STMicroelectronics STTH8R03D

Overview

STTH8R03D from STMicroelectronics is a 300 V, 8 A average forward current hyperfast recovery rectifier in TO-220AC package, featuring 30 ns maximum reverse recovery time (trr), 1.3 V maximum forward voltage at 125°C, and 2.5 °C/W junction-to-case thermal resistance-designed for high-frequency off-line SMPS and DC/DC converters where low switching loss and snubber size reduction are critical.

For engineers reviewing the STTH8R03D datasheet, STTH8R03D pinout, STTH8R03D application, or STTH8R03D equivalent, key selection criteria include trr ≤ 30 ns at dIF/dt = –50 A/µs, softness factor (S) = 0.4, peak reverse recovery current (IRM) ≤ 5.5 A at 125°C, and conduction loss modeling via P = 0.9 × IF(AV) + 0.05 × IF²(RMS).

Technical Context

This hyperfast rectifier employs optimized carrier lifetime control to achieve ultra-low trr while maintaining soft reverse recovery (S = 0.4), minimizing EMI and MOSFET turn-on stress in synchronous and quasi-resonant topologies. Its 175°C maximum junction temperature and 2.5 °C/W Rth(j-c) support high-power density designs with conductive heatsinking.

Unlike standard fast recovery diodes, STTH8R03D delivers <200 ns forward recovery time (tfr) and <3.5 V transient peak forward voltage (VFP) under 100 A/µs dIF/dt, enabling reliable operation in hard-switched PFC and LLC resonant converter secondary-side rectification.

Key Specifications

Pinout & Package

STTH8R03D uses the TO-220AC package: single-diode configuration with isolated tab (cathode-connected metal flange), 3-pin outline (A-K-A), and mechanical mounting via M3 screw (recommended torque: 0.55 N·m).

Key Features

Applications

Equivalent & Alternatives

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

Compared with STTH8R03G, STTH8R03D offers superior mechanical stability and thermal interface repeatability via TO-220AC mounting; versus MUR830, it delivers measurably lower trr, softer recovery, and tighter VF consistency across temperature-critical for high-density, high-reliability power supplies.

Availability

STTH8R03D is available at Aetrix Electronics and suitable for server power supplies, industrial DC/DC converters, LED driver bulk rectification, and automotive on-board charger auxiliary supplies requiring stable component supply, long-lifecycle availability, and traceable sourcing.

Supply support for STTH8R03D 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, specializing in power management, analog, microcontrollers, and automotive ICs.

The STTH "TURBOSWITCH R" family targets high-frequency power conversion, delivering hyperfast recovery and soft switching to replace GaAs diodes and reduce MOSFET stress in SMPS and DC/DC topologies.

FAQ

What is the recommended heatsink mounting method for STTH8R03D?

Mount STTH8R03D using a M3 screw with 0.55 N·m recommended torque onto an anodized or insulated heatsink. The metal tab is cathode-connected, so electrical isolation is mandatory unless the heatsink is referenced to cathode potential. Thermal interface material with ≤0.5 °C·in²/W resistance is advised for optimal Rth(j-c) performance.

How does STTH8R03D's softness factor affect circuit design?

The S factor of 0.4 indicates a controlled, gradual current decay during reverse recovery, reducing voltage spikes and EMI generation. This allows smaller snubbers, relaxed layout spacing, and lower gate-drive strength requirements for synchronous MOSFETs-particularly beneficial in high-dIF/dt PFC and resonant converters where hard recovery causes excessive ringing.

Can STTH8R03D replace Schottky diodes in 12 V output rails?

Yes-STTH8R03D is frequently used to replace 45 V Schottky diodes in 12 V outputs where junction temperature exceeds 125°C. Its 1.3 V VF at 125°C is competitive with high-temp Schottkys, and its 300 V rating provides margin against voltage transients that can rupture lower-VRRM Schottkys in noisy industrial environments.

What is the maximum allowable dIF/dt for reliable STTH8R03D operation?

STTH8R03D is characterized up to –200 A/µs (Fig. 4–6), with IRM ≤ 5.5 A and trr ≤ 30 ns at that rate. For sustained reliability, design dIF/dt ≤ 150 A/µs in continuous operation. Exceeding this requires validation of VFP (<3.5 V) and tfr (<200 ns) in the actual circuit, especially with high stray inductance in the diode loop.