| 摘要 |
A device for protecting a low voltage LED direct driver comprises a rectifying stage, a major string, a minor string, a high voltage NFE , a pull-up resistor, and an avalanche unit (zener diode or equivalent component). The high voltage NFET has a gate, a drain and a source. The drain of the high voltage NFET is connected to a bottom end of the major string , the source of the high voltage NFET is connected to a top of the minor string. The pull-up resistor is connected between the gate of the high voltage NFET. The avalanche unit has a first end and a second end. The first end of the avalanche unit is connected to the gate of the high voltage NFET and the pull-up resistor. High voltage NFET is placed just above the low voltage LED direct driver and biased, which provides excellent voltage protection for the low voltage LED direct driver. |
| 主权项 |
1. A device for protecting a low voltage LED direct driver comprising:
a rectifying stage rectifying an AC input voltage to a pulsating DC voltage; a major string, a top end of the major string being connected to the rectifying stage; a minor string being connected to the low voltage LED direct driver and a current source integrated inside the low voltage LED direct driver; a high voltage NFET, a drain of the high voltage NFET being connected to a bottom end of the major string, and a source of the high voltage NFET being connected to a top of the minor string; a pull-up resistor connected between a gate of the high voltage NFET; and an avalanche unit (commonly known as a zener diode), a first end of the avalanche unit being connected to the gate of the high voltage NFET and the pull-up resistor, and a second end of the avalanche unit being connected to the current source of the low voltage LED direct driver. |
