Fully differential adaptive bandwidth PLL with differential supply regulation
AssigneeConexant Systems, Inc.
InventorChandrashekar Reddy
Life of this patent
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Abstract
Provided is a fully differential adaptive bandwidth phase locked loop with differential supply regulation. One fully differential phase locked loop includes a differential active loop filter and regulator coupled to an output of a differential charge pump, a differential voltage-controlled oscillator coupled to differential control voltages developed by the differential active loop filter and regulator, and a bias circuit coupled to the differential control voltages and providing a bias current to the differential charge pump.
Claims20
A fully differential adaptive bandwidth phase locked loop (PLL) with differential supply regulation, the PLL comprising:
- a differential active loop filter and regulator (DALFR) coupled to an output of a differential charge pump;
- a differential voltage-controlled oscillator (DVCO) coupled to differential control voltages developed by the DALFR;
- a bias circuit coupled to the differential control voltages and providing a bias current to the differential charge pump.
A differential active loop filter and regulator (DALFR) for a fully differential adaptive bandwidth phase locked loop (PLL) with differential supply regulation, the DALFR comprising:
- an active loop filter amplifier/regulator (ALFA/R);
- a plurality of capacitors and resistors configured to form first and second feedback networks for respective first and second differential outputs of the ALFA/R;
- the ALFA/R and the plurality of capacitors and resistors developing differential control voltages for the PLL.
A bias circuit for a fully differential adaptive bandwidth phase locked loop (PLL) with differential supply regulation, the bias circuit comprising:
- a first transistor coupled to differential control voltages of the PLL;
- a second transistor in series with the first transistor and coupled to a third transistor;
- the third transistor being configured to provide a bias current for the PLL that is derived from the differential control voltages of the PLL.
Dependencies are inferred from the claim text.