STMicroelectronics EVLSRK1000-DP

Overview

EVLSRK1000-DP from STMicroelectronics is a demonstration board for the SRK1000B adaptive synchronous rectification controller, designed to replace secondary-side diodes in flyback converters. It integrates the STF80N10F7 100 V / 10 mΩ N-channel MOSFET in TO-220FP package, supports up to 500 kHz switching, operates from 3.5 V to 32 V VCC, and handles up to 90 V DVS - validated for quasi-resonant (QR) operation with optional fixed-frequency (FF) configuration.

For engineers reviewing the EVLSRK1000-DP datasheet, EVLSRK1000-DP pinout, EVLSRK1000-DP application, or EVLSRK1000-DP equivalent, this board enables rapid evaluation of adaptive turn-off SR control in high-efficiency AC/DC adapters, USB PD chargers, and industrial flyback power supplies where diode replacement with synchronous rectification improves efficiency by 2–4% at light-to-moderate loads.

Technical Context

The EVLSRK1000-DP implements ST's SRK1000B controller, which uses fixed turn-on timing and adaptive turn-off detection based on drain-voltage slope (dVDS/dt) to prevent cross-conduction in flyback secondaries. It drives an external N-channel MOSFET directly via integrated 1.2 A peak gate driver with internal bootstrap circuitry.

Board-level design includes factory-configured QR mode support, a 68 kΩ resistor on TON pin setting ~0.8 μs blanking time, and provision for FF mode via addition of a 100 pF capacitor at C4 - enabling evaluation across both QR and mixed DCM-CCM flyback topologies without hardware redesign.

Key Specifications

Availability

EVLSRK1000-DP is available at Aetrix Electronics and suitable for USB PD adapters, industrial AC/DC power supplies, and telecom offline converters requiring stable component supply, quick-turn evaluation, and documented SR implementation reference.

Supply support for EVLSRK1000-DP 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, delivering silicon solutions for automotive, industrial, power, and analog applications with emphasis on energy efficiency and system integration.

The SRK series targets high-efficiency secondary-side synchronous rectification in isolated DC/DC converters, specifically addressing thermal and efficiency bottlenecks in flyback-based power supplies below 100 W.

FAQ

What topology does the EVLSRK1000-DP support?

The EVLSRK1000-DP is configured for quasi-resonant (QR) flyback operation out-of-the-box, with documented hardware modification (adding 100 pF at C4) to enable fixed-frequency (FF) mixed DCM-CCM flyback evaluation. It does not support forward, LLC, or active clamp topologies.

Can I substitute a different MOSFET on the EVLSRK1000-DP board?

Yes - the board uses a standard TO-220FP footprint and provides gate drive compatible with N-channel MOSFETs rated ≥100 V and ≤15 nC total gate charge. Replacement requires verifying dVDS/dt sensitivity and adjusting R5 if blanking time must be modified for new device characteristics.

Does the EVLSRK1000-DP include isolation or primary-side control circuitry?

No - it is a secondary-side-only evaluation board. It contains only the SRK1000B controller, gate driver, STF80N10F7 MOSFET, and supporting passives. Primary-side controller, transformer, input rectification, and feedback circuitry must be provided externally.

Is the EVLSRK1000-DP RoHS-compliant and lead-free?

Yes - per STMicroelectronics DB3491 Rev 1 documentation, the EVLSRK1000B-TO (identical board variant) complies with EU RoHS Directive 2011/65/EU and uses lead-free solder and halogen-free PCB materials throughout.