STMicroelectronics STPS340SY

Overview

STPS340SY from STMicroelectronics is an AEC-Q101-qualified automotive Schottky rectifier in SMC package, rated for 3 A average forward current, 40 V repetitive peak reverse voltage, and 150 °C maximum junction temperature. It delivers low forward voltage drop (0.57 V max at 3 A, 125 °C), extremely fast switching, and avalanche capability-used in high-frequency DC-DC converters and polarity protection circuits in engine control units and body electronics.

For engineers reviewing the STPS340SY datasheet, STPS340SY pinout, STPS340SY application, or STPS340SY equivalent, key selection criteria include thermal resistance (20 °C/W junction-to-lead), surge current rating (75 A, 10 ms), low conduction losses, and automotive-grade reliability under transient load conditions.

Technical Context

This Schottky rectifier uses a single-chip silicon structure optimized for low VF and negligible reverse recovery charge, eliminating minority-carrier storage delay. Its design targets high-efficiency, high-frequency power conversion where thermal management and voltage headroom are critical.

Specified avalanche energy (1300 W, 1 µs pulse) and AEC-Q101 qualification confirm robustness against inductive switching transients in automotive 12 V/24 V systems. The SMC package provides lower thermal resistance than SMB, enabling higher continuous current handling at elevated ambient temperatures.

Key Specifications

Pinout & Package

The STPS340SY is housed in an SMC (DO-214AB) surface-mount package with cathode band marking. Lead material is matte tin-plated copper, compliant with RoHS and ECOPACK® environmental standards.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STPS340SY, the Vishay part trades thermal performance for smaller footprint and lacks automotive qualification, while the ON Semiconductor part matches qualification but omits avalanche capability-critical for unclamped inductive loads in EPS or starter systems.

Availability

STPS340SY is available at Aetrix Electronics and suitable for engine control units, infotainment power supplies, and body control modules requiring stable component supply across extended automotive product lifecycles.

Supply support for STPS340SY 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 analog, microcontroller, power, and sensor solutions for automotive, industrial, and consumer markets.

The STPS series targets automotive-grade power rectification, emphasizing low VF, high surge tolerance, and AEC-Q101 compliance for safety-critical 12 V/24 V subsystems.

FAQ

What is the maximum allowable case temperature for STPS340SY in continuous operation?

The device has no defined case temperature limit; instead, its safe operating area is governed by junction temperature. With Rth(j-l) = 20 °C/W and Pdiss ≤ 3.75 W (calculated from 3 A × 0.57 V), the lead temperature must remain ≤ 75 °C to keep Tj ≤ 150 °C. PCB copper area directly under leads determines actual thermal margin.

Does STPS340SY require a heatsink for 3 A DC operation?

No external heatsink is required if the PCB provides ≥ 4 cm² of 35 µm-thick copper per lead (per Figure 12). At 3 A and 125 °C junction temperature, thermal resistance to ambient drops to ~45 °C/W with this copper area-sufficient to maintain Tj < 150 °C at 70 °C ambient without airflow.

Is STPS340SY suitable for synchronous rectification topologies?

No-it is a passive Schottky diode, not a MOSFET-based synchronous rectifier. While it can replace active FETs in low-cost designs, it lacks gate drive interface and cannot achieve the sub-0.2 V conduction losses possible with controlled MOSFETs in high-efficiency SMPS.

How does the avalanche rating impact circuit design?

The 1300 W, 1 µs avalanche rating permits safe operation during unclamped inductive switching events-e.g., when used as a freewheeling diode across relay coils or motor windings. Designers must ensure pulse duration stays within Figure 5 derating curves and avoid repeated avalanching to prevent cumulative degradation.