A stage for a ring oscillator, the stage including a first p-channel transistor having a gate defining a control node, having a source adapted to be coupled to a supply voltage, and having a drain; a second p-channel transistor having a gate coupled to the control node, having a source coupled to the...http://www.google.de/patents/US6198357?utm_source=gb-gplus-sharePatent US6198357 - Stage having controlled variable resistance load circuit for use in voltage controlled ring oscillator
