| 摘要 |
A cutoff frequency adjusting method adjusts a cutoff frequency of a GmC filter circuit which has a capacitor and an Operational Transconductance Amplifier (OTA) circuit with a controllable Gm value. A Gm value of the OTA circuit is detected based on a voltage of the capacitor which is charged by an output of the OTA circuit, and a cutoff frequency of the GmC circuit is set to a desired value by controlling the Gm value of the OTA circuit constant based on the detected Gm value.
|
