HVLED805中文资料具有一次感应功能的5W离线LED驱动器数据手册ST规格书

描述 Description

The HVLED805 is a high-voltage primary switcher intended for operating directly from the rectified mains with minimum external parts to provide an efficient, compact and cost effective solution for LED driving. It combines a high-performance low-voltage PWM controller chip and an 800V, avalanche-rugged power MOSFET, in the same package.

The PWM is a current-mode controller IC specifically designed for ZVS (Zero Voltage Switching) fly-back LED drivers, with constant output current (CC) regulation using primary-sensing feedback. This eliminates the need for the opto-coupler, the secondary voltage reference, as well as the current sense on the secondary side, still maintaining a good LED current accuracy. Moreover it guarantees a safe operation when short circuit of one or more LEDs occurs.

In addition, the device can also provide a constant output voltage regulation (CV): it makes the application able to work safely when the LED string opens due to a failure.

Quasi-resonant operation is achieved by means of a transformer demagnetization sensing input that triggers MOSFET’s turn-on. This input serves also as both output voltage monitor, to perform CV regulation, and input voltage monitor, to achieve mains-independent CC regulation (line voltage feed forward).

The maximum switching frequency is top-limited below 166 kHz, so that at medium-light load a special function automatically lowers the operating frequency still maintaining the operation as close to ZVS as possible. At very light load, the device enters a controlled burst-mode operation that, along with the built-in high-voltage start-up circuit and the low operating current of the device, helps minimize the residual input consumption.

Although an auxiliary winding is required in the transformer to correctly perform CV/CC regulation, the chip is able to power itself directly from the rectified mains. This is useful especially during CC regulation, where the fly-back voltage generated by the winding drops.

In addition to these functions that optimize power handling under different operating conditions, the device offers protection features that considerably increase end-product’s safety and reliability: auxiliary winding disconnection or brownout detection and shorted secondary rectifier or transformer’s saturation detection. All of them are auto restart mode.

特性 Features

• 800 V, avalanche rugged internal power MOSFET
• 5% accuracy on constant LED output current with primary control
• Optocoupler not needed
• Quasi-resonant (QR) zero voltage switching (ZVS) operation
• Internal HV start-up circuit
• Open or short LED string management
• Automatic self supply
• Input voltage feed-forward for mains independent cc regulation

简介

HVLED805属于集成电路（IC）的LED驱动器。由制造生产的HVLED805LED 驱动器器件属于 LED 驱动器电源管理集成电路 (PMIC) 系列，可通过标称固定电压的电源为负载（通常为发光二极管）提供电流，并且电流可控。它与用于电压调节的类似产品的主要区别在于，这类器件提供较低的反馈电压（以提高系统能效），而且通常可对器件工作点进行外部控制，可在照明应用中用于实现调光功能。