Phase locked loop with power supply control

A phase locked loop (PLL) comprising:

• a phase frequency detector powered by a first analog supply voltage;
• a charge pump coupled to the phase frequency detector, the charge pump powered by a second analog supply voltage, different from the first analog supply voltage;
• a voltage controlled oscillator (VCO) coupled to the charge pump, the VCO powered by a third analog supply voltage, different from the first analog supply voltage and different from the second analog supply voltage, wherein a frequency of the VCO is controlled by a control voltage;
• and
• a supply voltage provider having a first circuit node coupled to a fourth analog supply voltage, the supply voltage provider comprising:
• a first resistor having a first terminal coupled to the first circuit node and a second terminal coupled to a second circuit node;
• a second resistor having a first terminal coupled to the second circuit node and a second terminal coupled to a third circuit node;
• a third resistor having a first terminal coupled to the third circuit node and a second terminal coupled to ground;
• and
• a first capacitor having a first terminal coupled to the third circuit node and a second terminal coupled to ground, wherein the first circuit node provides the first analog supply voltage, the second circuit node provides the second analog supply voltage, and the third circuit node provides the third analog supply voltage.

In a phase locked loop (PLL), a method comprising:

• providing a first analog supply voltage from a first circuit node of a plurality of series-connected resistors to a phase frequency detector of the PLL;
• providing a second analog supply voltage from a second circuit node of the plurality of series-connected resistors to a charge pump of the PLL;
• providing a third analog supply voltage from a third circuit node of the plurality of series-connected resistors to a VCO of the PLL, wherein each of the first, second, and third analog supply voltages are different;
• providing an input control voltage to the VCO to control a frequency of the VCO, wherein the input control voltage is provided based on an output control voltage of the charge pump;
• and
• drawing a variable current from the third circuit node in response to the input control voltage such that the third analog supply voltage remains at a substantially constant predetermined voltage level.