| 摘要 |
PURPOSE: A circuit for compensating for frequency characteristic of a Gm-C filter is provided to compensate for a variation in the frequency characteristic of the Gm-C due to a process variation in fabrication of a semiconductor chip including the Gm-C filter. CONSTITUTION: In a Gm-C filter(30) configured using a resistor having wider variation in its fabrication process, when the frequency characteristic of the Gm-C filter is changed due to the process variation, a control current(Ir) corresponding to the variation in the frequency characteristic is generated and Gm value of the Gm-C filter is controlled depending on the control current, thereby minimizing the variation in the frequency characteristic of the Gm-C filter. A circuit for compensating for the frequency characteristic of the Gm-C filter includes a first control resistor(R1) having very low process variation, a second control resistor(R2) having the same process variation as that of the resistor used for the Gm-C filter, a first current source for supplying current to the first and second control resistors, and a second current source(I2) for generating the control current. |
