STMicroelectronics STPS20L45CT

Overview

STPS20L45CT from STMicroelectronics is a dual-center-tap Schottky rectifier in TO-220AB package, rated for 45 V repetitive peak reverse voltage and 2 × 10 A average forward current per diode at TC = 135 °C. It delivers low forward voltage drop (typ. 0.44 V at 10 A, 125 °C), low switching losses, and avalanche capability-optimized for high-frequency DC/DC converters and SMPS secondary-side rectification in telecom and industrial power supplies.

For engineers reviewing the STPS20L45CT datasheet, STPS20L45CT pinout, STPS20L45CT application, or STPS20L45CT equivalent, key selection criteria include its insulated TO-220AB thermal performance (Rth(j-c) = 2.2 °C/W per diode), 2000 VRMS isolation rating, and dual-diode center-tap configuration enabling synchronous rectifier or full-wave bridge alternatives in compact 12–15 V output stages.

Technical Context

This device integrates two independent Schottky diodes sharing a common cathode terminal (center-tap configuration), enabling use in full-wave rectification without external interconnection. Its low VF and fast recovery eliminate minority-carrier storage delay, supporting operation beyond 500 kHz in resonant and LLC topologies.

The TO-220AB package provides direct metal tab thermal conduction with 2.2 °C/W junction-to-case resistance per diode and 2000 VRMS insulation-critical for isolated secondary-side designs where creepage/clearance and safety certification (e.g., IEC/EN 62368) are mandatory.

Key Specifications

Pinout & Package

TO-220AB package with insulated metal tab (plastic body), 3-pin configuration: Pin 1 = Anode 1, Pin 2 = Cathode (common center tap), Pin 3 = Anode 2. Tab is electrically isolated and thermally conductive.

Key Features

Applications

Equivalent & Alternatives

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

Compared with VS-20CTH04-M3/45 and MBR2045CT, STPS20L45CT uniquely combines certified 2000 VRMS insulation, avalanche ruggedness, and lowest VF at elevated temperature-making it the only choice for safety-critical, high-efficiency 12–24 V isolated DC/DC outputs requiring long-term reliability.

Availability

STPS20L45CT is available at Aetrix Electronics and suitable for telecom DC/DC converters, industrial SMPS secondary-side rectification, and medical isolated power supplies requiring stable component supply and long-lifecycle support.

Supply support for STPS20L45CT 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 microcontrollers, power devices, sensors, and analog ICs for automotive, industrial, and consumer markets.

The STPS series targets high-efficiency, high-reliability power conversion-specifically engineered for Schottky rectification in isolated switch-mode power supplies where low VF, thermal robustness, and safety insulation are critical.

FAQ

What is the maximum junction temperature and how does it affect thermal design?

The absolute maximum junction temperature is 150 °C. At this limit, the device sustains 10 A per diode only if case temperature is held at 135 °C via heatsink. Designers must use Rth(j-c) = 2.2 °C/W per diode and derate linearly above 25 °C ambient-e.g., at 70 °C ambient, max continuous current drops to ~7.3 A per diode with a 10 °C/W heatsink.

Is the TO-220AB tab electrically isolated, and what is the test voltage?

Yes-the TO-220AB package features an insulated metal tab rated for 2000 VRMS (sine wave, 1 minute) between tab and all pins. This is verified per IEC 60747-5-1 and allows direct mounting to grounded heatsinks without additional insulation, simplifying mechanical design and improving thermal transfer.

How does the center-tap configuration impact PCB layout versus discrete diodes?

The integrated center-tap eliminates two solder joints and interconnect traces required for discrete dual-diode solutions. This reduces parasitic inductance by up to 1.2 nH and saves ≥12 mm² board area-critical for high-frequency layouts where ringing and EMI must be minimized in <100 ns switching edges.

Does STPS20L45CT support parallel operation for higher current?

No-parallel operation is not recommended due to thermal coupling and mismatched VF drift with temperature. The device is rated for 20 A total (10 A per diode) only when both diodes share identical thermal paths and operate within ±5 °C junction temperature difference. For >20 A, use a single higher-current part like STPS30L45CG.