Abstract: A tuner at least comprises a filter, a low noise amplifier, a mixer, a local oscillator, a frequency selector and a power management module, and the tuner is characterized in that the power management module includes a power detection means which has a first terminal connected to an input terminal of the tuner for detecting the power level of the input terminal and a second terminal connected to the low noise amplifier, and a power management means which has a first terminal connected to a third terminal of the power detection means for reducing the power consumption of the tuner by means of the power management module which makes the tuner operative under the optimum condition for power consumption.