STMicroelectronics STEVAL-ISA019V3

Overview

STEVAL-ISA019V3 from STMicroelectronics is a 3-phase auxiliary power supply demonstration board featuring an 80 W quasi-resonant flyback SMPS using the L6565N controller and STC04IE170HP 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-ISA019V3 datasheet, STEVAL-ISA019V3 pinout, STEVAL-ISA019V3 application, or STEVAL-ISA019V3 equivalent, this board serves as a validated reference design for high-input-voltage, wide-range industrial auxiliary supplies requiring secondary-side regulation, mixed-mode (DCM/CCM) operation, and RoHS-compliant 3-phase system integration.

Technical Context

The board implements a quasi-resonant flyback topology operating in mixed discontinuous and continuous conduction modes to maintain regulation across 180–600 VAC input. It uses primary-side sensing via ZCD and secondary-side feedback through PC817 optocoupler and TL431 shunt regulator for precise 24 V output control.

L6565N provides adaptive zero-current detection, frequency foldback, and built-in protections including overvoltage lockout and current limiting. The STC04IE170HP ESBT enables robust switching at >50 kHz with high breakdown voltage (1700 V) and low gate charge, optimized for high-DC-link applications typical in 3-phase motor drives and industrial PLCs.

Key Specifications

Availability

STEVAL-ISA019V3 is available at Aetrix Electronics and suitable for industrial motor drives, 3-phase PLC power supplies, and high-voltage auxiliary converter development requiring stable component supply, rapid prototyping validation, and regulatory-compliant reference designs.

Supply support for STEVAL-ISA019V3 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 devices, analog ICs, and silicon solutions for industrial, automotive, and consumer markets.

This board belongs to ST's STEVAL evaluation platform family, engineered specifically to accelerate adoption of ST's high-voltage power ICs and discrete devices in ruggedized industrial power conversion applications.

FAQ

What is the primary topology implemented on STEVAL-ISA019V3?

The board implements a quasi-resonant flyback converter operating in mixed discontinuous and continuous conduction mode (DCM/CCM), enabling stable regulation across its 180–600 VAC input range while minimizing switching losses and EMI. This topology leverages the L6565N's adaptive ZCD circuit and the STC04IE170HP's high-voltage capability.

Can STEVAL-ISA019V3 be used with single-phase AC input?

Yes - though designed for 3-phase auxiliary supply validation, the board accepts any AC input between 180 VAC and 600 VAC, including single-phase 230 VAC or 400 VAC sources. Its wide input range and EN60950 compliance make it suitable for both single- and three-phase test environments without hardware modification.

Does the board include protection features beyond overvoltage?

Yes - the L6565N controller integrates cycle-by-cycle current limiting, overvoltage lockout (OVP), and thermal shutdown. The design also incorporates NTC-based inrush current limiting (NTC1), fuse F2 (T1A), and input rectifier bridge D1–D4 with STTH108 diodes rated for 10 A/800 V peak inverse voltage.

Is the 24 V output isolated and regulated?

Yes - the output is fully isolated via the main transformer (DELTA 86H-6017C) and tightly regulated using secondary-side feedback: TL431 provides precision voltage reference, and PC817 optocoupler transmits error signal to the L6565N's COMP pin, achieving <±3% output tolerance across line and load variations.