STMicroelectronics STPS3170UF

Overview

STPS3170UF from STMicroelectronics is a 170 V, 3 A surface-mount Schottky rectifier in SMB Flat package, optimized for high-frequency switching applications including telecom power supplies and DC/DC converters. It delivers low forward voltage (0.63 V typ. at 125 °C, 3 A), negligible switching losses, avalanche rating, and operates up to 175 °C junction temperature.

For engineers reviewing the STPS3170UF datasheet, STPS3170UF pinout, STPS3170UF application, or STPS3170UF equivalent, key selection criteria include reverse voltage rating (170 V), average forward current (3 A), thermal resistance (15 °C/W junction-to-lead), low leakage (<4.0 µA at 25 °C), and ECOPACK2 compliance for environmental design requirements.

Technical Context

This Schottky rectifier uses a planar silicon structure with metal-semiconductor junction to eliminate minority-carrier storage delay, enabling zero reverse recovery time and minimal switching loss in high-frequency topologies. Its low VF and high Tj(max) support compact, thermally constrained designs in space-limited LED drivers and telecom SMPS.

The device is rated for repetitive avalanche energy (210 W at 10 µs, 125 °C) and exhibits stable reverse leakage across -40 °C to +175 °C ambient. Thermal performance is defined by Rth(j-l) = 15 °C/W (SMB Flat), with PCB copper area directly modulating Rth(j-a) per Figure 9.

Key Specifications

Pinout & Package

SMB Flat package: 2-terminal surface-mount diode with cathode band marking; dimensions 5.10–5.60 mm × 3.30–3.95 mm × 0.90–1.10 mm (L × W × H); UL94 V0 epoxy, lead-free finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SS317H and SB3170, STPS3170UF offers superior thermal robustness (175 °C Tj max), lowest VF at elevated temperature, and highest avalanche energy-critical for telecom and industrial power where reliability under transient stress is non-negotiable.

Availability

STPS3170UF is available at Aetrix Electronics and suitable for telecom power supplies, LED lighting drivers, and industrial DC/DC converters requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for STPS3170UF 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 microcontrollers, power devices, sensors, and analog ICs for industrial, automotive, and consumer markets.

The STPS3170 series belongs to ST's high-voltage Schottky rectifier product line, engineered specifically for efficiency-critical, high-frequency power conversion in space-constrained telecom and LED applications.

FAQ

What is the maximum allowable PCB copper area for optimal thermal performance of STPS3170UF?

Per Figure 9 in DS10645, Rth(j-a) drops from ~45 °C/W (no copper) to ~22 °C/W with 200 cm² total copper area under both leads on FR4. For most designs, ≥50 cm² per pad (100 cm² total) achieves Rth(j-a) ≤ 30 °C/W, enabling 3 A operation at 70 °C ambient without forced airflow.

Does STPS3170UF require derating at elevated ambient temperatures?

Yes. At Tamb = 100 °C, IF(AV) must be reduced to ~1.8 A (per Figure 2). Derating follows linear interpolation between 140 °C lead temperature limit and ambient; full 3 A rating applies only when TL ≤ 140 °C, achievable with ≥30 cm² copper per pad at Tamb ≤ 60 °C.

Can STPS3170UF replace a standard PN-junction rectifier in an existing 170 V design?

Yes, but only if reverse recovery noise and conduction loss are critical constraints. Unlike PN diodes, STPS3170UF has zero Qrr and lower VF, eliminating snubber networks and reducing heat sink size. However, its higher IR at 125 °C (0.73 mA) requires verification in high-temp reverse-bias hold applications.

Is STPS3170UF compatible with lead-free reflow profiles per JEDEC J-STD-020?

Yes. As an ECOPACK2-compliant device, STPS3170UF is qualified for peak reflow temperatures up to 260 °C (MSL3), with moisture sensitivity level 1. Recommended profile uses ramp rate ≤3 °C/s, peak 245–260 °C for ≤60 s, and cooling rate ≤6 °C/s.