| 摘要 |
PROBLEM TO BE SOLVED: To easily configure a television tuner by using an integrated circuit with a built-in variable capacitative element, which operates at low voltage without using a varactor diode needing high voltage or a DC-DC converter for creating high voltage. SOLUTION: This television tuner is provided with a high frequency tuning circuit 1, a high frequency amplifier 2, a mixer 4 and an oscillator. The high frequency tuning circuit 1 consists of an inductance element L and a plurality of capacitative elements C0 to Cn, and one or more capacitative elements are selected and connected to the inductance element L in parallel. At least, an oscillating part 5 consists of a plurality of oscillators 5a to 5n configured in an integrated circuit 11. In the integrated circuit 11, variable capacitative elements 5a2 to 5a2 for changing the frequency of a local oscillation signal are configured for the oscillators 5a to 5n, respectively, the respective oscillators 5a to 5n are made to correspond to each group for dividing a receiving frequency band into a plurality of groups, and the respective oscillators 5a to 5n are oscillated corresponding to a television signal in each of the groups. COPYRIGHT: (C)2004,JPO |
