Analog Devices Global

Analog Devices International Unlimited Company

Vamshi Krishna Chillara

Declan M Dalton

Pablo Cruz Dato

Colin Gerard Lyden

Hyman Shanan

Declan D Dalton

Apparatus and methods for rotary traveling wave oscillators (RTWOs) are disclosed. In certain embodiments, an RTWO system include an RTWO ring that carries a traveling wave, a plurality of selectable capacitors distributed around the RTWO ring and each operable in a selected state and an unselected state, and a decoder system that controls selection of the plurality of selectable capacitors based on a frequency tuning code. The frequency tuning code includes a fine tuning code and a coarse tuning code, and the decoder system is operable to maintain a constant number of capacitors that toggle state for each value of the fine tuning code.

Apparatus and methods for rotary traveling wave oscillators

Aspects of this disclosure relate to reducing settling time of a ramp signal in a phase-locked loop. An offset signal can be applied to adjust an input signal provided to an integrator of a loop filter of the phase-locked loop to cause the settling time to be reduced. Disclosed methods of reducing settling time of a ramp signal can improve settling time of a ramp signal independent of the profile of the ramp signal.

Fast settling ramp generation using phase-locked loop

Aspects of this disclosure relate to reducing settling time of a sawtooth ramp signal in a phase-locked loop. Information from a loop filter of the phase-locked loop can be stored and used within the loop filter so as to improve the settling time of the sawtooth ramp signal. In certain embodiments, the settling time of a periodic sawtooth ramp signal can be reduced to less than one microsecond. An output frequency at the end of the sawtooth chirp can be brought back to an initial value without significantly modifying phase error in disclosed embodiments.

Fast settling sawtooth ramp generation in a phase-locked loop

A chip includes a phase-locked loop (PLL) and a test controller. The PLL includes an oscillator and a phase detector. In a normal mode, a first feedback loop includes a phase detector and an oscillator that generates an output based on a frequency input signal. In a test mode, the PLL is re-configured. The output of the loop filter can be decoupled from the input of the oscillator in the test mode and instead be coupled to the input of the phase detector. The oscillator can receive a test tuning signal provided by the test controller. In this test mode configuration, the PLL can measure the frequency of the oscillator.

On-chip measurement for phase-locked loop

Aspects of this disclosure relate to a digital phase-locked loop (DPLL) arranged to adjust output phase using a phase adjustment signal. In certain embodiments, the phase adjustment signal can be received in a signal path from an output of a time-to-digital converter of the DPLL to an input to the digitally controlled oscillator of the DPLL. Some embodiments relate to adjusting the output phase of the DPLL to reduce a relative phase difference between the output phase of the DPLL and an output phase of another DPLL.

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Limerick, Ireland

Vamshi Krishna Chillara