ADJUSTING THE MAGNITUDE OF A CAPACITANCE OF A DIGITALLY CONTROLLED CIRCUIT

摘要

An apparatus comprises a digitally controlled circuit having a variable capacitance and a controller configured to adjust a magnitude of the variable capacitance of the digitally controlled circuit. The digitally controlled circuit comprises a plurality of gain elements, the plurality of gain elements comprising one or more positive voltage-to-frequency gain elements and one or more negative voltage-to-frequency gain elements. The controller is configured to adjust the magnitude of the capacitance by adjusting the gain provided by respective ones of the gain elements in an alternating sequence of the positive voltage-to-frequency gain elements and the negative voltage-to-frequency gain elements.

主权项

1. A method comprising:
generating a control voltage for a digitally controlled circuit having a variable capacitance, the digitally controlled circuit comprising a plurality of gain elements; providing control signals to the plurality of gain elements by applying the control voltage to a first one of the plurality of gain elements and applying a fixed high voltage or a fixed low voltage to other ones of the plurality of gain elements; and adjusting a magnitude of the variable capacitance of the digitally controlled circuit by adjusting the control voltage applied to the first gain element and, if the first gain element is saturated, adjusting the control signals to apply the fixed high voltage or the fixed low voltage to the first gain element and to apply the control voltage to a second one of the plurality of gain elements; wherein the first gain element comprises one of a positive voltage-to-frequency gain element and a negative voltage-to-frequency gain element and the second gain element comprises the other one of a positive voltage-to-frequency gain element and a negative voltage-to-frequency gain element.