STMicroelectronics STEVAL-ISA138V1

Overview

STEVAL-ISA138V1 from STMicroelectronics is a 90 W, universal-input (90–264 Vac), power-factor-corrected AC-DC evaluation board designed for laptop adapter applications. It implements a two-stage architecture: an L6563H-controlled boost PFC front-end and an L6699-driven LLC resonant half-bridge converter, delivering 19 V at 4.75 A with EN61000-3-2 Class-D harmonic compliance and ENERGY STAR 2.0 / ErP Lot 6 Tier 2 efficiency certification.

For engineers reviewing the STEVAL-ISA138V1 datasheet, STEVAL-ISA138V1 pinout, STEVAL-ISA138V1 application, or STEVAL-ISA138V1 equivalent, this board serves as a validated reference design for high-efficiency, low-no-load-consumption external power supplies targeting premium portable computing systems - with full schematic, BOM, and layout documentation provided by ST.

Technical Context

The board implements a continuous-conduction-mode (CCM) boost PFC stage using the L6563H controller, which supports wide input voltage range and delivers stable DC bus voltage to the downstream LLC stage. The L6699D drives a resonant half-bridge with adaptive dead-time control, anti-capacitive mode protection, and safe-start sequencing to prevent hard switching at startup.

Input rectification uses GBU8J bridge and NTC inrush limiting; output rectification employs STPS30H60CFP Schottky diodes; feedback is closed via TL431AIZ and optocoupler SFH617A-4. EMI filtering meets EN55022 Class-B, and safety complies with EN60950.

Key Specifications

Availability

STEVAL-ISA138V1 is available at Aetrix Electronics and suitable for laptop adapter development, industrial AC-DC reference design validation, and energy-efficient EPS qualification requiring stable component supply and full regulatory documentation support.

Supply support for STEVAL-ISA138V1 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 ICs, analog devices, and silicon solutions for industrial, automotive, and consumer markets.

This evaluation board belongs to ST's STEVAL (ST Evaluation) series - purpose-built reference designs that demonstrate optimal implementation of ST's proprietary controllers (L6563H, L6699D) for high-efficiency, standards-compliant AC-DC conversion.

FAQ

What is the primary function of the STEVAL-ISA138V1 evaluation board?

The STEVAL-ISA138V1 is a fully assembled, tested reference design for a 90 W, PFC-enabled AC-DC adapter targeting laptop power supplies. It integrates ST's L6563H (PFC controller) and L6699D (LLC resonant controller) to deliver regulated 19 V output with high efficiency, low no-load consumption, and full regulatory compliance including EN61000-3-2 and ENERGY STAR 2.0.

Does STEVAL-ISA138V1 include complete design files?

Yes - ST provides the full design package including schematic (PDF), PCB layout (Gerber), BOM, bill-of-material notes, test reports, and application note AN4312. All files are publicly available on st.com under DocID025490 and are intended for direct reuse in commercial adapter development.

Can STEVAL-ISA138V1 be modified for different output voltages?

Yes - output voltage is set by the TL431AIZ + optocoupler feedback network (R14, R15, R40, C36). Adjusting the resistor divider changes regulation point; however, transformer turns ratio (T1, 1860.0076) and output rectifier ratings (STPS30H60CFP) must be re-evaluated for outputs significantly above 19 V or higher current.

What safety and EMC testing has been performed on this board?

The board was validated per EN60950-1 for safety (reinforced insulation, spacing, thermal performance) and EN55022 Class-B for conducted/radiated emissions. Harmonic current distortion meets EN61000-3-2 Class-D. Test data and layout guidelines are documented in the official data brief (DocID025490 Rev 1).