Electronics and Telecommunications Research Institute

Ja Yol Lee

Hyun Kyu Yu

Cheon Soo Kim

Sang Heung Lee

Seong Do Kim

Mi Jeong Park

Byung Hun Min

Jong Dae Kim

Bon Tae Koo

Kwi Dong Kim

Mun Yang Park

Chong Ki Kwon

Minjae Lee

Jaehyun Kang

Kyoung Ik Cho

Hae Cheon Kim

Min Jae Lee

Jae Hoon Shim

Jin Yeong Kang

Jang Hong Choi

Seong-Do Kim

Seon Ho Han

Min Uk Heo

Junsoo Ko

Minuk Heo

Seung Hyeub Oh

A phase-locked loop circuit includes a voltage controlled oscillator (VCO) that generates a VCO clock in response to a voltage control signal, a divider that divides the VCO clock to output a division clock, a phase-frequency error detector that receives a reference clock and outputs a first error compensation signal, a sampler that receives the reference clock and oversamples the reference clock at a rising edge or a falling edge to output a sampling clock, a window phase error detector that receives the reference clock and outputs a second error compensation signal, a residue phase error detector that outputs a third error compensation signal, an adder that accumulates the first error compensation signal, the second error compensation signal, and the third error compensation signal to output a final error compensation signal, and a loop filter that converts and output the final error compensation signal into the voltage control signal.

Phase-locked loop circuit and operation method thereof

Provided is frequency-modulated continuous wave generator. The frequency-modulated continuous wave generator includes a ramp signal generator configured to generate an analog ramp signal, a reference signal generator configured to generate a reference signal based on the analog ramp signal, a phase locked loop configured to output a control voltage based on the reference signal, and a voltage-controlled oscillator configured to generate a frequency-modulated continuous wave based on the control voltage. The ramp signal generator is further configured to generate the analog ramp signal based on a feedback signal based on the frequency-modulated continuous wave.

Frequency-modulated continuous wave generator and frequency-modulated continuous wave radar system including the same

Provided is an electronic circuit including a resonant circuit configured to output a resonance voltage having a resonance frequency to a first node, and an oscillation circuit configured to output an oscillation voltage having a level changed according to a first current and a second current based on the resonance voltage received from the first node, wherein the first current is delivered between a first voltage supply terminal and a second node in a first time period, the second current is delivered between the second node and a second voltage supply terminal in a second time period, and a sum of a length of the first time period and a length of the second time period corresponds to the resonance frequency.

Electronic circuit performing push-pull operation and oscillator including the same

Provided is a battery charging system including a battery gauge configured to scale down to indicate a charging capacity of a battery, a charging mode switching unit configured to monitor a charging state of the battery gauge, switch a charging mode according to the charging state of the battery gauge, and charge the battery according to the switched charging mode, and a battery charging control unit configured to receive a charging current input to the battery gauge and a battery charging current input to the battery, and control the charging mode switching unit.

Battery charging system including battery gauge

Provided is a phase locked loop (PLL) that generates an output clock signal corresponding to a reference clock signal, the PLL including a first phase interpolator configured to generate a first interpolator clock signal that has a first time delay from the output clock signal and a second phase interpolator configured to generate a second interpolator clock signal that has a second time delay from the output clock signal. The PLL controls a frequency of the output clock signal based on a multiplexing the first interpolator clock signal and the second interpolator clock signal.

Phase locked loop for reducing fractional spur noise

Provided herein is a digital PLL, which can minimize spurious noise. The digital PLL includes a digital controlled oscillator configured to generate an output oscillation signal in response to a digital code, a phase modulation unit configured to perform phase interpolation on the output oscillation signal in response to a phase control code, a TDC configured to generate an error code using a time difference between a reference clock signal and a modulated clock signal, an error detection unit configured to generate a delay code required to compensate for a phase shift error in response to the phase control code and the error code, a delay unit configured to delay at least one of the reference clock signal and the modulated clock signal and provide a delayed clock signal, and a first decoder configured to control the delay unit in response to the delay code.

Digital phase locked loop and method of driving the same

Provided is a phase locked loop (PLL) that generates an output clock signal corresponding to a reference clock signal. The phase locked loop (PLL) includes a divider configured to divide the output clock signal to generate a divided clock signal, a time-pulse converter configured to generate a time-pulse conversion signal that has a pulse corresponding to a phase difference between the reference clock signal and the divided clock signal, and a digitally controlled oscillator including an LC resonance circuit for generating the output clock signal and configured to control a frequency of the output clock signal that is determined to correspond to a time constant of the LC resonance circuit according to the time-pulse conversion signal, wherein a sustainment time of changed capacitance is continuously controlled according to a change in the phase difference between the reference clock signal and the divided clock signal.

