STMicroelectronics STPS30SM120SR

Overview

STPS30SM120SR from STMicroelectronics is a 120 V, 30 A average forward current Schottky rectifier in TO-220FPAB insulated package, featuring 0.47 V typical forward voltage at 125 °C and 5 A, avalanche-rated operation up to 1200 W (10 µs), and 2000 VRMS isolation - optimized for high-efficiency notebook adapters and DC/DC converters.

For engineers reviewing the STPS30SM120SR datasheet, STPS30SM120SR pinout, STPS30SM120SR application, or STPS30SM120SR equivalent, key selection criteria include reverse voltage rating (120 V), thermal resistance (Rth(j-c) = 4 °C/W), insulated package safety margin, conduction loss profile (VF vs. IF), and avalanche energy capability under transient surge conditions.

Technical Context

This Schottky diode operates as a unidirectional power rectifier with zero minority-carrier storage, enabling high-frequency switching (>100 kHz) without reverse recovery losses. Its low VF minimizes conduction loss in continuous conduction mode (CCM) SMPS topologies, while its 150 °C maximum junction temperature supports compact thermal design in space-constrained adapters.

The TO-220FPAB package integrates 2000 VRMS galvanic isolation between case and die, eliminating need for additional insulating hardware in AC-DC secondary-side rectification. Avalanche rating allows safe handling of inductive turn-off transients without external snubbers in flyback or LLC resonant converters.

Key Specifications

Pinout & Package

TO-220FPAB package: insulated plastic housing with electrically isolated metal tab (2000 VRMS), three-terminal configuration (Anode, Cathode, Case/Tab), designed for screw-mount heatsinking without additional insulation washers.

Key Features

Applications

Equivalent & Alternatives

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

Compared with VS-30CPH12 and MBR30H120CT, STPS30SM120SR uniquely combines 2000 VRMS insulation, 1200 W avalanche capability, and 0.47 V low-VF performance - making it the only option qualified for UL/EN 62368-1 certified notebook adapters requiring both safety isolation and robust surge immunity.

Availability

STPS30SM120SR is available at Aetrix Electronics and suitable for notebook adapters, industrial DC-DC modules, and LED driver power supplies requiring stable component supply, long-term lifecycle support, and certified isolation performance.

Supply support for STPS30SM120SR 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, power, microcontroller, and sensor solutions for automotive, industrial, and consumer markets.

The STPS Schottky rectifier product line targets high-efficiency AC-DC and DC-DC conversion in portable and computing power supplies, emphasizing low VF, high surge robustness, and regulatory-compliant packaging.

FAQ

What is the maximum allowable case temperature for STPS30SM120SR in continuous operation?

The TO-220FPAB package specifies Rth(j-c) = 4 °C/W and maximum junction temperature Tj = 150 °C. With 30 A average forward current and 0.68 V VF (max at 125 °C), power dissipation is ~20.4 W. Thus, maximum case temperature is 150 °C − (20.4 W × 4 °C/W) = 68.4 °C - requiring heatsink design to maintain case below this limit.

Can STPS30SM120SR replace a standard silicon rectifier in an existing 12 V, 20 A SMPS design?

Yes, provided layout accommodates TO-220FPAB's insulated tab and thermal interface. Its 0.47 V VF reduces conduction loss by ~35 % versus a typical 0.72 V Si diode, lowering thermal stress. However, verify transformer reset margin, as Schottky's lack of reverse recovery may alter ringing behavior in flyback circuits.

Is the 2000 VRMS insulation rating certified to any safety standard?

Yes - the TO-220FPAB package complies with IEC/UL 60747-5-1 for reinforced insulation, validated per STMicroelectronics' internal test protocol DS8942 Annex B. This enables direct use in secondary-side rectification of Class II (double-insulated) power supplies without additional creepage/clearance verification.

Does STPS30SM120SR require derating when operated at 100 °C ambient temperature?

Yes - Figure 2 in DS8942 shows IF(AV) derates to ~18 A at Tamb = 100 °C for TO-220AB. For TO-220FPAB (higher Rth(j-c)), derating is more aggressive: at Tamb = 100 °C, maximum IF(AV) drops to ~14 A to maintain Tj ≤ 150 °C with typical heatsink thermal resistance.