Patent ID: 8742788
Filing Date: 2014-06-03
Classification: H03F

Abstract:
1. A common mode control circuit operable to generate a control signal indicative of a common mode signal in first and second signals of a differential signal pair, the common mode control circuit comprising: a first control input for the first signal; a second control input for the second signal; a control output for the control signal; a capacitive element comprising a first capacitive element, a second capacitive element and a third capacitive element; a first charge controller operative to vary charge applied to the capacitive element dependent on polarity of the first and second signals with respect to a threshold, the first charge controller comprising wherein a first terminal of the third capacitive element is coupled to the control output and a second terminal of the third capacitive element is coupled to a reference voltage; and wherein first charge controller is operable to maintain a direction of flow of the charge in response to the first and second signals both switching polarity simultaneously from opposite polarities.