15D's TO-220AC package is 0.55 N·m; maximum allowable torque is 0.7 N·m. Exceeding this may deform the case or compromise internal bond wire integrity. Use calibrated torque screwdrivers and insulating shoulder washers when mounting to grounded heatsinks.

Does STPS20L15D require a heatsink in all applications?

Yes - STPS20L15D must be mounted to a heatsink via its cathode-connected tab to maintain Tj ≤ 125 °C at rated 20 A IF(AV). With Rth(j-c) = 1.6 °C/W and typical conduction loss ~5.3 W at 20 A, even modest ambient temperatures require ≥10 cm² copper area or active cooling to avoid thermal runaway.

Is STPS20L15D suitable for reverse polarity protection?

No - STPS20L15D is optimized for forward-biased OR-ing, not reverse-polarity blocking. Its 15 V VRRM is insufficient for most input protection schemes, and its avalanche rating applies only to controlled reverse-bias transients during OR-ing, not sustained reverse voltage exposure.

How does the 0.28 V VF spec relate to actual power loss?

At 19 A and 125 °C, 0.28 V VF yields ~5.3 W conduction loss (P = VF × IF). Using ST's provided equation P = 0.18 × IF(AV) + 8×10⁻³ × IF²(RMS), loss at 20 A DC is ~5.2 W - confirming low thermal burden and enabling compact thermal design in space-constrained OR-ing nodes.