| 摘要 |
A drive circuit drives LED groups each of which has a plurality of LEDs connected in series. The drive circuit includes nMOSFETs which drive the LED groups, current regulating circuits which determine drain currents of the nMOSFETs, and subtracters which control the current regulating circuits to keep the sum of the current values of adjacent two nMOSFETs constant. The LEDs can be switched on/off efficiently even when there are differences between forward voltages of the LEDs.
|
