STMicroelectronics STPS1170AF

Overview

STPS1170AF from STMicroelectronics is a 170 V, 1 A surface-mount Schottky rectifier in SMA Flat package, optimized for high-frequency switching applications with negligible switching losses, low forward voltage (0.62 V typ. at 125 °C), and avalanche-rated ruggedness. It serves as a freewheeling or polarity protection diode in compact DC/DC converters, LED lighting drivers, and notebook adapters.

For engineers reviewing the STPS1170AF datasheet, STPS1170AF pinout, STPS1170AF application, or STPS1170AF equivalent, key selection criteria include its 175 °C max junction temperature, 20 °C/W junction-to-lead thermal resistance, low leakage (<1.5 µA at 25 °C), and ECOPACK2-compliant lead-free packaging for space-constrained, thermally demanding power stages.

Technical Context

The STPS1170AF employs a planar Schottky barrier structure enabling near-zero reverse recovery charge and minimal switching losses-critical for >100 kHz DC/DC topologies. Its 170 V repetitive peak reverse voltage and avalanche rating support robust operation under transient overvoltage conditions without external clamping.

Thermal performance is defined by R_th(j-l) = 20 °C/W and T_j(max) = 175 °C, allowing sustained 1 A average forward current at ambient temperatures up to 125 °C when mounted on FR4 PCBs with ≥1.52 mm² copper per lead. The device operates with VF = 0.62 V (typ.) at IF = 1 A and Tj = 125 °C, directly reducing conduction loss in low-voltage output stages.

Key Specifications

Pinout & Package

STPS1170AF is housed in an SMA Flat surface-mount package (JEDEC DO-214AC), featuring two terminals: anode and cathode. The cathode is marked by a band on the package body. Mounting requires a recommended footprint of 3.12 × 5.52 mm with 1.20 mm pad width per lead.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SS17-E3/5AT and MBR1100F, STPS1170AF uniquely combines 170 V rating, 0.62 V VF at elevated temperature, and certified avalanche capability-making it the sole choice for thermally constrained, high-reliability 48 V-class DC/DC and LED drivers requiring no derating.

Availability

STPS1170AF is available at Aetrix Electronics and suitable for LED lighting drivers, battery charger output stages, and DC/DC converter freewheeling applications requiring stable component supply, long-term lifecycle assurance, and ECOPACK2 environmental compliance.

Supply support for STPS1170AF 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 automotive, industrial, and consumer markets.

The STPS1170 series belongs to ST's high-efficiency Schottky rectifier product line, engineered specifically for high-frequency, low-loss power conversion in space- and thermal-constrained applications such as LED drivers and portable adapters.

FAQ

What is the maximum allowable PCB copper area for optimal thermal performance of STPS1170AF?

For optimal thermal performance, ST recommends ≥1.52 cm² of 35 µm-thick copper per lead on FR4 PCBs. This achieves R_th(j-a) ≈ 45 °C/W, enabling full 1 A I_F(AV) at 75 °C ambient. Larger copper areas further reduce thermal resistance but yield diminishing returns beyond 3 cm² per lead.

Is STPS1170AF suitable for use in synchronous rectification circuits?

STPS1170AF is a passive Schottky rectifier-not a synchronous rectifier IC-and cannot replace actively controlled MOSFETs in synchronous topologies. However, it serves as a high-efficiency alternative to standard diodes in non-synchronous flyback or buck freewheeling paths where gate drive complexity must be avoided.

Does STPS1170AF require a heatsink in typical 1 A applications?

No heatsink is required for STPS1170AF in typical 1 A applications when mounted on a standard FR4 PCB with ≥1.52 cm² copper per lead. Its R_th(j-l) = 20 °C/W and low VF enable self-cooling via PCB conduction-verified up to 125 °C ambient in notebook adapter reference designs.

How does the avalanche rating of STPS1170AF improve system reliability?

The STPS1170AF's 110 W repetitive avalanche rating (t_p = 10 µs) allows it to safely absorb inductive energy spikes-such as transformer leakage in flyback converters-without failure. This eliminates reliance on external snubbers or TVS diodes, reducing part count and improving long-term field reliability in unregulated input environments.