STMicroelectronics STPST3H100UF

Overview

STPST3H100UF from STMicroelectronics is a 3 A, 100 V Schottky trench rectifier in SMB Flat package, optimized for high-frequency SMPS with low conduction and switching losses. It features 0.600 V typical forward voltage at 3 A/125 °C, 175 °C max junction temperature, and avalanche-rated 5 A single-pulse capability - deployed in telecom auxiliary supplies and LED lighting flyback converters.

For engineers reviewing the STPST3H100UF datasheet, STPST3H100UF pinout, STPST3H100UF application, or STPST3H100UF equivalent, key selection criteria include VF/IR trade-off at 125 °C, thermal resistance (Rth(j-l) = 10 °C/W), avalanche ruggedness, flat-package thermal performance, and ECOPACK2 compliance for industrial power designs.

Technical Context

This device uses ST's proprietary trench Schottky technology to achieve superior forward voltage versus reverse leakage balance across temperature - VF remains ≤0.650 V at 3 A/125 °C while IR stays ≤3.0 mA at 70 V/125 °C. Its low Qrr and soft recovery reduce EMI and switching loss in 100–500 kHz flyback and DC/DC topologies.

The SMB Flat package delivers 10 °C/W junction-to-lead thermal resistance and supports high-density PCB layouts without heatsinks up to 3 A continuous current at Tl = 140 °C. Avalanche testing per IAS = 5 A (L = 300 µH, VDD = 15 V) confirms robust unclamped inductive switching capability.

Key Specifications

Pinout & Package

SMB Flat package: surface-mount, 2-terminal, gull-wing leads, 5.10–5.60 mm body width, 3.30–3.95 mm length, 0.90–1.10 mm height. Optimized for automated placement and reflow-compatible thermal pad layout.

Key Features

Applications

Equivalent & Alternatives

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

Compared with NSS10300U1T6G and VSKT3100L-M3/45, STPST3H100UF delivers superior thermal robustness (10 °C/W), guaranteed avalanche survival (5 A), and lower VF drift over temperature - making it optimal for thermally constrained, high-reliability auxiliary and flyback outputs.

Availability

STPST3H100UF is available at Aetrix Electronics and suitable for telecom auxiliary supplies, LED lighting flyback converters, server standby rails, and smart metering power conversion requiring stable component supply and long-term industrial availability.

Supply support for STPST3H100UF 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, designing and manufacturing silicon solutions for automotive, industrial, power, and digital consumer markets.

The STPST3H100UF belongs to ST's trench Schottky rectifier product line - engineered specifically for high-efficiency, high-frequency switched-mode power supplies where low VF, low Qrr, and thermal resilience are critical.

FAQ

What is the maximum allowable PCB copper area for optimal thermal performance of STPST3H100UF?

For SMB Flat mounting on FR4 with 70 µm copper, Rth(j-a) drops to ~25 °C/W with 100 cm² total copper (50 cm² per lead). Minimum recommended pad area per lead is 3.44 mm × 1.20 mm (per Figure 14), and doubling copper thickness to 105 µm further reduces thermal resistance by ~15%.

Does STPST3H100UF require a snubber circuit in flyback applications?

No snubber is required for typical 100–300 kHz flyback operation due to its soft reverse recovery and low Qrr. However, a 100 pF/100 Ω RC network is recommended across anode–cathode if ringing exceeds 200 MHz or peak reverse voltage exceeds 90 V during MOSFET turn-on transients.

How does STPST3H100UF compare to standard Schottky diodes in terms of reverse leakage at 125 °C?

At 70 V and 125 °C, STPST3H100UF exhibits IR ≤ 0.45 mA (typ. 0.8 mA), significantly lower than conventional Schottkys (often >2 mA under same conditions), due to trench isolation - improving light-load efficiency and reducing standby power in auxiliary supplies.

Is STPST3H100UF compatible with lead-free reflow profiles per JEDEC J-STD-020?

Yes - STPST3H100UF's SMB Flat package is qualified for peak reflow temperatures up to 260 °C (per JEDEC J-STD-020D), with MSL level 1 rating. The device withstands three reflow cycles without degradation to VF, IR, or avalanche performance.