Browsing by Author "Chen Wei-Zen"

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Digital fast-locking frequency synthesizer
(2011-07-12)
Chen Wei-Zen
;
Yang Song-Yu
A digital PLL frequency synthesizer characterized by fast-locking and low-jitters is presented. The PLL comprises a phase detector, a controllable oscillator, a loop filter having an automatically-adjusted loop gain, a feedback phase integration circuit, and a reference phase integration circuit. Fast-locking is achieved by dynamically adjusting forward-path gain and integral-path gain according to the output of the phase detector and the output of the integral-path during phase tracking. A skew-compensated counter circuit is proposed, which incorporates an asynchronous counter, a data register and a sample phase generator and features high-speed and low-power operation.
Phase-locked loop
(2014-08-19)
Chen Wei-Zen
;
Wang Yan-Ting
The PLL includes a voltage-controlled oscillator (VCO), a frequency down conversion circuit, a phase-frequency detector (PFD), and an adjusting circuit. The VCO is configured to generate an output clock signal. The frequency down conversion circuit is configured to receive the output clock signal and an auxiliary clock signal, and to mix the output clock signal and the auxiliary clock signal to generate a feedback clock signal. By detecting the strength of the feedback clock signal, it provides an auxiliary signal to adjust the frequency of the output clock signal. The PFD is configured to compare the frequencies and the phases of the feedback clock signal and a reference clock signal to generate an adjusting signal. The adjusting circuit is configured to receive the adjusting signal, and to adjust the frequency of the output clock signal generated by the VCO according to the adjusting signal.
PHASE-LOCKED LOOP WITH LOOP GAIN CALIBRATION, GAIN MEASUREMENT METHOD, GAIN CALIBRATION METHOD AND JITTER MEASUREMENT METHOD FOR PHASE-LOCKED LOOP
(2014-03-20)
Chen Wei-Zen
;
Chuang Shu-Chin
The invention provides a phase-locked loop with loop gain calibration and methods for measuring an oscillator gain, gain calibration and jitter measurement for a phase-locked loop. The method for measuring an oscillator gain of a phase-locked loop includes the steps of providing a varying code at an input end of the oscillator; outputting excess reference phase information by a reference phase integral path and outputting excess feedback phase information based on the varying code by a feedback phase integral path; and obtaining an estimated gain information of the oscillator based on the excess reference phase information and the excess feedback phase information.
Phase-locked loop with loop gain calibration, gain measurement method, gain calibration method and jitter measurement method for phase-locked loop
(2014-10-14)
Chen Wei-Zen
;
Chuang Shu-Chin
The invention provides a phase-locked loop with loop gain calibration and methods for measuring an oscillator gain, gain calibration and jitter measurement for a phase-locked loop. The method for measuring an oscillator gain of a phase-locked loop includes the steps of providing a varying code at an input end of the oscillator; outputting excess reference phase information by a reference phase integral path and outputting excess feedback phase information based on the varying code by a feedback phase integral path; and obtaining an estimated gain information of the oscillator based on the excess reference phase information and the excess feedback phase information.
Voltage-controlled oscillator
(2011-12-06)
Chen Wei-Zen
;
Wu Chung-Yu
;
Yu Chi-Yao
A voltage-controlled oscillator comprises a variable inductor, a negative impedance circuit, an operating voltage source and a ground point. The variable inductor comprises a transformer and a transistor switch, the transformer comprising a primary side coil and a secondary side coil, the primary side coil comprising a first coil and a second coil, and the secondary side coil comprising a third coil and a fourth coil. The transistor switch is connected in parallel with the primary side coil to adjust an inductance value of the variable inductor based on a gate voltage. The negative impedance circuit is connected in parallel with the secondary side coil to compensate the power consumption of the voltage-controlled oscillator during oscillation. The operating voltage source is electrically connected between the third coil and the fourth coil, and the ground point is electrically connected between the first coil and the second coil.