STMicroelectronics STTH15S12W

Overview

STTH15S12 from STMicroelectronics is an ultrafast high-voltage silicon rectifier diode using Turbo 2 technology, rated for 1200 V repetitive peak reverse voltage and 15 A average forward current, with 27 ns typical reverse recovery time and 1.9 V typical forward voltage at 150 °C - optimized as a boost diode in uninterruptible power supply (UPS) systems.

For engineers reviewing the STTH15S12 datasheet, STTH15S12 pinout, STTH15S12 application, or STTH15S12 equivalent, key selection criteria include reverse recovery time, thermal resistance, softness factor, junction temperature rating, and TO-220AC/DO-247 package compatibility for high-efficiency switching power conversion.

Technical Context

The STTH15S12 employs ST's Turbo 2 process to achieve ultrafast recovery (27 ns typ.) with soft reverse recovery (S ≥ 2), minimizing voltage overshoot and EMI in hard-switched PFC and boost stages. Its low R_th(j-c) of 1.4 °C/W enables high-power operation up to 175 °C junction temperature.

Designed for high-frequency, high-voltage rectification, it delivers low conduction loss (P = 1.9 × I_F(AV) + 0.0533 × I_F(RMS)²) and stable reverse leakage (<400 µA at 150 °C), supporting reliable operation in industrial UPS and solar inverters where thermal cycling and surge robustness are critical.

Key Specifications

Pinout & Package

STTH15S12W is supplied in DO-247 package: isolated metal tab (cathode), single lead (anode), designed for through-hole mounting with mechanical stability and enhanced thermal dissipation via case-to-heatsink conduction. Mounting torque: 0.4–0.6 N·m.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultrafast high-voltage rectifier applications.

Compared with STTH16R06D and IXYS MUR1512CT, STTH15S12W offers superior 27 ns recovery speed, documented softness (S ≥ 2), and DO-247 thermal performance - making it optimal for high-density, high-frequency UPS and solar boost stages where EMI control and thermal efficiency are prioritized.

Availability

STTH15S12W is available at Aetrix Electronics and suitable for uninterruptible power supply (UPS), solar photovoltaic inverters, industrial motor drives, and EV onboard chargers requiring stable component supply across multi-year production cycles.

Supply support for STTH15S12W 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 industrial, automotive, and consumer markets.

The STTH series belongs to ST's high-voltage power diode product line, engineered specifically for ultrafast, low-loss rectification in high-efficiency switched-mode power supplies and renewable energy systems.

FAQ

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

The STTH15S12W has a maximum junction temperature of 175 °C. This allows operation in high-ambient environments such as enclosed UPS cabinets or under-hood automotive applications. With R_th(j-c) = 1.4 °C/W, a 35 K temperature rise occurs at 15 A average current, so heatsink selection must maintain case temperature ≤140 °C for full-rated operation.

Is STTH15S12W pin-compatible with other TO-220AC diodes?

No - STTH15S12W uses the DO-247 package, not TO-220AC. The DO-247 has a single anode lead and isolated cathode tab, differing mechanically and thermally from TO-220AC's three-lead configuration. Direct replacement requires board layout revision and thermal interface revalidation.

How does the softness factor affect EMI in boost converter designs?

A softness factor ≥2 ensures monotonic decay of reverse recovery current, eliminating current zero-crossing oscillation. This reduces high-frequency spectral content in switching node waveforms, lowering conducted EMI and relaxing requirements on input EMI filters and snubber networks in 50–100 kHz PFC stages.

Can STTH15S12W be used in place of SiC Schottky diodes?

It can replace SiC diodes in cost-sensitive 1200 V applications where switching frequency is ≤100 kHz and moderate efficiency gain is acceptable. However, it lacks SiC's near-zero Q_RR and temperature-independent V_F; thus, it is unsuitable for >150 kHz or ultra-high-efficiency designs where SiC's advantages are decisive.