Patent ID: 9030106
Filing Date: 2015-05-12
Classification: H05B

Abstract:
1. A driving circuit for a LED backlight module, comprising: a load; a constant current source connected to the load for outputting a stable constant current to the load; a comparing module connected to the constant current source; a brightness adjusting module connected to the comparing module and the load for adjusting a brightness of the load, the brightness adjusting module comprising at least one MOS transistor, a gate of each MOS transistor being connected to a micro control unit or a system on chip as an input terminal, a drain thereof being connected to the comparing module, and a source thereof being grounded via a resistor; a current detector connected to the source of the corresponding MOS transistor for detecting a current of the brightness adjusting module and generating a detecting result; and a reference voltage adjusting module connected to the current detector for receiving the detecting result and connected to the comparing module for supplying an adjustable reference voltage to the comparing module, the reference voltage adjusting module comprising four voltage scales respectively corresponding to the reference voltages of 0.3V, 0.4V, 0.6V, and 0.8V, and the reference voltage choosing the corresponding voltage scale according to the detecting result and outputting the reference voltage corresponding to the chosen voltage scale to the comparing module.