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US 2010/0073048 A1Published application
Phase locked loop and calibration method
AssigneeMediatek Inc.
InventorsLing-Wei KE, Tai-Yuan YU, Hsin-Hung CHEN, Tser-Yu LIN
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AssigneeMediatek Inc.
InventorsLing-Wei KE, Tai-Yuan YU, Hsin-Hung CHEN, Tser-Yu LIN
Estimating the term…
A phase locked loop (PLL) directly uses a charge pump and loop filter therein for fast and low-costly calibration. The PLL comprises a charge pump, a loop filter, a voltage comparator, a counting device, and a calibration device. The loop filter comprises a voltage storage device coupled to the charge pump for charging by the charge pump, wherein the voltage storage device comprises a variable impedance. The voltage comparator is coupled to a voltage reference and to the voltage storage device for comparing a voltage of the storage device and a voltage of the voltage reference. The counting device is coupled to the voltage comparator to measure the charge time required for the voltage of the voltage storage device to substantially equal to the voltage of the voltage reference. The calibration device adjusts the variable impedance to adjust the time measured by the counting device to a desired time.
A phase locked loop, comprising:
A method for calibrating a time constant for an electronic circuit comprising a phased locked loop which comprises a charge pump and a loop filter, the method comprising:
A method for calibrating a time constant for an integrated circuit comprising a phased locked loop, comprising:
Dependencies are inferred from the claim text.