STMicroelectronics STEVAL-ISA019V1

Overview

STEVAL-ISA019V1 from STMicroelectronics is a 3-phase auxiliary power supply evaluation board featuring an 80 W quasi-resonant flyback SMPS using the L6565N PWM controller and STC04IE170HV ESBT switch, delivering 24 V at 3.3 A from 180–600 VAC input, with >80% efficiency and EN60950 safety compliance.

For engineers reviewing the STEVAL-ISA019V1 datasheet, STEVAL-ISA019V1 schematic, STEVAL-ISA019V1 application, or STEVAL-ISA019V1 alternative boards, this evaluation platform supports rapid validation of high-input-voltage, three-phase auxiliary power architectures in industrial motor drives, energy metering, and grid-connected inverters where wide-range AC input tolerance and dual-mode (DCM/CCM) flyback operation are critical.

Technical Context

The board implements a mixed-mode quasi-resonant flyback topology that dynamically transitions between discontinuous conduction mode (DCM) and continuous conduction mode (CCM) to maintain regulation across 180–600 VAC input, enabling stable 24 V output under varying load and line conditions typical of 3-phase rectified DC bus environments.

It integrates secondary-side regulation via PC817 optocoupler and TL431 shunt regulator, with primary-side control by the L6565N - a current-mode quasi-resonant controller featuring zero-current detection (ZCD), adjustable frequency foldback, and built-in protections including overvoltage, overcurrent, and thermal shutdown.

Key Specifications

Availability

STEVAL-ISA019V1 is available at Aetrix Electronics and suitable for industrial motor drives, smart energy meters, and grid-tied solar inverters requiring stable component supply and validated reference designs for high-input-voltage auxiliary power.

Supply support for STEVAL-ISA019V1 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 silicon solutions for automotive, industrial, and power applications with emphasis on reliability and system integration.

This board belongs to ST's STEVAL evaluation platform family, engineered specifically to accelerate prototyping and qualification of high-voltage power conversion topologies in three-phase industrial infrastructure.

FAQ

What is the primary topology implemented on STEVAL-ISA019V1?

The board uses a quasi-resonant flyback converter operating in mixed DCM/CCM mode, optimized for wide-input 3-phase rectified voltage (180–600 VAC). It leverages zero-current switching via the L6565N's ZCD pin and STC04IE170HV's high-voltage ESBT structure to achieve soft-switching across the entire input range.

Can STEVAL-ISA019V1 be used with single-phase input?

Yes - though designed for 3-phase auxiliary power, the board accepts any AC input between 180 VAC and 600 VAC, including single-phase 230 VAC or 400 VAC lines. Its input fuse (F1) and bridge rectifier (D1–D4) support both configurations without modification.

Which controller IC manages primary-side regulation?

The L6565N PWM controller handles primary-side timing and protection functions, while regulation is closed via secondary-side feedback: TL431 compares 24 V output against internal 2.5 V reference, driving PC817 optocoupler to adjust L6565N's COMP pin voltage and modulate duty cycle.

Does the board include input surge or EMI filtering components?

No - STEVAL-ISA019V1 omits input EMI filters and MOV-based surge suppression to maintain flexibility for end-system integration. Users must add external line filters, X/Y capacitors, and varistors per their final application's EMC and safety requirements before deployment.