STMicroelectronics STPS40170CW

Overview

STPS40170CW from STMicroelectronics is a dual-center-tab 170 V, 2 × 20 A average forward current Schottky rectifier in TO-247 package, optimized for high-frequency SMPS and telecom power supplies with low VF (0.69 V typ. at 125 °C, 20 A) and high Tj (175 °C). It delivers low thermal resistance (Rth(j-c) = 0.85 °C/W total), avalanche-rated operation (1015 W peak), and ECOPACK®2 compliance.

For engineers reviewing the STPS40170CW datasheet, STPS40170CW pinout, STPS40170CW application, or STPS40170CW equivalent, key selection criteria include dual-diode thermal coupling behavior, junction-to-case thermal path validation, reverse leakage performance at 125 °C, and TO-247 mounting torque specification (0.8 N·m recommended).

Technical Context

This dual Schottky rectifier integrates two independent 170 V/20 A diodes sharing a common cathode tab and thermally coupled die structure - enabling balanced conduction in interleaved or parallel DC/DC phases. Its low forward voltage drop and fast recovery (no minority-carrier storage) minimize switching losses in hard-switched topologies above 100 kHz.

The device operates up to 175 °C junction temperature with validated avalanche capability (10 µs pulses, 1015 W), and exhibits low Rth(j-c) of 1.20 °C/W per diode and 0.85 °C/W total - critical for high-power density designs where thermal coupling between diodes affects derating curves.

Key Specifications

Pinout & Package

TO-247 package with three terminals: Cathode (center tab, electrically common to both diodes), Anode 1 (lead 1), and Anode 2 (lead 2). The metal tab is cathode-connected and serves as primary thermal path; mounting torque must be 0.8 N·m (max 1.0 N·m) for optimal Rth(j-c) performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with VS-40CPH017 and MBR40170CT, STPS40170CW offers superior thermal coupling (0.85 °C/W total), certified avalanche capability, and TO-247 mechanical robustness - making it the preferred choice for high-reliability telecom and industrial power stages where thermal co-location and transient immunity are design-critical.

Availability

STPS40170CW is available at Aetrix Electronics and suitable for telecom AC-DC front-ends, industrial DC/DC converters, and redundant power supply units requiring stable component supply, long-lifecycle support, and traceable sourcing.

Supply support for STPS40170CW 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.

The STPS series targets high-efficiency power conversion, with STPS40170CW specifically engineered for high-current, high-reliability Schottky rectification in telecom and industrial SMPS where thermal coupling, avalanche ruggedness, and low VF consistency are essential.

FAQ

What is the maximum continuous current per diode at 100 °C case temperature?

At Tc = 100 °C, the STPS40170CW supports 20 A average forward current per diode - identical to its rated IF(AV) at Tc = 150 °C - because its thermal derating curve remains flat up to 150 °C due to low Rth(j-c). This is confirmed in Figure 2 of DS4412, showing 20 A maintained from 25 °C to 150 °C ambient-equivalent case temperature.

Can the cathode tab be electrically isolated from the heatsink?

Yes, the cathode tab must be electrically isolated from the heatsink using an insulating washer and shoulder washer kit (e.g., Bergquist Sil-Pad 2000), as the tab is directly connected to both diode cathodes. Failure to isolate risks shorting the output bus to chassis ground in floating-output topologies like LLC resonant converters.

Is the STPS40170CW suitable for synchronous rectification replacement?

No - it is a passive Schottky rectifier, not a synchronous rectifier IC or MOSFET driver. While it replaces MOSFETs in low-voltage, high-current secondary-side rectification due to its low VF, it cannot be actively controlled or gated. Synchronous rectification requires gate-drive signals and timing control absent in this device.

Does the device require derating when both diodes conduct simultaneously?

Yes - simultaneous conduction increases total power dissipation and raises junction temperature nonlinearly due to thermal coupling. Table 2 specifies that ΔTj(diode 1) = P(diode1) × 1.20 + P(diode 2) × 0.50, meaning 1 W in Diode 2 adds 0.5 °C to Diode 1's junction rise. Full 40 A combined load requires case temperature derating to ≤130 °C to stay within 175 °C Tj limit.