STMicroelectronics STEVAL-ILL026V1

Overview

STEVAL-ILL026V1 from STMicroelectronics is a 3 W non-isolated offline LED driver demonstration board based on the VIPer22A-E IC, designed to drive three 1 W LEDs in series with ±5% constant current accuracy at 350 mA, operating from 90–265 VRMS AC input, and featuring overtemperature, LED open-circuit, and short-circuit protection for lighting applications.

For engineers reviewing the STEVAL-ILL026V1 datasheet, STEVAL-ILL026V1 pinout, STEVAL-ILL026V1 application, or STEVAL-ILL026V1 equivalent, this board serves as a validated reference design for cost-sensitive, capacitor-free 230 VAC LED drivers requiring EN55015 and EN61000-3-2 compliance without electrolytic bulk capacitors.

Technical Context

The board implements a flyback-derived, non-isolated buck-boost topology using the VIPer22A-E - an integrated high-voltage PWM controller + 730 V MOSFET - enabling direct AC/DC conversion without optocoupler feedback. It uses primary-side sensing via the FB pin to regulate LED current with ±5% tolerance across line and load variations.

Protections are hardware-based: thermal shutdown triggers at ~145 °C (via NTC on heatsink), LED open-circuit detection disables switching when FB voltage exceeds threshold, and short-circuit protection clamps output current by limiting peak drain current through R5 (1.5 Ω, 1%, sense resistor).

Key Specifications

Availability

STEVAL-ILL026V1 is available at Aetrix Electronics and suitable for LED retrofit lamps, architectural accent lighting, and emergency signage requiring stable component supply, long-life operation, and regulatory-compliant AC/DC conversion.

Supply support for STEVAL-ILL026V1 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, sensors, and analog devices for industrial, automotive, and consumer markets.

This board belongs to ST's STEVAL lighting evaluation platform family, developed to accelerate adoption of energy-efficient, standards-compliant LED drivers using VIPer and L6562-based controllers.

FAQ

What is the maximum total forward voltage supported by STEVAL-ILL026V1?

The board supports up to 9.6 V total forward voltage (3 × 1 W LEDs at ~3.2 V each) while maintaining 350 mA regulation. Exceeding this reduces efficiency and may trigger overvoltage protection due to FB pin saturation above 2.5 V.

Does STEVAL-ILL026V1 require external programming or configuration?

No. The board operates out-of-the-box with fixed component values defining current regulation (R5 = 1.5 Ω), startup timing (C1 = 22 µF), and feedback gain (R2/R4 network). No firmware, trimmers, or configuration jumpers are needed.

Can STEVAL-ILL026V1 be used with 115 VAC input?

Yes. Its 90–265 VRMS input range covers both 115 VAC and 230 VAC mains. Output current remains stable at 350 mA ±5% across this range, verified per the data brief's test conditions and schematic component ratings.

What thermal management provisions does the board include?

The board uses an NTC thermistor (R7 = 10 Ω, 1 W, 10%) mounted near the VIPer22A-E heatsink pad to enable overtemperature shutdown at ~145 °C. PCB copper pour under the VIPer22A-E and DRAIN pad provides passive conduction cooling without forced airflow.