Patent ID: 8120436

Claim:
A system for generating an oscillating signal, the system comprising: a fully differential transconductance amplifier comprising a first transistor and a second transistor; only one feedback loop coupled to each output terminal of the fully differential transconductance amplifier such that each of the first transistor and the second transistor are coupled to two capacitors, the feedback loop comprising: a low pass filter configured to receive a signal from one output terminal of the fully differential transconductance amplifier, wherein the low pass filter comprises a varactor coupled, in parallel, to a resistor; and a high pass filter configured to: receive the output of the low pass filter; and output a signal to the input of the fully differential transconductance amplifier; wherein the high pass filter comprises a variable resistor coupled, in series, to a capacitor; a third transistor operable to bias the fully differential transconductance amplifier; a set of resistors, not comprised by the low pass or high pass filters, coupled to the fully differential transconductance amplifier operable to detect a common-mode voltage from the differential outputs of the transconductance amplifier.