| 摘要 |
PURPOSE:To obtain a small-sized, low-power-consumption tuning circuit by incorporating a timer circuit, a semiconductor variable capacity element, and a capacity-value control circuit for said element in an MOS integrated circuit. CONSTITUTION:An MOS integrated circuit 1 consists of a timer circuit 3, a capacity-value control circuit 4, and a semiconductor variable capacity element 5. The circuit 1 is equipped with a radio circuit part 2, an operation part 6, and a display part 7. The capacity-value control circuit 4 is brought under the control of the operation part 6 to generate a pulse signal sequence. This pulse sequence is applied to the element 5 to set an optional capacity value. This capacitance, the local oscillation coil of the radio circuit part 2, and the coil of an antenna 8 constitute a turning circuit to select an optional channel. |
