STMicroelectronics EVL6699-HVSL

Overview

EVL6699-HVSL from STMicroelectronics is an evaluation board for a 150 W, 1 A LED driver implementing a two-stage architecture: a transition-mode PFC pre-regulator (L6564H) followed by a half-bridge LCC resonant converter (L6699D). It delivers 150 V at 1 A continuous output, achieves >91% efficiency at full load, complies with EN61000-3-2 Class-C harmonics and EN55022 Class-C conducted EMC, and supports analog, resistive, and PWM dimming for high-power street lighting systems.

For engineers reviewing the EVL6699-HVSL datasheet, EVL6699-HVSL pinout, EVL6699-HVSL application, or EVL6699-HVSL equivalent, this board provides validated reference design data for LCC-based constant-current LED drivers with auto-restart protection, flicker-free PWM dimming down to 1%, and no auxiliary SMPS requirement.

Technical Context

The board implements a front-end transition-mode PFC stage using the L6564H controller, delivering regulated high-voltage DC bus (≈400 V) with THD <10% at 230 Vac and EN61000-3-2 Class-C compliance. The downstream half-bridge LCC resonant converter-driven by the L6699D-operates in zero-voltage switching (ZVS) mode to achieve high efficiency (>91%) and low EMI.

Feedback is implemented via dual loops: constant current (CC) and constant voltage (CV), with optocoupler-isolated regulation using TLVH431 references and SFH617A-2 optocouplers. Protection features include LED short-circuit, open-string, and regulation-loop-failure detection-all with auto-restart functionality.

Key Specifications

Availability

EVL6699-HVSL is available at Aetrix Electronics and suitable for high-power LED street lighting, industrial area lighting, and outdoor architectural lighting requiring stable component supply, reference-grade validation, and regulatory-compliant design starting points.

Supply support for EVL6699-HVSL 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 chips, and silicon carbide solutions for industrial, automotive, and power applications.

EVL6699-HVSL belongs to ST's LED lighting evaluation platform family, engineered to accelerate development of high-efficiency, standards-compliant AC/DC LED drivers for outdoor and high-bay lighting applications.

FAQ

What is the primary topology used in the EVL6699-HVSL evaluation board?

The board uses a two-stage topology: a transition-mode PFC pre-regulator based on the L6564H IC, followed by a half-bridge LCC resonant converter controlled by the L6699D. This architecture delivers high efficiency, low THD, and inherent current-source behavior ideal for driving LED strings without additional current-sensing complexity.

Does the EVL6699-HVSL require an auxiliary power supply for biasing the control circuitry?

No. The design eliminates the need for a separate auxiliary SMPS (e.g., VIPer-based supply) by deriving bias power directly from the PFC output bus via integrated startup and VCC regulation circuits within the L6564H and L6699D controllers, reducing component count and improving reliability.

How does the board implement flicker-free PWM dimming down to 1%?

Flicker-free operation is achieved by maintaining continuous DC current through the LED string during PWM dimming cycles-even at 1% duty cycle-using the L6699D's adaptive dead-time control and resonant tank dynamics. This avoids current interruption that causes visible flicker, meeting IEEE 1789-2015 low-risk guidelines.

Can the EVL6699-HVSL be modified for different output voltages or currents?

Yes. Output voltage and current are set by transformer turns ratio, resonant tank components (L2, C14, C15), and feedback resistor dividers (e.g., R119/R120 for CV, R17/R139 for CC). ST provides optimization guidelines in DB3921, including rework points (e.g., R29/R30 removal, RC network on RFMIN) for tuning performance across 100–200 W range.