STMicroelectronics EVLSRK1001-PF

Overview

EVLSRK1001-PF from STMicroelectronics is a demonstration board for the SRK1001 adaptive synchronous rectification controller, designed to replace secondary-side diodes in flyback converters. It integrates the SRK1001 IC and a BSC110N15NS5 150 V / 11 mΩ N-channel PowerFLAT 5×6 MOSFET, supports up to 500 kHz switching, operates from 3.5–32 V VCC, and implements fixed turn-on with adaptive turn-off timing.

For engineers reviewing the EVLSRK1001-PF datasheet, EVLSRK1001-PF pinout, EVLSRK1001-PF application, or EVLSRK1001-PF equivalent, this board enables rapid evaluation of QR and FF flyback topologies with configurable blanking (1.44 µs TON, 3 µs TOFF), DVS sensing at 185 V AMR, and remote ON/OFF via DIS/SYNC pin.

Technical Context

The EVLSRK1001-PF implements secondary-side synchronous rectification using the SRK1001 controller, which senses drain-to-source voltage (DVS) to trigger gate drive for the integrated BSC110N15NS5 MOSFET. It supports both quasi-resonant (QR) and fixed-frequency (FF) flyback operation, with blanking times set by external resistors on TON (120 kΩ → 1.44 µs) and TOFF (100 kΩ → 3 µs) pins.

Configuration for FF mode requires adding a 100 pF capacitor at C3; QR mode is pre-configured. The DIS/SYNC pin enables remote control via an onboard NPN transistor (Q2), activated by removing zero-ohm resistor R9. VCC range (3.5–32 V) and DVS threshold (185 V AMR) are fixed internal parameters.

Key Specifications

Availability

EVLSRK1001-PF is available at Aetrix Electronics and suitable for flyback converter evaluation, QR/FF topology prototyping, and synchronous rectifier replacement in AC-DC adapters, USB PD chargers, and industrial power supplies requiring stable component supply and fast design validation.

Supply support for EVLSRK1001-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, Switzerland, designing and manufacturing microcontrollers, analog ICs, power devices, and silicon solutions for automotive, industrial, and consumer applications.

The SRK1001 product line targets high-efficiency secondary-side synchronous rectification in isolated flyback converters, specifically addressing thermal and efficiency limitations of Schottky diodes in medium-power AC-DC systems.

FAQ

What is the primary function of the EVLSRK1001-PF board?

The EVLSRK1001-PF is a demonstration board that evaluates the SRK1001 synchronous rectification controller in flyback converters. It replaces conventional output rectifier diodes with an actively controlled N-channel MOSFET (BSC110N15NS5) to reduce conduction losses and improve efficiency, especially in QR and mixed DCM-CCM modes.

How do I configure the board for fixed-frequency (FF) operation?

To configure for FF operation, install a 100 pF capacitor at location C3. The board ships pre-configured for quasi-resonant (QR) mode. No other component changes are required; the TON and TOFF blanking times remain valid for FF use as specified in the SRK1001 datasheet.

Can the DIS/SYNC pin be used for remote control?

Yes - remote ON/OFF control is enabled by removing zero-ohm resistor R9 and applying a signal to the DIS/SYNC pin. The board includes an onboard NPN transistor (Q2, BC847) connected to this pin, allowing direct TTL-level control without external level-shifting circuitry.

What is the role of the BSC110N15NS5 MOSFET on this board?

The BSC110N15NS5 is a 150 V, 11 mΩ N-channel PowerFLAT 5×6 MOSFET serving as the synchronous rectifier switch. It is directly driven by the SRK1001's internal gate driver and replaces the secondary-side diode in flyback converters, reducing forward voltage drop from ~0.5 V to <0.1 V under typical load, thereby improving efficiency and thermal performance.