Systems and methods for calibrating the loop bandwidth of a phase-locked loop (PLL)
AssigneeQUALCOMM Incorporated
InventorChan Hong Park
Life of this patent
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Abstract
A method for calibrating the loop bandwidth of a phase-locked loop (PLL) is described. At least one resistor in the PLL filter is tuned in accordance with the frequency of an input reference signal. One or more capacitors in the PLL filter are tuned in accordance with the frequency of the input reference signal. Output pulses of one or more voltage controlled oscillators (VCO) are counted. A first charge pump current associated with a target loop bandwidth is counted in accordance with the counted output pulses. A programmable charge pump current is tuned to the calculated first charge pump current.
Claims35
A method for calibrating the loop bandwidth of a phase-locked loop (PLL), comprising:
- tuning at least one resistor in the PLL in accordance with the frequency of an input reference signal;
- tuning one or more capacitors in the PLL in accordance with the frequency of the input reference signal;
- counting variable output pulses of one or more voltage controlled oscillators (VCO), counting lower control voltages of the variable output pulses, and counting higher control voltages of the variable output pulses;
- calculating a first charge pump current associated with a target loop bandwidth in accordance with the counted variable output pulses, the counted lower control voltages and the counted higher control voltages;
- and
- tuning a programmable charge pump current to the calculated first charge pump current.
A circuit for calibrating the loop bandwidth of a phase-locked loop (PLL), the circuit comprising:
- at least one resistor, wherein the at least one resistor is tuned in accordance with the frequency of a input reference signal;
- one or more capacitors, wherein the one or more capacitors are tuned in accordance with the frequency of the input reference signal;
- a voltage controlled oscillator (VCO) counter, wherein the VCO counter counts variable output pulses of one or more voltage controlled oscillators, lower control voltages of the variable output pulses, and higher control voltages of the variable output pulses;
- a digital signal processor (DSP), wherein the DSP calculates a first charge pump current associated with a target loop bandwidth in accordance with the counted variable output pulses, the counted lower control voltages and the counted higher control voltages;
- and
- wherein the DSP tunes a programmable charge pump current to the calculated first charge pump current.
An apparatus for calibrating the loop bandwidth of a phase-locked loop (PLL), comprising:
- means for tuning at least one resistor in the PLL in accordance with the frequency of an input reference signal;
- means for tuning one or more capacitors in the PLL in accordance with the frequency of the input reference signal;
- means for counting variable output pulses of one or more voltage controlled oscillators (VCO), lower control voltages of the variable output pulses, and higher control voltages of the variable output pulses;
- means for calculating a first charge pump current associated with a target loop bandwidth in accordance with the counted variable output pulses, the counted lower control voltages and the counted higher control voltages;
- and
- means for tuning a programmable charge pump current to the calculated first charge pump current.
A non-transitory storage medium having processor-executable instructions stored thereon, the instructions being configured to cause a processor to perform operations for calibrating the loop bandwidth of a phase-locked loop (PLL), the operations comprising:
- tuning one or more resistors in the PLL in accordance with the frequency of an input reference signal;
- tuning one or more capacitors in the PLL in accordance with the frequency of the input reference signal;
- counting variable output pulses of one or more voltage controlled oscillators (VCO), lower control voltages of the variable output pulses, and higher control voltages of the variable output pulses;
- calculating a first charge pump current associated with a target loop bandwidth in accordance with the counted variable output pulses, the counted lower control voltages, and the counted higher control voltages;
- and
- tuning a programmable charge pump current to the calculated first charge pump current.
Dependencies are inferred from the claim text.