A power management and control module adapted for a liquid crystal display device includes a boost-type DC/DC topology circuit, a LED dimming control circuit and a multiplexer. The boost-type DC/DC topology circuit has a voltage output terminal electrically connected with a logic high power supply terminal of a gate driving circuit and a power supply terminal of a LED backlight source. The LED dimming control circuit is electrically connected with the LED backlight source for dimming operation. A first and second data input terminals of the multiplexer are electrically connected to the voltage output terminal through a first and second feedback networks respectively. The LED backlight source is electrically connected in the second feedback network. A data output terminal of the multiplexer is electrically connected to the boost-type DC/DC topology circuit and alternatively communicated with the first or second data input terminal to provide a feedback input voltage.