STMicroelectronics STEVAL-ISA166V1

Overview

STEVAL-ISA166V1 from STMicroelectronics is an evaluation board for the SRK2001 adaptive synchronous rectification controller, designed for secondary-side full-wave rectification in LLC resonant converters with center-tapped transformer windings. It integrates two STP77N6F6 60 V / 7 mΩ N-channel MOSFETs in TO-220 packages, supports up to 500 kHz switching frequency, operates from 4.5 V to 32 V VCC, and implements independent dual gate drives with interlock logic to prevent shoot-through.

For engineers reviewing the STEVAL-ISA166V1 datasheet, STEVAL-ISA166V1 pinout, STEVAL-ISA166V1 application, or STEVAL-ISA166V1 equivalent, this board enables rapid validation of adaptive SR timing, ZCD_OFF–triggered fast turn-off under above-resonance conditions, and high-efficiency replacement of diode-based rectifiers in high-frequency LLC power supplies.

Technical Context

The board implements the SRK2001's proprietary adaptive control architecture, which dynamically adjusts SR MOSFET turn-on based on drain-source voltage (V_DS) zero-crossing detection and turn-off using both adaptive delay and a dedicated ZCD_OFF comparator for sub-100 ns forced turn-off during over-resonant operation. Each gate driver delivers >1 A peak current with independent SVS1/DVS1 and SVS2/DVS2 sensing paths.

It targets LLC converters operating at 200–500 kHz with center-tapped secondaries, where precise SR timing minimizes conduction loss and reverse-recovery energy. The interlock logic ensures strict non-overlap between GD1 and GD2 outputs, eliminating cross-conduction risk even during transient load steps.

Key Specifications

Availability

STEVAL-ISA166V1 is available at Aetrix Electronics and suitable for LLC resonant converter development, high-efficiency AC/DC adapter qualification, and server PSU reference design validation requiring stable component supply and documented SR timing behavior.

Supply support for STEVAL-ISA166V1 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 microcontrollers, power ICs, analog devices, and silicon solutions for industrial, automotive, and consumer markets.

The STEVAL-ISA166V1 belongs to ST's power conversion evaluation board portfolio, specifically engineered to accelerate adoption of adaptive synchronous rectification in high-frequency LLC resonant converters targeting >95% efficiency at 200–500 kHz.

FAQ

What is the primary function of the SRK2001 controller on this board?

The SRK2001 implements adaptive synchronous rectification control for LLC resonant converters with center-tapped secondary windings. It senses V_DS of two N-channel MOSFETs to trigger precise turn-on and uses both adaptive delay and a dedicated ZCD_OFF comparator for ultra-fast turn-off, minimizing reverse conduction losses in high-frequency operation.

Can STEVAL-ISA166V1 be used with non-ST synchronous rectifier controllers?

No - the board is purpose-built for the SRK2001 IC and its specific pinout, gate drive timing, and sensing interface (SVS1/DVS1/SVS2/DVS2). Its layout, component selection (e.g., R505/R506 zero-ohm jumpers), and interlock logic are not compatible with other SR controllers such as SRK1001 or competing parts from Infineon or ON Semiconductor.

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

The ZCD_OFF comparator triggers immediate gate turn-off when V_DS rises rapidly during above-resonance operation, reducing reverse conduction time to <100 ns. This prevents energy loss and thermal stress in the SR MOSFETs during light-load or transient conditions where adaptive delay alone would cause excessive reverse current.

Does the board support adjustable dead-time or programmable turn-on thresholds?

No - turn-on timing is fully adaptive and determined by internal V_DS sensing thresholds; turn-off uses fixed ZCD_OFF hysteresis and a factory-trimmed adaptive delay. The PROG pin (Pin 9) is unpopulated and not used on this board; no external programming resistors or capacitors are included for timing adjustment.