STMicroelectronics EVALHVLED805

Overview

EVALHVLED805 from STMicroelectronics is a demonstration board built around the HVLED805 primary-side regulated quasi-resonant flyback LED driver IC, designed for 230 VAC European mains input. It delivers 350 mA ±5% constant current to 1–3串联 white LEDs with ≤10% current ripple, 12 V max output voltage, and >70% efficiency (2–3 LEDs), targeting compact, cost-sensitive LED lighting modules.

For engineers reviewing the EVALHVLED805 datasheet, EVALHVLED805 pinout, EVALHVLED805 application, or EVALHVLED805 equivalent, this page provides verified board-level specifications, transformer design details, measured startup/efficiency behavior, BOM component sourcing notes, and functional context for LED driver evaluation in offline AC-DC lighting systems.

Technical Context

The EVALHVLED805 implements a primary-side regulation (PSR) quasi-resonant flyback topology using the integrated HVLED805 controller with an internal 800 V MOSFET. It eliminates optocoupler feedback by sensing reflected auxiliary winding voltage for precise output current control.

Startup is achieved via internal high-voltage current generator (no external bias circuit required); operation maintains ≥70 kHz minimum switching frequency and achieves <100 mW no-load input power. Efficiency drops below 70% only with single-LED load due to V_CC self-supply dissipation at low output voltage.

Key Specifications

Availability

EVALHVLED805 is available at Aetrix Electronics and suitable for LED lighting development, power supply reference design validation, and PSR flyback topology evaluation requiring stable component supply, traceable BOM sourcing, and documented performance under 230 VAC conditions.

Supply support for EVALHVLED805 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 analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

The EVALHVLED805 belongs to ST's HVLED family of primary-side regulated LED drivers, engineered specifically for low-cost, compact, and reliable offline LED lighting applications in residential and commercial settings.

FAQ

What is the purpose of the EVALHVLED805 demonstration board?

The EVALHVLED805 is a fully assembled, tested reference design board that demonstrates the HVLED805 IC's capability to drive 1–3 white LEDs at 350 mA from 230 VAC mains using primary-side regulation. It includes all critical components-transformer, rectifier, snubber, and layout-optimized PCB-to validate performance, efficiency, and startup behavior without requiring additional hardware.

Can EVALHVLED805 operate with 115 VAC input?

No. The EVALHVLED805 is configured for 185–265 VAC input per its transformer turns ratio, snubber design, and HVLED805 startup threshold. Its transformer (Magnetica 1921.0013 Rev04) and input bridge (MB6S) are rated for 230 VAC nominal operation; attempting 115 VAC will result in insufficient auxiliary winding voltage for IC bias and failure to start or regulate.

How is output current accuracy achieved without an optocoupler?

Accuracy is achieved through primary-side regulation: the HVLED805 senses the reflected voltage on the auxiliary winding during demagnetization, correlates it to output current via stored calibration coefficients, and adjusts switching timing to maintain 350 mA ±5%. This eliminates optocoupler drift, aging, and cost while preserving tight regulation across line and load variations.

What transformer parameters are critical for replicating this design?

Critical parameters include primary inductance (2.6 mH ±15%), primary-to-secondary turns ratio (7.68 ±5%, i.e., 123:16), primary-to-auxiliary ratio (5.59 ±5%, i.e., 123:22), air gap (~70 µm), and inter-winding insulation rated for 4 kV. Deviations beyond tolerance degrade regulation accuracy, efficiency, or safety isolation compliance.