Patent ID: 6388510
Filing Date: 2002-05-14
Classification: H03H

Abstract:
A transconductance-capacitance filter system comprising:a transconductance-capacitance filter circuit including a transconductance amplifier and a capacitor; an adjusting circuit including an oscillator containing a transconductance amplifier having the same structure as that of the transconductance amplifier of said transconductance-capacitance filter circuit, said adjusting circuit producing a digital adjusting value used to adjust the transconductance of the transconductance amplifier of said oscillator based upon an oscillation signal outputted from said oscillator; a register for holding said digital adjusting value supplied from said adjusting circuit; and a D/A converter for converting said digital adjusting value held in said register into an analog adjusting value which is used to adjust the transconductance of the transconductance amplifier of said transconductance-capacitance filter circuit, wherein said adjusting circuit is operated in an intermittent manner.