STMicroelectronics FERD20S100STS

Overview

FERD20S100STS from STMicroelectronics is a 100 V field-effect rectifier diode in TO-220AB package, delivering 20 A average forward current, 0.415 V max forward voltage at 20 A/125 °C, 110 µA max reverse leakage at 100 V/25 °C, and 1.3 °C/W junction-to-case thermal resistance. It replaces Schottky diodes in high-efficiency, thermally constrained AC/DC and DC/DC converters.

For engineers reviewing the FERD20S100STS datasheet, FERD20S100STS pinout, FERD20S100STS application, or FERD20S100STS equivalent, key selection criteria include VF/IR trade-off stability over temperature, thermal runaway mitigation, conduction loss modeling (P = 0.45×IF(AV) + 0.021×IF²(RMS)), and ECOPACK®2 compliance for industrial power supplies.

Technical Context

This device uses ST's proprietary field-effect rectifier process to decouple forward voltage (VF) and reverse leakage (IR) dependencies on junction temperature-reducing thermal runaway risk versus conventional Schottkys. Its VF remains stable across 25–125 °C and IR increases only modestly under 70 V bias at 125 °C.

Designed for confined-casing applications, it achieves best-in-class VF/IR balance per silicon area. The TO-220AB package enables direct heatsink mounting with 0.55 N·m recommended torque, supporting high-power density designs where thermal impedance (Rth(j-c) = 1.3 °C/W) and surge robustness (220 A IFSM) are critical.

Key Specifications

Pinout & Package

TO-220AB package with isolated tab (case), three leads: Anode (A), Cathode (K), and second Anode (A) - dual-anode configuration for parallel conduction path and reduced parasitic inductance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar field-effect rectifier diode applications.

Compared with STTH2010DI and VS-20EWH10, FERD20S100STS uniquely balances low VF and low IR across temperature-enabling higher power density without thermal runaway risk in sealed, convection-cooled systems.

Availability

FERD20S100STS is available at Aetrix Electronics and suitable for server power supplies, industrial DC/DC converters, medical imaging power modules, and EV onboard charger auxiliary stages requiring stable component supply and long-term lifecycle support.

Supply support for FERD20S100STS 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.

This device belongs to ST's Field-Effect Rectifier (FERD) product line, engineered specifically to replace Schottky diodes in high-efficiency, thermally demanding power conversion applications where VF/IR trade-off stability is critical.

FAQ

What is the thermal resistance from junction to ambient (Rth(j-a)) for FERD20S100STS?

Rth(j-a) is not specified as a fixed value-it depends on PCB copper area and heatsinking. For DPAK on FR4 with 90 cm² copper, typical Rth(j-a) is ~40 °C/W; for TO-220AB mounted on a 25 cm² heatsink, it drops to ~5.5 °C/W. Use Rth(j-c) = 1.3 °C/W plus your heatsink's Rth(c-s) to calculate total thermal resistance.

Can FERD20S100STS be used as a direct replacement for a 100 V Schottky diode?

Yes-its VF/IR profile is optimized to match or exceed Schottky performance while eliminating thermal runaway risk. At 125 °C, VF remains below 0.76 V and IR stays under 12 mA at 70 V, enabling drop-in use in existing layouts with identical footprint and pinout, provided mechanical mounting torque (0.55 N·m) and thermal interface are maintained.

Does FERD20S100STS require a heatsink in 20 A continuous operation?

Yes-continuous 20 A operation requires active or substantial passive heatsinking. With Rth(j-c) = 1.3 °C/W and max Tj = 175 °C, even at 25 °C ambient, junction temperature would reach ~150 °C without heatsink. A minimum 10 cm² aluminum heatsink (Rth(c-a) ≈ 15 °C/W) is recommended to keep Tj ≤ 125 °C at full load.

Is the TO-220AB package of FERD20S100STS electrically isolated?

No-the TO-220AB package has an electrically connected tab (anode). The metal tab is internally bonded to both anode leads and must be insulated from the heatsink using a mica or polymer washer unless circuit topology permits direct connection. Isolation voltage rating is not specified; assume no reinforced insulation between tab and leads.