Patent ID: 7468629
Filing Date: 2008-12-23
Classification: H03H

Abstract:
1. A transconductance tuning circuit comprising: a transconductor cell, capable of receiving an input signal and providing a corresponding driving signal, the transconductor cell having a transconductance being changeable according to a control signal, the input signal being a square wave voltage signal having a constant frequency; a capacitor module having an input being coupled to the capacitor module for charging or discharging according to the driving signal to thereby provide a corresponding output signal; and an amplitude detecting feedback circuit having an input being coupled to the output signal of the capacitor module, the amplitude detecting feedback circuit for tuning a value of the control signal according to an amplitude level of the output signal and utilizing feedback of the control signal to the transconductor cell to lock an amplitude of the output signal within a predetermined range; wherein the amplitude detecting feedback circuit includes: