STMicroelectronics EVLSRK1000-PF

Overview

EVLSRK1000-PF from STMicroelectronics is a demonstration board for the SRK1000 adaptive synchronous rectification controller, designed to replace secondary-side diodes in flyback converters. It integrates the SRK1000 IC and an FDMS86103L 100 V / 12 mΩ logic-level N-channel MOSFET in PowerFLAT 5×6 package, supports up to 500 kHz switching, and operates with VCC from 3.5 V to 32 V and DVS up to 90 V.

For engineers reviewing the EVLSRK1000-PF datasheet, EVLSRK1000-PF pinout, EVLSRK1000-PF application, or EVLSRK1000-PF equivalent, this board enables rapid evaluation of adaptive turn-off synchronous rectification in QR and fixed-frequency flyback topologies - especially where efficiency gains at light load and thermal reduction in high-current secondary-side rectification are critical.

Technical Context

The EVLSRK1000-PF implements ST's proprietary adaptive turn-off control scheme optimized for flyback secondary-side rectification, combining fixed turn-on timing with dynamic voltage-sensing-based turn-off to minimize reverse recovery losses. It supports both quasi-resonant (QR) operation (default configuration) and fixed-frequency (FF) mixed DCM-CCM modes via optional C4 capacitor addition.

It features internal gate-drive capable of sourcing/sinking >1 A peak current to drive the FDMS86103L MOSFET directly, with built-in blanking (0.8 µs via R5 = 68 kΩ on TON pin) to suppress noise-induced false triggering during transformer ringing.

Key Specifications

Availability

EVLSRK1000-PF is available at Aetrix Electronics and suitable for AC-DC adapter development, industrial flyback power supplies, and USB PD-compliant chargers requiring stable component supply and validated reference implementation.

Supply support for EVLSRK1000-PF 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 embedded 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 topologies across consumer, industrial, and computing power supplies.

FAQ

What topology does the EVLSRK1000-PF support?

The EVLSRK1000-PF is configured by default for quasi-resonant (QR) flyback operation, but supports fixed-frequency (FF) mixed DCM-CCM flyback by adding a 100 pF capacitor at C4. It is not intended for forward, LLC, or non-isolated topologies.

Can the board drive MOSFETs other than FDMS86103L?

Yes - the SRK1000 controller on the board can drive other logic-level N-channel MOSFETs, provided V_DS rating ≥90 V, gate threshold ≤2.5 V, and package thermal capability matches the PowerFLAT 5×6 footprint. The onboard layout and gate-drive strength are optimized for FDMS86103L, but external MOSFET substitution is feasible with layout review.

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

Yes - the EVLSRK1000-PF demonstration board complies with EU RoHS Directive 2011/65/EU and uses lead-free solder and components. ST's DB3427 data brief (Rev 1, Oct 2018) confirms full compliance, including exemption status for homogeneous materials per Annex III.

Does the board include input/output connectors or test points?

No - the EVLSRK1000-PF is a bare evaluation board without pre-mounted connectors. It provides solder pads for V_IN, V_OUT, GND, and transformer secondary connections, plus test points for V_DS, gate drive, and VCC signals as shown in Figure 1 of DB3427 Rev 1.