STMicroelectronics STTH806D

Overview

STTH806D from STMicroelectronics is a 600 V, 8 A ultrafast high-voltage rectifier diode in TO-220AC package, optimized for switching power supplies and industrial AC/DC converters. It delivers 35 ns reverse recovery time (trr), 1.1 V typical forward voltage at 150 °C, and 2.5 °C/W junction-to-case thermal resistance - enabling high-efficiency operation in compact, thermally constrained designs.

For engineers reviewing the STTH806D datasheet, STTH806D pinout, STTH806D application, or STTH806D equivalent, key selection criteria include its 600 V repetitive peak reverse voltage, ultrafast trr ≤ 35 ns at 25 °C, low IR ≤ 200 µA at 150 °C, TO-220AC mechanical footprint, and suitability for PFC and output rectification stages where conduction and switching loss minimization is critical.

Technical Context

The STTH806D employs ST's Turbo 2 silicon technology to achieve soft-recovery characteristics with low Qrr and controlled dV/dt immunity. Its dynamic performance is characterized under standardized test conditions: IF = 0.5 A, Irr = 0.25 A, VR = 30 V, Tj = 25 °C for trr measurement, and IF = 8 A, dIF/dt = −100 A/µs, VR = 400 V for IRM evaluation.

Thermally, it supports continuous operation up to 175 °C junction temperature with Rth(j–c) = 2.5 °C/W (TO-220AC), and exhibits stable VF drift across temperature - 1.10 V (typ) at 150 °C vs. 1.85 V (max) at 25 °C - ensuring predictable conduction loss behavior in wide-temperature industrial environments.

Key Specifications

Pinout & Package

STTH806D uses the standard TO-220AC package: single-diode configuration with isolated tab (electrically unconnected), 3-pin outline (anode, cathode, metal tab), and screw-mount compatible flange. The tab serves as the cathode terminal and provides primary thermal path.

Key Features

Applications

Availability

STTH806D is available at Aetrix Electronics and suitable for industrial motor drives, telecom rectifier modules, and renewable energy inverters requiring stable component supply, long-term lifecycle support, and traceable sourcing for production ramp-up.

Supply support for STTH806D 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.

The STTH series belongs to ST's high-voltage rectifier product line, engineered specifically for high-frequency switching applications demanding low trr, soft recovery, and robust thermal performance in industrial-grade power conversion systems.

FAQ

Is STTH806D pin-compatible with STTH806G?

No. STTH806D uses TO-220AC package with three leads (anode, cathode, unused), while STTH806G uses D2PAK surface-mount package with three terminals (anode, cathode, exposed pad). Mechanical mounting, thermal path, and PCB layout are incompatible; no direct board-level replacement is possible without redesign.

What is the maximum recommended heatsink thermal resistance for STTH806D at 8 A average current?

At IF(AV) = 8 A and Tc = 140 °C, junction temperature reaches 175 °C when Rth(j–a) ≤ 4.375 °C/W. Accounting for Rth(j–c) = 2.5 °C/W and typical interface resistance (~0.5 °C/W), maximum allowable Rth(c–a) is ~1.4 °C/W - requiring a forced-air or medium-sized extruded heatsink.

Does STTH806D require a snubber circuit in a 100 kHz flyback converter?

Not typically. Its soft recovery (S factor >1.0) and low Qrr (~35 nC) suppress voltage overshoot below 10% of VRRM under standard flyback conditions. Snubber use is only necessary if measured VDS spikes exceed 540 V or ringing persists after optimizing transformer leakage and layout.

Can STTH806D replace BYV26E in an existing design?

Yes, with validation. Both are 600 V, TO-220AC ultrafast diodes, but STTH806D offers lower VF (1.10 V vs. 1.35 V typ at 150 °C) and faster trr (35 ns vs. 50 ns max), reducing conduction and switching losses. Thermal design must be rechecked due to differing Rth(j–c) (2.5 vs. 3.0 °C/W).