STMicroelectronics STTH806DTI

Overview

STTH806DTI from STMicroelectronics is a tandem 600 V hyperfast boost diode composed of two 300 V dice in series, designed for continuous-conduction-mode (CCM) power factor correction (PFC) stages and hard-switching SMPS topologies. It delivers 8 A average forward current, 13 ns typical reverse recovery time at 25 °C, 2.24 V max forward voltage at rated current, and 2500 VRMS insulation for MOSFET co-heatsinking.

For engineers reviewing the STTH806DTI datasheet, STTH806DTI pinout, STTH806DTI application, or STTH806DTI equivalent, key selection criteria include dIF/dt capability (up to 500 A/µs), soft recovery (S = 0.4), low Qrr (50 nC), thermal resistance (2.6 °C/W), and insulated TO-220AC package suitability for high-density PFC designs.

Technical Context

The STTH806DTI implements a series-connected dual-die architecture to achieve 600 V blocking while maintaining balanced static and dynamic characteristics across both internal 300 V junctions. Its hyperfast recovery (trr = 13 ns typ. at IF = 0.5 A) and low IRM (4 A typ. at Tj = 125 °C) minimize switching losses in high-frequency boost converters.

Designed for high di/dt operation, it supports dIF/dt up to 500 A/µs with controlled forward recovery voltage (VFP = 7 V max) and softness factor (S = 0.4), reducing EMI and MOSFET voltage overshoot during turn-off transitions in CCM PFC circuits.

Key Specifications

Pinout & Package

STTH806DTI uses an insulated TO-220AC package with electrically isolated tab (2500 VRMS isolation). The device has two anode terminals (A1, A2) and one common cathode (K), configured as a tandem diode with internal series connection of two 300 V dice.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STTH8R06DI and MUR860E, the STTH806DTI uniquely combines tandem die architecture, 2500 VRMS insulation, 13 ns trr, and soft recovery - making it the only option among the three qualified for high-density, high-efficiency, thermally integrated CCM PFC designs.

Availability

STTH806DTI is available at Aetrix Electronics and suitable for industrial AC-DC power supplies, server & telecom rectifier modules, and EV onboard charger input stages requiring stable component supply and long-lifecycle support.

Supply support for STTH806DTI 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, digital, and mixed-signal ICs, discrete devices, and MEMS sensors for industrial, automotive, and consumer markets.

The STTH "TURBOSWITCH H" product line targets high-efficiency, high-frequency power conversion - specifically engineered to replace standard FRDs in CCM PFC and resonant topologies where low Qrr, soft recovery, and thermal integration are critical.

FAQ

What is the maximum allowable dIF/dt for STTH806DTI?

The STTH806DTI is characterized up to 500 A/µs in datasheet Figure 4 (IRM vs. dIF/dt) and Figure 5 (trr vs. dIF/dt). At this rate, IRM remains ≤5.5 A and trr stays below 30 ns. Operation beyond 500 A/µs is not specified and may risk excessive voltage overshoot or localized heating at the die interface.

Can STTH806DTI be used in discontinuous conduction mode (DCM) PFC?

Yes - though optimized for CCM, the STTH806DTI functions reliably in DCM PFC. Its low Qrr and soft recovery still reduce MOSFET turn-on loss and EMI. However, its 8 A IF(AV) rating is over-specified for most DCM designs, where lower-current diodes (e.g., STTH3L06) are typically more cost-effective.

Does the insulated tab require thermal compound when mounted to a heatsink?

Yes - despite electrical isolation, the ceramic-insulated tab must be thermally coupled using standard thermal interface material (TIM) such as silicone-based grease or phase-change pads. The 2.6 °C/W Rth(j-c) rating assumes proper TIM application and recommended torque (0.4–0.6 Nm) on the mounting screw.

How does the tandem die structure affect voltage distribution under transient conditions?

The tandem structure ensures static and dynamic equilibrium between the two 300 V dice via matched process and layout - verified by ST's design validation. Under fast transients (dV/dt > 1000 V/µs), internal capacitance coupling maintains balanced voltage division, eliminating need for external balancing resistors even during surge events.