H03L7/199

Digital phase locked loop circuit adjusting digital gain to maintain loop bandwidth uniformly

A digital phase locked loop circuit includes a phase frequency detector, a bandwidth calibrator, a digital loop filter, and a digital controlled oscillator. The phase frequency detector generates a first detection value and a second detection value of which each is associated with order between a phase of a reference signal and a phase of a fed-back signal. The bandwidth calibrator amplifies a signal level of the second detection value by a gain value to generate an amplified detection value, and adjusts the gain value based on the first detection value. The digital loop filter generates a digital code based on the amplified detection value. The digital controlled oscillator generates an output signal having a frequency which corresponds to the digital code. The fed-back signal is generated based on the output signal and is fed back to the phase frequency detector.

Digital phase locked loop circuit adjusting digital gain to maintain loop bandwidth uniformly

A digital phase locked loop circuit includes a phase frequency detector, a bandwidth calibrator, a digital loop filter, and a digital controlled oscillator. The phase frequency detector generates a first detection value and a second detection value of which each is associated with order between a phase of a reference signal and a phase of a fed-back signal. The bandwidth calibrator amplifies a signal level of the second detection value by a gain value to generate an amplified detection value, and adjusts the gain value based on the first detection value. The digital loop filter generates a digital code based on the amplified detection value. The digital controlled oscillator generates an output signal having a frequency which corresponds to the digital code. The fed-back signal is generated based on the output signal and is fed back to the phase frequency detector.

DIGITAL PHASE LOCKED LOOP CIRCUIT ADJUSTING DIGITAL GAIN TO MAINTAIN LOOP BANDWIDTH UNIFORMLY

A digital phase locked loop circuit includes a phase frequency detector, a bandwidth calibrator, a digital loop filter, and a digital controlled oscillator. The phase frequency detector generates a first detection value and a second detection value of which each is associated with order between a phase of a reference signal and a phase of a fed-back signal. The bandwidth calibrator amplifies a signal level of the second detection value by a gain value to generate an amplified detection value, and adjusts the gain value based on the first detection value. The digital loop filter generates a digital code based on the amplified detection value. The digital controlled oscillator generates an output signal having a frequency which corresponds to the digital code. The fed-back signal is generated based on the output signal and is fed back to the phase frequency detector.

DIGITAL PHASE LOCKED LOOP CIRCUIT ADJUSTING DIGITAL GAIN TO MAINTAIN LOOP BANDWIDTH UNIFORMLY

A digital phase locked loop circuit includes a phase frequency detector, a bandwidth calibrator, a digital loop filter, and a digital controlled oscillator. The phase frequency detector generates a first detection value and a second detection value of which each is associated with order between a phase of a reference signal and a phase of a fed-back signal. The bandwidth calibrator amplifies a signal level of the second detection value by a gain value to generate an amplified detection value, and adjusts the gain value based on the first detection value. The digital loop filter generates a digital code based on the amplified detection value. The digital controlled oscillator generates an output signal having a frequency which corresponds to the digital code. The fed-back signal is generated based on the output signal and is fed back to the phase frequency detector.

Adjusting the magnitude of a capacitance of a digitally controlled circuit

An apparatus comprises a digitally controlled circuit having a variable capacitance and a controller configured to adjust a magnitude of the variable capacitance of the digitally controlled circuit. The digitally controlled circuit comprises a plurality of gain elements, the plurality of gain elements comprising one or more positive voltage-to-frequency gain elements and one or more negative voltage-to-frequency gain elements. The controller is configured to adjust the magnitude of the capacitance by adjusting the gain provided by respective ones of the gain elements in an alternating sequence of the positive voltage-to-frequency gain elements and the negative voltage-to-frequency gain elements.

Adjusting the magnitude of a capacitance of a digitally controlled circuit

An apparatus comprises a digitally controlled circuit having a variable capacitance and a controller configured to adjust a magnitude of the variable capacitance of the digitally controlled circuit. The digitally controlled circuit comprises a plurality of gain elements, the plurality of gain elements comprising one or more positive voltage-to-frequency gain elements and one or more negative voltage-to-frequency gain elements. The controller is configured to adjust the magnitude of the capacitance by adjusting the gain provided by respective ones of the gain elements in an alternating sequence of the positive voltage-to-frequency gain elements and the negative voltage-to-frequency gain elements.

Generating divided signals from phase-locked loop (PLL) output when reference clock is unavailable

Clock generation circuit generating multiple divided signals satisfying respective desired offsets. A phase locked loop (PLL) is used to generate a PLL output having a frequency which is a desired multiple of that of a reference clock. The circuit divides the PLL output by a corresponding divisor to generate a corresponding divided signal, wherein each divided signal is offset from a common reference by at least an associated desired time offset. The common reference is timed with respect to the reference clock when the reference clock is available and with respect to a time reference signal otherwise. This arrangement is extended to use the internal time reference signal even for the cases where the reference clock is present by blocking the reference clock while the output systems across PLLs are aligned using the internal time reference signal to ensure desired offsets across different PLLs with a small uncertainty.

Generating divided signals from phase-locked loop (PLL) output when reference clock is unavailable

Clock generation circuit generating multiple divided signals satisfying respective desired offsets. A phase locked loop (PLL) is used to generate a PLL output having a frequency which is a desired multiple of that of a reference clock. The circuit divides the PLL output by a corresponding divisor to generate a corresponding divided signal, wherein each divided signal is offset from a common reference by at least an associated desired time offset. The common reference is timed with respect to the reference clock when the reference clock is available and with respect to a time reference signal otherwise. This arrangement is extended to use the internal time reference signal even for the cases where the reference clock is present by blocking the reference clock while the output systems across PLLs are aligned using the internal time reference signal to ensure desired offsets across different PLLs with a small uncertainty.

VIDEO PROCESSING DEVICE
20180063385 · 2018-03-01 · ·

Provided is a video processing device that generates a display video signal to be supplied to a liquid crystal display having a liquid crystal that is driven by a frame inversion scheme and includes a control microcomputer and a video signal processor. The control microcomputer controls a data enable signal such that a display invalid section having a predetermined number of fields is set for an interlace video signal at a predetermined period based on a vertical synchronization signal included in the interlace video signal input from outside. The video signal processor generates the display video signal by setting the display invalid section for the interlace video signal based on the data enable signal and outputs the display video signal to the liquid crystal display.

Clock Data Recovery Circuitry Associated With Programmable Logic Device Circuitry

A programmable logic device (PLD) is augmented with programmable clock data recover (CDR) circuitry to allow the PLD to communicate via any of a large number of CDR signaling protocols. The CDR circuitry may be integrated with the PLD, or it may be wholly or partly on a separate integrated circuit. The circuitry may be capable of CDR input, CDR output, or both. The CDR capability may be provided in combination with other non-CDR signaling capability such as non-CDR low voltage differential signaling (LVDS). The circuitry may be part of a larger system.