STMicroelectronics EVLSRK1004C

Overview

EVLSRK1004C from STMicroelectronics is an evaluation board for the SRK1004C secondary-side synchronous rectification controller, optimized for Non-Complementary Active Clamp Flyback (NC-ACF) converters. It integrates the SRK1004C IC and a BSC093N15NS5 PowerFLAT 5×6 N-channel MOSFET (150 V V_DS, 87 A I_D, 9.3 mΩ R_DS(on) @ 10 V), supports up to 500 kHz switching, and operates with 4–36 V supply voltage.

For engineers reviewing the EVLSRK1004C datasheet, EVLSRK1004C pinout, EVLSRK1004C application, or EVLSRK1004C equivalent, this board enables rapid validation of SR MOSFET replacement in low-side NC-ACF topologies, drain-source voltage sensing (190 V AMR), fast short-circuit detection, and dual-configurable (low/high-side) SR gate drive implementation.

Technical Context

The EVLSRK1004C implements a zero-current-switching (ZCS)-based control scheme: the SR MOSFET turns on at body-diode conduction onset and turns off as secondary current approaches zero. It supports both low-side (GND-referenced) and high-side (output-referenced) configurations via jumper-selectable DVS sensing and SCP pin routing.

Power is derived directly from the converter output in low-side mode; in high-side mode, auxiliary winding supply is recommended with R5 > 47 kΩ to configure V_OUT,SC (e.g., 150 kΩ sets 2 V threshold). The board includes integrated 4.7 µF/50 V and 1 µF/25 V X7R ceramic input/output decoupling capacitors.

Key Specifications

Availability

EVLSRK1004C is available at Aetrix Electronics and suitable for USB-C PD adapters, industrial AC-DC power supplies, and telecom offline SMPS requiring stable component supply, fast SR validation cycles, and production-ready reference implementation.

Supply support for EVLSRK1004C 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 management ICs, analog devices, and silicon carbide solutions for industrial, automotive, and power conversion markets.

The SRK1004x family targets high-efficiency secondary-side synchronous rectification in resonant and active-clamp flyback topologies, with variant-specific gate-drive voltages to match logic-level and standard-level N-MOSFETs across diverse output voltage ranges.

FAQ

Can EVLSRK1004C be used in Quasi-Resonant (QR) flyback converters?

Yes. The SRK1004C controller on this board supports both Non-Complementary Active Clamp Flyback and Quasi-Resonant flyback topologies. Its ZCS-based turn-on/turn-off timing adapts to QR valley-switching waveforms, and the board's default low-side configuration is compatible with standard QR transformer layouts without modification.

What is the purpose of resistor R5 on EVLSRK1004C?

R5 configures the short-circuit protection (SCP) threshold voltage (V_OUT,SC) when operating in high-side configuration. With R5 > 47 kΩ (e.g., 150 kΩ), V_OUT,SC = 2 V is set to detect output short events. In low-side mode, R5 = 22 kΩ disables SCP functionality, as the board derives power directly from the output and does not require auxiliary sensing.

Does EVLSRK1004C support high-side SR configuration out of the box?

No. The board ships configured for low-side operation by default (D2 shorted, R5 = 22 kΩ). To enable high-side configuration, users must remove the D2 short, install R5 > 47 kΩ, and power the board from an auxiliary winding - per Section 2 of DB5132 Rev 2. No PCB rework is needed, but external wiring and bias supply are required.

Is the BSC093N15NS5 MOSFET soldered and field-replaceable on EVLSRK1004C?

Yes. The BSC093N15NS5 is surface-mounted in PowerFLAT 5×6 package and fully assembled on the board. Its footprint matches JEDEC MO-229WEED-1, allowing qualified users to desolder and replace it with alternative 150 V N-MOSFETs - provided thermal layout, gate drive strength, and DVS sensing compatibility are verified per SRK1004C's 5 V gate drive capability.