Abstract: A LED driving circuit and a backlight module using the same are disclosed. The LED driving circuit comprises a LED module and a current controlling unit. The LED module has a plurality of the LED strings, each having a driving terminal. The current controlling unit has a plurality of current balancing terminal coupled to the driving terminal, for balancing the currents flowing through the LED strings. The current controlling unit receives a mode switch signal, controls the amount of the currents of the LED strings about a first current value when the mode switch signal represent a first mode, and controls the amount of the currents of the LED strings about a second current value when the mode switch signal represent a second mode.

Abstract: A bias voltage is compared with a voltage difference in a detecting element according to the present invention. A bias voltage unit is coupled to the detecting element, so that they have a common voltage level to avoid noises when the circuit is operating. Accordingly, the erroneous detection caused by the noise interference can be avoided. Hence, a detecting element with a low resistance, such as an MOEFET, can be used in the present invention to decrease power consumption arisen from current detection and to further increase conversion efficiency.

Abstract: A voltage detection enabling circuit is disclosed. The voltage detection enabling circuit includes a reference voltage generating unit, an enabling protection unit, and an enabling judgment unit. The reference voltage generating unit is coupled to a driving voltage, and generates a reference voltage signal. The enabling protection unit receives the reference voltage signal and outputs an enabling judgment signal when the reference voltage signal is higher than a voltage parameter. Particularly, the voltage parameter is a component parameter of an electronic component. Then the enabling judgment unit determines whether an enabling signal is generated or not according to the enabling judgment signal and the driving voltage.

Abstract: The present invention uses a discharge path to release the power stored in an output capacitor of a converting circuit when the time interval between two adjacent switching thereof is too long and may generate noises whose frequencies can be sensed by human ears. Hence, the present invention can keep the operating frequency of the converting circuit higher than a predetermined frequency and reduce the audio noise of the converting circuit.