STMicroelectronics STEVAL-ISA169V1

Overview

STEVAL-ISA169V1 from STMicroelectronics is an evaluation board for the SRK2001L adaptive synchronous rectification controller, designed for secondary-side full-wave rectification in LLC resonant converters with center-tapped transformer windings. It integrates two STL140N4LLF5 40 V / 3.1 mΩ PowerFlat N-channel MOSFETs, supports up to 500 kHz switching, operates from 4.5–32 V VCC, and implements independent dual gate drives with interlock logic to prevent shoot-through.

For engineers reviewing the STEVAL-ISA169V1 datasheet, STEVAL-ISA169V1 schematic, STEVAL-ISA169V1 application notes, or STEVAL-ISA169V1 alternative evaluation boards, this board enables rapid validation of adaptive SR timing, ZCD-based fast turn-off under above-resonance conditions, and replacement of diode rectifiers in high-efficiency 12 V/24 V LLC power supplies.

Technical Context

The board implements the SRK2001L's proprietary adaptive turn-on/turn-off algorithm, which senses drain-source voltage (DVS) and source-voltage slope (SVS) on each SR leg to dynamically adjust conduction timing without external timing components. Its ZCD_OFF comparator triggers sub-100 ns MOSFET turn-off during fast load transients or above-resonance operation.

Each gate driver delivers >1 A peak current into 1 nF capacitive load at 500 kHz, supporting logic-level drive for low-R_DS(on) PowerFlat MOSFETs. The interlock logic ensures strict non-overlap between GD1 and GD2 outputs, eliminating cross-conduction risk in center-tap configurations.

Key Specifications

Availability

STEVAL-ISA169V1 is available at Aetrix Electronics and suitable for LLC resonant converter development, high-efficiency AC-DC adapter qualification, and synchronous rectifier replacement validation requiring stable component supply and documented reference design support.

Supply support for STEVAL-ISA169V1 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, designing and manufacturing microcontrollers, power ICs, analog chips, and silicon carbide solutions for industrial, automotive, and consumer applications.

The STEVAL-ISA169V1 belongs to ST's power conversion evaluation board portfolio, developed specifically to accelerate adoption of adaptive synchronous rectification in high-frequency LLC topologies targeting >94% efficiency at light-to-full load.

FAQ

What is the primary function of the SRK2001L controller on this board?

The SRK2001L implements adaptive synchronous rectification control for LLC resonant converters with center-tapped secondary windings. It senses DVS and SVS signals on each SR leg to autonomously determine optimal MOSFET turn-on and turn-off timing, eliminating need for fixed-delay or transformer auxiliary winding sensing.

Can STEVAL-ISA169V1 be used with non-ST LLC controllers?

Yes - the board interfaces via standard gate-drive signals and does not require proprietary communication. It accepts external VCC (4.5–32 V), GND, and transformer secondary center-tap connections, making it compatible with third-party LLC controllers that provide isolated center-tap secondary windings and appropriate bias supply.

What is the role of the ZCD_OFF comparator in system reliability?

The ZCD_OFF comparator monitors drain-source voltage zero-crossing and forces immediate gate turn-off when above-resonance operation or fast load steps cause reverse current flow. This prevents body-diode conduction and thermal stress in the STL140N4LLF5 MOSFETs, improving long-term reliability under dynamic load conditions.

Does the board support adjustable dead-time or external timing components?

No - the SRK2001L uses fully autonomous adaptive algorithms with no external timing resistors or capacitors. Dead-time is dynamically determined by real-time DVS/SVS analysis and ZCD_OFF activation. The PROG pin is unused on this board; EN pin enables/disables both gate drivers simultaneously.