Auto frequency calibrator, method thereof and frequency synthesizer using it
AssigneeSamsung Electro-Mechanics Co., Ltd.
InventorsYoo Hwan KIM, Yoo Sam Na, Byeong Hak Jo
Life of this patent
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Abstract
The present invention relates to and auto frequency calibrator, a method thereof, and a frequency synthesizer using it. The auto frequency calibrator includes a capacitor bank selector that is operated as an open loop and compares a frequency signal having integer-divided reference frequency with the reference frequency signal to select a capacitor bank corresponding to an output frequency; and a capacitor bank controller that is operated as a closed loop when the capacitor bank is selected and compares the output voltage corresponding to the output frequency with a preset voltage range to control the capacitor bank selected in the capacitor bank selector.
Claims15
An auto frequency calibrator, comprising:
- a capacitor bank selector that is operated as an open loop and compares a frequency signal having integer-divided reference frequency with the reference frequency signal to select a capacitor bank corresponding to an output frequency;
- and
- a capacitor bank controller that is operated as a closed loop when the capacitor bank is selected and compares the output voltage corresponding to the output frequency with a preset voltage range to control the capacitor bank selected in the capacitor bank selector.
A frequency synthesizer, comprising:
- an auto frequency calibrator including a capacitor bank selector that is operated as an open loop and compares a frequency signal having an integer-divided frequency signal with the reference frequency signal to select a capacitor bank corresponding to an output frequency and a capacitor bank controller that forms a closed loop when the capacitor bank is selected and compares the output voltage corresponding to the output frequency with a preset voltage range to control the capacitor bank selected in the capacitor bank selector;
- and
- a loop switching element that forms the closed loop when the capacitor bank is selected in the capacitor bank selector to detect the output voltage corresponding to the output frequency.
A method of automatically calibrating a frequency selecting a capacitor bank operated as an open loop according to an integer-divided frequency signal and then controlling the capacitor bank operated as a closed loop by measuring an output voltage, comprising:
- selecting the capacitor bank that is operated as the open loop and corresponds to an output frequency by comparing a reference frequency signal with an integer-divided frequency signal;
- and
- controlling the capacitor bank selected in the capacitor bank selector by forming the closed loop when the capacitor bank is selected and comparing the output voltage corresponding to the output frequency with a preset voltage range.
Dependencies are inferred from the claim text.