DIGITAL TUNING CIRCUIT OF GM-C FILTER

摘要

A digital tuning circuit of a GM-C filter which decreases the electricity by using one GM cell is provided to tune Gm by using direct current without using clock signal in a gm tuning mode. A Gm cell circuit unit(200) operates in a Gm tuning mode. The Gm tuning is performed according to the Gm tuning coefficient. A D/A converter(300) varies a second reference voltage according to DAC tuning coefficient and converts the second reference voltage into a third voltage. An error detecting unit controls the capacitor tuning by using the first voltage between the third voltage and the first voltage in a capacitor tuning mode. The error detecting unit controls the Gm tuning by using the Gm tuning coefficient corresponding to a second voltage in Gm tuning mode.