STMicroelectronics STPS640CSFY

Overview

STPS640CSFY from STMicroelectronics is an AEC-Q101-qualified dual 3 A automotive Schottky rectifier in PSMC (TO-277A) package, rated for 40 V repetitive peak reverse voltage, 150 °C max junction temperature, and typ. 0.37 V forward voltage at 3 A and 125 °C - optimized for secondary rectification in DC/DC converters and freewheeling in engine control units.

For engineers reviewing the STPS640CSFY datasheet, STPS640CSFY pinout, STPS640CSFY application, or STPS640CSFY equivalent, key selection criteria include dual-diode thermal coupling, low VF stability across -40 to 150 °C, surge current capability up to 120 A, and ECOPACK2 compliance for automotive power systems requiring reverse polarity protection and high-reliability conduction efficiency.

Technical Context

This dual common-cathode Schottky rectifier integrates two independent 3 A diodes sharing a thermally coupled case, enabling balanced current sharing and synchronized thermal management in compact automotive power stages. Its VF remains stable across wide temperature range (25–125 °C), with leakage current tightly controlled up to 150 °C.

The device operates under strict automotive thermal constraints: Rth(j-c) = 1.5 °C/W enables efficient heat transfer to PCB copper pads, while its 120 A non-repetitive surge rating supports transient load dumps and inductive kickback suppression in ECU and DC/DC converter outputs.

Key Specifications

Pinout & Package

STPS640CSFY uses the PSMC (TO-277A) surface-mount package: single-row, 3-terminal, common-cathode configuration with exposed metal tab for thermal conduction. The package has no isolation; cathode is electrically connected to the tab.

Key Features

Applications

Equivalent & Alternatives

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

Compared with NSS40300DDWFT1G and VS-6CWQ04FNTR-M3, STPS640CSFY delivers superior thermal performance (1.5 °C/W), lowest VF at high temperature, and smallest footprint among AEC-Q101-qualified dual Schottkys - making it optimal for space- and thermal-constrained automotive power stages.

Availability

STPS640CSFY is available at Aetrix Electronics and suitable for engine control units, automotive DC/DC converters, and solenoid driver circuits requiring stable component supply, AEC-Q101 compliance, and long-term production continuity.

Supply support for STPS640CSFY 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 microcontrollers, power devices, sensors, and analog ICs for automotive, industrial, and consumer markets.

STPS640CSFY belongs to ST's automotive-qualified power Schottky rectifier product line, engineered specifically for high-efficiency, high-reliability secondary-side power conversion in harsh-temperature vehicle subsystems.

FAQ

What is the maximum continuous current per diode at 150 °C junction temperature?

At Tj = 150 °C, the STPS640CSFY supports 3 A average forward current per diode when mounted on a PCB with sufficient copper area to maintain Tc ≤ 140 °C. Derating is required above this case temperature; the datasheet curve shows IF(AV) drops to ~2.2 A at Tc = 150 °C per diode.

Is the cathode terminal electrically isolated from the thermal tab?

No. In the PSMC (TO-277A) package, the cathode (K) is directly connected to the exposed metal tab. This tab must be routed to system ground or the common output node and cannot be insulated - it serves both electrical and thermal functions simultaneously.

Can STPS640CSFY replace a single 6 A Schottky in a freewheeling application?

Yes, but only if the application requires dual-anode routing or thermal separation. As a dual 3 A device, its total device IF(AV) is 6 A, but each diode must carry ≤3 A continuously. It is not a drop-in replacement for monolithic 6 A parts unless layout and thermal design accommodate two independent anodes.

Does ST provide SPICE models or thermal simulation files for STPS640CSFY?

ST does not publish SPICE models for STPS640CSFY. However, thermal simulation guidance is provided in Application Note AN5088, including Zth(j-c) curves, Rth(j-a) vs. copper area data, and mounting recommendations for FR4 PCBs with 70 µm copper thickness.