STMicroelectronics STPS20120D

Overview

STPS20120D from STMicroelectronics is a 120 V, 20 A average forward current Schottky rectifier in TO-220AC package, optimized for high-frequency switch-mode power supplies. It delivers low forward voltage drop (0.72 V typ. at 20 A, 125 °C), avalanche-rated operation (619 W peak), and high junction temperature capability (175 °C), enabling use in notebook/LCD adapters and desktop SMPS where thermal margin and conduction loss reduction are critical.

For engineers reviewing the STPS20120D datasheet, STPS20120D pinout, STPS20120D application, or STPS20120D equivalent, key selection criteria include reverse leakage current (≤10 mA at 125 °C, V_RRM), junction-to-case thermal resistance (2.2 °C/W), and avalanche energy handling under transient conditions.

Technical Context

This single-diode Schottky rectifier operates without minority-carrier storage, enabling zero reverse recovery time and minimal switching losses in high-frequency DC/DC converters. Its metal–semiconductor junction provides low forward voltage (0.54–0.76 V across 25–125 °C at 20 A) while maintaining controlled reverse leakage (≤10 mA at 125 °C).

The device is rated for repetitive peak reverse voltage of 120 V and surge non-repetitive forward current up to 200 A (10 ms sinusoidal). Thermal design relies on conduction cooling via the TO-220AC case, with R_th(j-c) = 2.2 °C/W enabling stable operation at T_j ≤ 175 °C when mounted on an appropriate heatsink.

Key Specifications

Pinout & Package

STPS20120D is housed in a TO-220AC package with insulated case (no electrical connection to tab), designed for conduction cooling. The package meets UL 94 V0 flammability rating and features standardized mechanical dimensions per ST's DS4232 Rev 2 specification.

Key Features

Applications

Equivalent & Alternatives

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

Compared with VS-20SQ120 and MBR20120CT, STPS20120D offers superior thermal resistance (2.2 vs. 2.5 °C/W), guaranteed avalanche capability, and tighter V_F distribution-making it optimal for thermally aggressive, high-reliability SMPS designs where margin and longevity are critical.

Availability

STPS20120D is available at Aetrix Electronics and suitable for notebook adapters, desktop SMPS, LCD monitor power supplies, and LED lighting drivers requiring stable component supply and long-term lifecycle support.

Supply support for STPS20120D 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.

STPS20120D belongs to ST's high-voltage Schottky rectifier product line, engineered specifically for high-efficiency, high-reliability AC/DC and DC/DC conversion in space-constrained, thermally demanding power adapters and computing supplies.

FAQ

Is STPS20120D suitable for synchronous rectification?

No-STPS20120D is a passive Schottky rectifier, not a MOSFET-based synchronous rectifier controller or driver. It functions as a unidirectional conduction device with zero reverse recovery, but requires no gate drive signal. For synchronous rectification, discrete MOSFETs or dedicated SR controllers (e.g., STSR3) must be used in conjunction with this diode's placement as a freewheeling or clamp element.

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

The manufacturer specifies a recommended torque of 0.55 N·m and a maximum allowable torque of 0.70 N·m when securing the TO-220AC tab to a heatsink. Exceeding 0.70 N·m risks mechanical damage to the package leads or internal die attach, potentially degrading thermal performance or causing latent failure under thermal cycling.

Does STPS20120D require a thermal pad or insulator when mounted to a heatsink?

No-the TO-220AC package features an electrically insulated case (ceramic or polymer coating), so no additional thermal pad or insulator is required for electrical isolation. However, a thermally conductive interface material (e.g., silicone grease or phase-change pad) is strongly recommended between the tab and heatsink to minimize R_th(c-hs) and maintain junction temperature below 175 °C under full load.

How does STPS20120D's avalanche rating impact system-level reliability?

Its 619 W peak avalanche power rating (at 10 µs, T_j = 125 °C) enables safe clamping of inductive energy during unexpected switch turn-off events-such as MOSFET short-circuit or gate driver failure-in flyback and forward converters. This prevents catastrophic voltage overshoot beyond 120 V, protecting downstream capacitors and ICs without requiring external snubbers in many designs.