Patent ID: 7012487

Claim:
An integrated circuit comprising: a voltage controlled oscillator comprising: a first gm cell; a second gm cell having a noninverting input coupled to a noninverting output of the first gm cell, an inverting input coupled to an inverting output of the first gm cell, a noninverting output coupled to an inverting input of the first gm cell, and an inverting output coupled to a noninverting input of the first gm cell; a first capacitance coupled between the noninverting output and inverting output of the first gm cell; a second capacitance coupled between the noninverting output and inverting output of the second gm cell; and a first filter coupled to the voltage controlled oscillator comprising: a third gm cell, wherein the first gm cell, the second gm cell, and the third gm cell each comprise a variable resistance, the variable resistance comprising a first native MOS device.