STMicroelectronics STEVAL-ISA018V1

Overview

STEVAL-ISA018V1 from STMicroelectronics is a 150 W (240 W peak) resonant half-bridge SMPS demonstration board based on the L6599 high-voltage resonant controller, delivering regulated 24 V ±2% output at up to 6 A continuous (10 A peak), with >90% efficiency and EN60950/EN55014 compliance for industrial power supply evaluation.

For engineers reviewing the STEVAL-ISA018V1 datasheet, STEVAL-ISA018V1 schematic, STEVAL-ISA018V1 application, or STEVAL-ISA018V1 equivalent, this board enables rapid validation of resonant LLC topology performance, thermal behavior under overload, secondary-side regulation using TSM1011, and EMI-compliant layout practices in high-efficiency AC-DC conversion designs.

Technical Context

The board implements a voltage-fed half-bridge LLC resonant converter with an L6599-driven primary stage and synchronous rectification on the secondary side. It supports dual-input ranges (85–185 Vac with doubler, 185–265 Vac direct) and uses a resonant LC tank to achieve zero-voltage switching across line and load conditions.

Output regulation is performed by the TSM1011 programmable shunt regulator on the secondary side, enabling precise 24 V ±2% setpoint control and square-wave current limiting. Overload protection relies on PTC thermistors integrated into the output rectifier path, not IC-based current sensing.

Key Specifications

Availability

STEVAL-ISA018V1 is available at Aetrix Electronics and suitable for industrial AC-DC power supply design, resonant topology evaluation, and high-efficiency SMPS qualification requiring stable component supply and documented reference implementation.

Supply support for STEVAL-ISA018V1 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 devices, and silicon solutions for industrial, automotive, and consumer applications.

This board belongs to ST's STEVAL (ST Evaluation) series, developed specifically to demonstrate high-efficiency resonant power conversion topologies using ST's proprietary controllers like L6599 for industrial-grade SMPS design validation.

FAQ

Is STEVAL-ISA018V1 still in active production?

No - STEVAL-ISA018V1 is marked obsolete per ST's official documentation (Doc ID 17434 Rev 1, April 2010). It remains available through authorized distributors and Aetrix Electronics for legacy design support, but no new revisions or manufacturing runs are planned.

Can STEVAL-ISA018V1 be used for 12 V output designs?

No - the board is hardwired for 24 V ±2% output via fixed resistor divider on the TSM1011 feedback network and transformer turns ratio. Output voltage change requires physical modification of both feedback resistors and secondary winding configuration, voiding compliance certifications.

What is the role of the TSM1011 on this board?

The TSM1011 serves as a programmable shunt regulator on the secondary side, providing precise 24 V output regulation and square-wave current limiting. It drives the optocoupler feedback signal to the L6599 primary controller, enabling isolated voltage control without secondary-side PWM ICs.

Does this board include overtemperature protection?

Yes - overtemperature protection is implemented via PTC thermistors mounted in series with the output rectifiers. When temperature exceeds threshold, PTC resistance rises sharply, limiting output current to ≤10 A during overload, independent of the TSM1011 regulation loop.