| 摘要 |
Provided are a single-string overpower protection device and a light source driving circuit in a display. The device comprises a voltage detecting unit, an integrating unit, a comparing unit and a locking unit. The input terminal of the voltage detecting unit is connected to the two terminals of a resistor in a single-string light bar circuit to obtain terminal voltages on these terminals; the input terminal of the integrating unit is connected to the output terminal of the voltage detecting unit, and the integrating unit is used for performing integral transformation on the obtained terminal voltages; the comparing unit is connected to the output terminal of the integrating unit and used for comparing the voltages resulting from integral transformation with a reference voltage, in order to output a valid over-voltage signal in the case that the voltages resulting from integral transformation are higher than the reference voltage; the locking unit is connected with the comparing unit and used for locking an output standby signal according to the valid over-voltage signal. With the protection device, the problem that the entire backlight module is negatively affected by overheat arising from the excessively high current on a single-string light bar can be avoided, thus better protecting the LCD (Liquid Crystal Display). |
