Patent ID: 9232576
Filing Date: 2016-01-05
CPC Classification: H05B

Claim Text:
1. An LED direct driver under low input voltage operation including at least an anti-flicker circuit and a current source, and the anti-flicker circuit comprising: a first path having a first resistor and a first diode connected in series; a second path being parallel to the first path, and having a second resistor and second diode connected in series, wherein directions of the first diode and the second diode are reversed; a filter capacitor being connected to the first path, the second path and the current source of the LED direct driver, and discharging current via the first path; and a comparator having a reference voltage, which charges the filter capacitor via the second path to increase voltage of the current source when a voltage of the current source is below the reference voltage, wherein an RC time constant of the first path and the filter capacitor in combination with the second path and the filter capacitor is slower than a period of the flicker.