STMicroelectronics STPS2L40UF

Overview

STPS2L40UF from STMicroelectronics is a 40 V, 2 A low-drop Schottky rectifier in SMB Flat surface-mount package, optimized for high-frequency DC/DC converters and AC/DC adapters. It delivers typ. 0.31 V forward voltage at 2 A and 125 °C, with 150 °C max junction temperature and avalanche-rated ruggedness for telecom and TV power supplies.

For engineers reviewing the STPS2L40UF datasheet, STPS2L40UF pinout, STPS2L40UF application, or STPS2L40UF equivalent, this page provides verified thermal resistance (R_th(j-l) = 10 °C/W), reverse leakage (20 mA @ 100 °C), conduction loss equation (P = 0.22×I_F(AV) + 0.06×I_F(RMS)²), and ECOPACK2 compliance details critical for board-level thermal design and RoHS-compliant production.

Technical Context

This Schottky rectifier uses a single-chip planar structure with metal–semiconductor junction to eliminate minority-carrier storage delay, enabling negligible switching losses in >100 kHz SMPS topologies. Its low R_th(j-l) of 10 °C/W (SMB Flat) supports high-current operation without external heatsinking under δ = 0.5 square-wave conditions.

Designed for unidirectional free-wheeling and polarity protection, it features avalanche energy rating (158 W, t_p = 10 µs) and reverse leakage tightly specified up to 125 °C (max 80 mA), ensuring reliability in thermally constrained consumer power stages.

Key Specifications

Pinout & Package

SMB Flat package: ultra-thin surface-mount outline (3.30–3.95 mm × 5.10–5.60 mm × 0.90–1.10 mm height), lead-free, UL94 V0 epoxy, cathode marked by band. Optimized for automated placement and reflow with 0.75–1.50 mm lead length.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SB240-E3/54 and SS24HM3/84A, STPS2L40UF delivers the lowest thermal resistance and highest avalanche energy rating in SMB Flat form factor-enabling smaller PCB area, lower system temperature rise, and higher reliability in thermally dense consumer power supplies.

Availability

STPS2L40UF is available at Aetrix Electronics and suitable for telecom power supply, TV power supply, and battery charger designs requiring stable component supply, RoHS-compliant packaging, and high-volume tape-and-reel delivery.

Supply support for STPS2L40UF 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 automotive, industrial, and consumer markets.

STPS2L40UF belongs to ST's high-efficiency Schottky rectifier product line, engineered specifically for miniaturized, high-frequency switched-mode power supplies where low V_F, thermal efficiency, and avalanche ruggedness are critical.

FAQ

What is the maximum allowable ambient temperature for continuous 2 A operation in SMB Flat package?

At I_F(AV) = 2 A and duty cycle δ = 0.5, the SMB Flat package supports continuous operation up to 90 °C ambient temperature while maintaining T_j ≤ 150 °C, based on R_th(j-l) = 10 °C/W and typical PCB copper area (≥1 cm² per lead). Derating begins linearly above this point per Figure 3 in DS2146.

Does STPS2L40UF require a heatsink for 2 A operation?

No external heatsink is required. With R_th(j-l) = 10 °C/W and typical PCB copper thermal path, junction temperature rise is ≤20 °C above lead temperature at 2 A. A 1 cm² copper pour per lead achieves sufficient conduction cooling-verified in ST's AN5088 thermal mounting guidelines.

How does the avalanche rating impact circuit protection design?

The 158 W avalanche capability (t_p = 10 µs, T_j = 125 °C) allows STPS2L40UF to absorb inductive energy from unclamped flyback transformers or relay coils without failure. This eliminates need for parallel TVS diodes in cost-sensitive consumer power supplies, reducing BOM count and board space.

Is STPS2L40UF compatible with lead-free reflow profiles?

Yes. STPS2L40UF is qualified for lead-free reflow per JEDEC J-STD-020, with peak temperature tolerance up to 260 °C (10 s max). Its SMB Flat package uses matte tin plating and UL94 V0 epoxy, fully compliant with IPC/JEDEC standard profiles including ramp-to-peak rates ≤3 °C/s and time above 217 °C of 60–150 s.