STMicroelectronics STPS1L40A

Overview

STPS1L40A from STMicroelectronics is a 40 V, 1 A surface-mount Schottky rectifier in SMA package, featuring low forward voltage drop (0.37 V typ. at 1 A, 125 °C), avalanche rating, and ECOPACK2 compliance. It serves as a high-efficiency freewheeling or reverse polarity protection diode in TV and set-top box power supplies.

For engineers reviewing the STPS1L40A datasheet, STPS1L40A pinout, STPS1L40A application, or STPS1L40A equivalent, key selection criteria include its 175 °C max junction temperature, 0.37 V forward voltage at rated current and temperature, avalanche energy capability (65 W peak), thermal resistance (30 °C/W junction-to-lead), and compatibility with automated SMT assembly on FR4 PCBs.

Technical Context

This Schottky rectifier uses a single-chip planar structure optimized for high-frequency DC/DC conversion and low-loss freewheeling. Its low VF and negligible switching losses stem from zero minority-carrier storage and absence of reverse recovery charge.

Rated for repetitive peak reverse voltage of 40 V and average forward current of 1 A (at TL = 155 °C), it operates up to 175 °C junction temperature and supports surge currents up to 60 A (10 ms sinusoidal) in SMA package-enabling robustness in transient-prone power rails.

Key Specifications

Pinout & Package

STPS1L40A is housed in an SMA (DO-214AC) surface-mount package with cathode indicated by a band. The device has two terminals: anode and cathode, mounted on standard FR4 PCBs using reflow soldering per JEDEC J-STD-020.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SS14 and MBR140, STPS1L40A delivers superior thermal performance (30 °C/W vs. ≥35 °C/W), lower forward voltage (0.37 V vs. ≥0.5 V), and guaranteed avalanche ruggedness-making it optimal for compact, high-reliability 40 V power rails.

Availability

STPS1L40A is available at Aetrix Electronics and suitable for TV power supply output rectification, set-top box reverse polarity protection, and battery charger input isolation requiring stable component supply across industrial and consumer production programs.

Supply support for STPS1L40A 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.

STPS1L40A belongs to ST's high-efficiency Schottky rectifier product line, engineered specifically for low-voltage, high-frequency power conversion in space- and thermal-constrained consumer power supplies.

FAQ

What is the maximum allowable ambient temperature for STPS1L40A at 1 A DC load?

At 1 A average forward current and δ = 0.5 square wave, STPS1L40A in SMA package supports up to 125 °C ambient temperature when mounted on 4 cm² copper per lead (per Figure 2). Derating begins above this point; full 1 A rating requires lead temperature ≤155 °C.

Does STPS1L40A require a heatsink in typical SMT applications?

No external heatsink is required. With R_th(j-l) = 30 °C/W and P_D ≈ 0.37 W at 1 A/125 °C, junction temperature rise is ~11 °C above lead temperature. Standard 1–2 oz copper pads provide sufficient conduction cooling for most consumer power supply layouts.

Is STPS1L40A suitable for synchronous rectification replacement?

No. STPS1L40A is a passive Schottky rectifier-not a synchronous rectifier controller or MOSFET driver. It replaces conventional diodes in freewheeling or output rectification roles but cannot substitute for active gate-driven MOSFETs in synchronous topologies.

How does the avalanche rating of STPS1L40A improve system reliability?

The 65 W avalanche power rating (10 µs pulse, T_j = 125 °C) allows STPS1L40A to safely absorb inductive energy spikes-such as those from transformer leakage in flyback converters-without failure. This eliminates reliance on external snubbers and improves long-term field reliability in cost-sensitive consumer power supplies.