| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To make a GmC value constant and to simultaneously provide low power consumption about a cut-off frequency adjusting method, a GmC filter circuit and a semiconductor device. <P>SOLUTION: In the cut-off frequency adjusting method for adjusting a cut-off frequency of a GmC filter circuit provided with an OTA circuit controllable a Gm value and a capacitor, a Gm value of the OTA circuit is detected on the basis of the voltage of the capacitor for charging charge with an output of the OTA circuit, and the Gm value of the OTA circuit is controlled to be constant on the basis of the detected Gm value so as to thereby make the cut-off frequency of the GmC filter circuit a desired value. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
