| abstract |
A frequency-voltage converting circuit 13 is composed of a switch unit including switches SW 1 and SW 2 , electrostatic capacitive elements C and C 10 to C 13 , and switches CSW 0 to CSW 3 . The electrostatic capacitive elements C 10 to C 13 are composed of elements having mutually different absolute values of capacitance and are provided so as to cover a frequency range intended by a designer. The electrostatic capacitance values are weighted by, for example, 2. The electrostatic capacitive elements C 11 to C 13 are selected by, for example, the switches CSW 0 to CSW 3 based on 4-bit frequency adjustment control signals SELC 0 to SELC 3 , thereby carrying out frequency switching. |