Phase locked loop and operating method thereof

Disclosed is a low-power and high-resolution time-to-digital converter including: a coarse delay cell configured to delay a reference clock by a coarse delay time and output the reference clock; a rising-edge retimer configured to output a rising-edge retimed clock synchronized with the rising-edge of a DCO clock in response to the reference clock; a falling-edge retimer configured to output a falling-edge retimed clock synchronized with the falling-edge of the DCO clock; a first sampler configured to latches output of the coarse delay cell in response to the rising-edge retimed clock and the falling-edge retimed clock; and a pseudo-thermometer code edge detector configured to detect a rising-edge fractional phase error between the reference clock and the rising-edge retimed clock as a coarse phase error from a signal output by the first sampler, and detect a falling-edge fractional phase error between the reference clock and the falling-edge retimed clock.

Low-power high-resolution time-to-digital converter

Disclosed is a fractional digital phase locked loop with an analog phase error compensator. The digital phase locked loop with an analog phase error compensator can reduce excessive power consumption and power noise and transient current noise while increasing phase error detection resolution by performing fractional phase error detection and compensation through the analog phase error compensator.

Fractional digital PLL with analog phase error compensator

An all digital phase-locked loop (ADPLL) includes: a phase counter accumulating a frequency setting word value and the phase of a digitally controlled oscillator (DCO) clock and detecting a fine phase difference between a reference clock and a retimed clock; a phase detector detecting a digital phase error value compensating for a phase difference between the frequency setting word value and the DCO clock according to the fine phase difference to detect a digital phase error value; a digital loop filter filtering the digital phase error value and controlling PLL operational characteristics; a lock detector generating a lock indication signal according an output of the digital loop filter; a digitally controlled oscillator varying the frequency of the DCO clock according to the output from the digital loop filter; and a retimed clock generator generating the retimed clock by retiming the DCO clock at a low frequency.

Time-to-digital converter and all digital phase-locked loop including the same

An apparatus and method for removing an interference signal using a selective frequency phase converter are disclosed. The apparatus for removing an interference signal using a selective frequency phase converter includes: a first phase converter configured to convert a phase of a received RF signal to differentially output first and second signals having a phase difference of 180&#xb0; from each other; a second phase converter configured to receive the first signal and selectively convert the phase of a particular frequency band; a third phase converter configured to receive the second signal and selectively convert the phase of a particular frequency band; a timing controller configured to correct a signal delay time between the output from the second phase converter and that of the third phase converter; and an adder configured to add an output from the second phase converter and an output from the third phase converter, wherein the second and third phase converters phase-convert the first and second signals such that the phases of the signals of the particular frequency bands do not have a phase difference of 180&#xb0; from each other.

Apparatus and method for removing interference signal using selective frequency phase converter

A frequency calibration loop circuit having a pre-set frequency channel word (FCW) command value, a bit inputted to obtain a target frequency in an oscillator and a pre-set minimum division ratio n (n is a constant) of a programmable divider, includes: an oscillator adjusting an oscillation frequency of an oscillation signal according to a control value; a programmable divider dividing the oscillation signal according to a division ratio to output a divided signal; a counter counting the number of clocks of the divided signal for one cycle of a reference signal to output a count value; and a frequency detector obtaining the control value by subtracting the count value from a reference comparison value, wherein the reference comparison value is obtained by dividing a Frequency Channel Word (FCW) command value by a minimum division ratio of the programmable divider.

Frequency calibration loop circuit

There is provided a digital lock detector and a frequency synthesizer using the same. The digital lock detector includes a comparator unit receiving a plurality of control bits, and generating a bit signal to notice a lock condition of the plurality of control bits; a delay cell block generating a plurality of delay signals based on the bit signal, and outputting a clock signal by combining the bit signal and the plurality of delay signals; and a detection unit detecting a shift time of the clock signal, and generating a lock indication signal according to the detection result.

Frequency synthesizer including a digital lock detector

An apparatus for compensating for an error of a time-to-digital converter (TDC) is disclosed to receive a delay phase from a phase detector including the TDC and a phase error including a TDC error and compensate for the TDC error to have a time resolution higher by N times (N is a natural number). The apparatus includes: a fragmenting and multiplying unit fragmenting the delay phase by N times (N is a natural number) to generate first to (N&#x2212;1)th fragmented delay phases; an adding unit adding each of the first to the (N&#x2212;1)th fragmented delay phases to the phase error to generate first to (N&#x2212;1)th phase errors; and a comparison unit acquiring a phase error compensation value nearest to an actual phase error from the phase error and the first to (N&#x2212;1)th phase errors.

Apparatus for compensating for error of time-to-digital converter

A digital proportional integral loop filter is provided. A first proportional amplification unit multiplies a phase error value by a first proportional loop gain, and a first integral amplification unit multiplies a phase error accumulation value by a first integral loop gain. A second proportional amplification unit multiplies the phase error value by a second proportional loop gain, and a second integral amplification unit multiplies the phase error accumulation value by a second integral loop gain. A first offset value generation unit generates a first offset value by subtracting the second proportional loop gain from the first proportional loop gain and multiplying a resulting value by a phase error average value, and a second offset value generation unit generates a second offset value by subtracting the second integral loop gain from the first integral loop gain and multiplying a resulting value by a phase error accumulation average value.

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Daejeon, South Korea

Ja Yol Lee