STMicroelectronics STPS30120CT

Overview

STPS30120CT from STMicroelectronics is a dual center-tap Schottky rectifier in TO-220AB package, rated for 120 V repetitive peak reverse voltage and 2 × 15 A average forward current per diode at Tc = 145 °C, with typical forward voltage drop of 0.70 V at 15 A and 125 °C, optimized for high-frequency SMPS in notebook/LCD adaptors and desktop power supplies.

For engineers reviewing the STPS30120CT datasheet, STPS30120CT pinout, STPS30120CT application, or STPS30120CT equivalent, key selection criteria include avalanche rating (480 W at 10 µs), low leakage (≤7.5 mA at 125 °C, VR = 120 V), thermal resistance (Rth(j-c) = 2.2 °C/W per diode), junction temperature capability (175 °C max), and ECOPACK®2 compliance.

Technical Context

This dual common-cathode Schottky rectifier integrates two identical 120 V/15 A diodes sharing a single cathode terminal, enabling center-tap transformer secondary rectification without external parallel wiring. Its low VF–IR trade-off minimizes conduction loss while maintaining acceptable reverse leakage under high ambient temperatures.

The device supports avalanche energy absorption up to 480 W for 10 µs pulses at 125 °C junction temperature, and features a junction-to-case thermal resistance of 2.2 °C/W per diode - critical for heatsink-limited designs in compact AC-DC adapters where thermal coupling between diodes must be modeled using Rth(c) = 0.3 °C/W.

Key Specifications

Pinout & Package

STPS30120CT is housed in a TO-220AB package with three leads: two anodes (A1, A2) and one common cathode (K). The package uses epoxy meeting UL 94 V0 flammability rating and is cooled by conduction via the metal tab (cathode-connected). Recommended mounting torque is 0.55 N·m.

Key Features

Applications

Equivalent & Alternatives

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

Compared with VB22020 and SS312H, STPS30120CT delivers superior thermal resilience (175 °C Tj), verified avalanche ruggedness (480 W), and lowest VF at high temperature - making it the preferred choice for high-reliability, high-power-density SMPS where thermal and transient margins are critical.

Availability

STPS30120CT is available at Aetrix Electronics and suitable for notebook adaptors, LCD monitor power supplies, and industrial DC/DC converters requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for STPS30120CT 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 STPS30120CT belongs to ST's high-voltage Schottky rectifier product line, engineered specifically for high-efficiency, high-frequency switch-mode power supplies where low forward voltage, controlled leakage, and thermal robustness are essential.

FAQ

What is the pin configuration of STPS30120CT?

The STPS30120CT has three terminals: Anode 1 (A1), Anode 2 (A2), and Common Cathode (K). In the TO-220AB package, A1 and A2 are the left and right leads respectively when viewing the front (marked side) with the tab down; K is the metal tab and center lead. This configuration supports center-tap transformer rectification without external parallel connections.

Is STPS30120CT suitable for surface-mount assembly?

No - STPS30120CT is exclusively offered in through-hole TO-220AB and TO-220AB narrow leads packages. It is not available in SMD variants like D²PAK or SO-8. Mounting requires PCB through-holes, mechanical screw fixation to a heatsink, and torque control (0.55 N·m recommended) to ensure reliable thermal contact and electrical integrity.

How does the avalanche rating impact reliability in SMPS designs?

The 480 W avalanche rating (at 10 µs, Tj = 125 °C) certifies that STPS30120CT can safely absorb inductive energy from transformer leakage inductance or layout parasitics without failure. This eliminates the need for external snubbers in many flyback and forward converter designs, reducing component count and improving long-term reliability under repeated transient stress.

Can STPS30120CT replace older STPS30L120CT parts?

Yes - STPS30120CT supersedes STPS30L120CT with identical pinout, package, and electrical specifications, but adds enhanced avalanche testing and updated ECOPACK®2 compliance. No layout or thermal redesign is required; the newer part offers improved process consistency and broader environmental certification without functional compromise.