TV tuners and methods thereof are provided. A TV tuner includes a first frequency converting circuit, a second frequency converting circuit, and a demodulator. The first frequency converting circuit, switchable between a first operating mode and a second operating mode, receives an RF signal and outputs a converted signal by performing high-side injection on the RF signal in the first operating mode and performing frequency addition on the RF signal in the second operating mode. The second frequency converting circuit performs a down conversion on the converted signal from the first frequency converting circuit to obtain an intermediate frequency signal. The demodulator demodulates the intermediate frequency signal and outputs a baseband frequency signal comprising video and audio signals.