Patent ID: 6542725
Filing Date: 2003-04-01
Classification: H04N

Abstract:
Amplifier circuit arrangement for alternatively processing a digital signal or an analog signal comprising:an input terminal for receiving a digital signal or an analog signal, alternatively, a first channel for processing the digital signal, a second channel for processing the analog signal, a first filter connected between said input terminal and an input terminal of said first channel, an output terminal of said first filter being connected to an input terminal of a second filter so that said second filter receives signals without frequency conversion between said first filter and said second filter, said second filter having an output terminal being connected to an input terminal of said second channel, with the result that for reception of a digital signal only said first filter is used whereas for reception of the analog signal both filters are arranged in cascade and the selectivity characteristics of said second filter are improved by said first filter, said arrangement further comprising switching means having a first input terminal connected to the output terminal of said first filter and a second input terminal connected to the output terminal of said second filter and an output terminal connected to an input terminal of a signal path for further processing said digital signal or said analog signal, respectively, said switching means being controlled by a control voltage in such a way that the input of the signal path for further processing is connected to the output of said first filter during reception of digital signals and to the output of said second filter during reception of analog signals.