230VAC Off-Line LED Driver
Created: Dec 05, 2016
No description available.
Typical LED drivers are used in applications that need constant regulation of power to an output LEDs. These LEDs are basically powered by a DC voltage source. The reference design is an evaluation board of an off-line LED driver that utilizes HV98101, which is a high-power factor, buck-boost controller targeted at general LED lighting products, such as LED lamps and LED lighting fixtures with a maximum power rating of about 15W. This IC is specifically designed to work from a nominal 230VAC input voltage.
The evaluation board is designed to control the output LED current while maintaining high-input power factor (PF) and low total harmonic distortion (THD). The HV98101 can vary both on-time and switching period at the same time in one cycle, which cause to force the average input current to be proportional to the input voltage. The board can be powered by using a power supply, which can provide a 1A current and has a voltage range of 195VAC to 280VAC at pin W1. Using external resistor R1 and a fixed internal reference, the output current for the LED of the board is determined. The driver incorporates valley switching (quasi-resonant switching), a technique for reducing switching loss at the turn-on event of the buck-boost converter FET. The HV98101 IC uses a unique control scheme to achieve high-power factor and low THD simultaneously under all line and load conditions, while maximizing efficiency by utilizing valley switching.
The HV98101 can be applied to specific applications like LED lamps and LED lighting fixtures. It can be also be used in applications with low-output voltage provided that a coupled inductor is used.