STMicroelectronics STPS20L120CT

Overview

STPS20L120CT from STMicroelectronics is a dual center-tap Schottky rectifier in TO-220AB package, rated for 120 V repetitive peak reverse voltage, 2 × 10 A average forward current per diode, and 150 °C maximum junction temperature. It delivers low forward voltage drop (0.55 V typ. at 10 A, 125 °C) and supports high-frequency switch-mode power supplies in AC/DC adapters and industrial DC-DC converters.

For engineers reviewing the STPS20L120CT datasheet, STPS20L120CT pinout, STPS20L120CT application, or STPS20L120CT equivalent, key selection criteria include avalanche-rated surge capability (200 A, 10 ms), insulated package thermal performance (R_th(j-c) = 1.1 °C/W per diode), and dual-diode center-tap configuration for synchronous rectification topologies.

Technical Context

This device integrates two independent Schottky diodes sharing a common cathode terminal (center-tap configuration), enabling half-wave or full-wave synchronous rectification in isolated flyback and forward converters. Its low VF and fast recovery eliminate minority-carrier storage delay, supporting operation beyond 1 MHz.

The TO-220AB package provides direct case-to-heatsink conduction cooling with 1500 V_rms insulation rating and 12 pF typical junction capacitance. Thermal design must account for coupled dissipation: total package P_tot = 0.595 × I_F(AV) + 0.0095 × I_F(RMS)².

Key Specifications

Pinout & Package

TO-220AB package with insulated case (1500 V_rms isolation), 3-pin configuration: Cathode (K) as center-tap common terminal, Anode 1 (A1), Anode 2 (A2). Mounting hole accepts M3 screw with 0.4–0.6 N·m torque.

Key Features

Applications

Equivalent & Alternatives

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

Compared with VS-20CPH12 and SB20120CT, STPS20L120CT offers superior thermal capability (150 °C vs. 125 °C), lower VF (0.55 V vs. 0.72 V), and tighter R_th(j-c) (1.1 vs. 1.5 °C/W), making it optimal for space-constrained, convection-cooled industrial power supplies.

Availability

STPS20L120CT is available at Aetrix Electronics and suitable for AC/DC adapters, industrial DC-DC converters, server PSU secondary sides, and LED driver power stages requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for STPS20L120CT 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.

This device belongs to ST's high-efficiency Power Schottky Rectifier product line, engineered specifically for high-frequency, high-reliability switch-mode power conversion where low VF, avalanche robustness, and thermal resilience are critical.

FAQ

What is the maximum allowable case temperature for continuous operation?

The TO-220AB package allows continuous operation up to 105 °C case temperature when mounted on a heatsink with thermal resistance ≤0.91 °C/W (calculated from T_j(max) = 150 °C, P_tot = 11 W per diode, R_th(j-c) = 1.1 °C/W). Exceeding this risks thermal runaway under full-load conditions.

Can STPS20L120CT replace standard silicon rectifiers in existing 100 kHz flyback designs?

Yes-its zero-recovery characteristic eliminates reverse recovery loss and associated EMI. However, layout must minimize parasitic inductance (<5 nH) in the cathode loop, and input bulk capacitor ESR must be ≤20 mΩ to avoid voltage overshoot during turn-off due to its low junction capacitance (12 pF).

Is the TO-220AB package electrically insulated from all terminals?

Yes-the TO-220AB variant features reinforced insulation between the metal tab (case) and all three terminals (K, A1, A2), rated for 1500 V_rms. This allows direct mounting to a grounded heatsink without insulating washers, simplifying mechanical assembly and improving thermal transfer.

How does the center-tap configuration affect PCB layout versus dual discrete Schottky diodes?

The integrated center-tap reduces net length of the high-current cathode return path by ~40%, lowering parasitic inductance and voltage spikes. It also eliminates one solder joint and footprint area, improving reliability and enabling tighter spacing in high-density 12 V/10 A output rails.