STMicroelectronics STTH310RL

Overview

STTH310RL from STMicroelectronics is a 1000 V, 3 A ultrafast recovery rectifier diode using planar technology, optimized for clamping, snubbing, and freewheeling in high-frequency switch-mode power supplies (SMPS), auxiliary power rails, and DC-DC converters. It delivers soft switching with 75 ns max reverse recovery time and 0.98 V typical forward voltage at 150 °C.

For engineers reviewing the STTH310RL datasheet, STTH310RL pinout, STTH310RL application, or STTH310RL equivalent, key selection criteria include its 1000 V repetitive peak reverse voltage, 55 A non-repetitive surge current rating, 175 °C maximum junction temperature, and DO-201AD package compatibility for high-reliability industrial power designs.

Technical Context

This ultrafast diode employs ST's planar high-voltage process to achieve low stored charge and controlled minority-carrier lifetime, enabling soft reverse recovery with minimal EMI generation. Its 75 ns trr (max) and 300 ns tfr support operation up to several hundred kHz in hard-switched topologies.

The device is rated for 175 °C junction temperature and exhibits stable VF across temperature-0.98 V (typ) at 150 °C and 3 A-making it suitable for thermally constrained auxiliary supplies and high-efficiency flyback snubbers where conduction loss minimization is critical.

Key Specifications

Pinout & Package

STTH310RL is supplied in the DO-201AD axial-leaded package, featuring a glass-passivated planar junction and UL 94 V0 epoxy body. The package supports manual or wave soldering and provides robust mechanical mounting for high-vibration environments.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STTH3L06 and UF3007, STTH310RL uniquely balances 1000 V ruggedness, 75 ns soft recovery, and 0.98 V VF at 150 °C-making it optimal for thermally demanding, high-voltage auxiliary supplies where both efficiency and reliability are critical.

Availability

STTH310RL is available at Aetrix Electronics and suitable for industrial PLC power rails, AC-DC adapter auxiliary supplies, and flyback converter freewheeling applications requiring stable component supply and long-term manufacturability.

Supply support for STTH310RL 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, power, microcontroller, and sensor solutions for automotive, industrial, and consumer markets.

STTH310RL belongs to ST's ultrafast high-voltage rectifier product line, engineered specifically for high-frequency power conversion topologies where low recovery loss, soft switching, and thermal resilience are mandatory.

FAQ

What is the maximum junction temperature and how does it affect PCB layout?

The STTH310RL has a maximum junction temperature of +175 °C. This allows operation without active cooling in sealed enclosures, but PCB layout must minimize thermal resistance: use ≥10 mm straight lead length per DO-201AD footprint, attach cathode/anode leads to ≥2 cm² copper pour per side, and avoid routing high-current traces near sensitive analog sections to prevent thermal coupling.

Is STTH310RL compatible with lead-free reflow processes?

Yes-STTH310RL is qualified for lead-free wave and reflow soldering per JEDEC J-STD-020. Its DO-201AD package withstands peak temperatures up to 260 °C for 10 seconds. Preheat ramp rate should not exceed 3 °C/s, and board-level thermal mass must be balanced to avoid localized overheating of the epoxy body.

How does the 75 ns reverse recovery time impact EMI in a 250 kHz flyback design?

At 250 kHz, the 75 ns trr ensures reverse recovery completes well within one switching cycle (4 µs), limiting di/dt-induced voltage spikes to <15 V overshoot in typical 100 nH stray inductance layouts. This eliminates need for external RC snubbers and reduces conducted EMI above 30 MHz by 8–10 dB compared to standard fast recovery diodes.

Can STTH310RL replace STTH306 in an existing 600 V design?

Yes-STTH310RL is a direct drop-in replacement for STTH306 in DO-201AD footprints, offering identical pinout, thermal resistance, and average current rating. Its higher 1000 V VRRM adds safety margin, while slightly higher VF at room temperature is offset by superior 150 °C performance, improving long-term reliability in thermally stressed applications.