| 摘要 |
A high efficiency LED driver circuit utilizing a capacitor to regulate the L ED driving current. The voltage across the capacitor is monitored to maintain a preselected low threshold voltage on the capacitor, which determines the LED optical emission intensity. The capacito r provides the LED driver current by discharging through the LED during transmission intervals, and the power supply for the device is used only to maintain the capacitor charge level. The LED driver circuit of the invention accordingly operates at high efficiency with low power consumption . The LED driver current can be regulated by changing the low and high threshold voltages of the capacitor pump controller, to thus control the optical intensity of the LED.
|
