A tuning array selection circuit, together with a decoder and a voltage controlled oscillator (VCO), can be employed to overcome some disadvantages of previous methods of phase locked loops. For example, a VCO can include a coarse tuning array and a fine tuning array. A coarse tuning array can be used to tune a VCO to generate a signal within a wide frequency range. A fine tuning array can be used to tune a VCO to generate a signal within a narrow frequency range. In one embodiment, the narrow frequency range is within the wide frequency range. The tuning array selection circuit can coordinate selection of appropriate fine tuning devices and narrow tuning devices to reduce transition jitter and the risk of fail locking of phase locked loops.

A tuning array selection circuit, together with a decoder and a voltage controlled oscillator (VCO), can be employed to overcome some disadvantages of previous methods of phase locked loops. For example, a VCO can include a coarse tuning array and a fine tuning array. A coarse tuning array can be used to tune a VCO to generate a signal within a wide frequency range. A fine tuning array can be used to tune a VCO to generate a signal within a narrow frequency range. In one embodiment, the narrow frequency range is within the wide frequency range. The tuning array selection circuit can coordinate selection of appropriate fine tuning devices and narrow tuning devices to reduce transition jitter and the risk of fail locking of phase locked loops.

Various implementations described herein are directed to a device with a voltage-controlled oscillator that receives an enable signal, receives a reset signal, and provides internal pulse signals including one or more coarse internal pulse signals and multiple fine internal pulse signals. The device may have a coarse sampler that receives the one or more coarse internal pulse signal and provides a coarse sampled output signal. The device may have a fine sampler that receives the multiple fine internal pulse signals and provides a fine sampled output signal.

Various implementations described herein are directed to a device with a voltage-controlled oscillator that receives an enable signal, receives a reset signal, and provides internal pulse signals including one or more coarse internal pulse signals and multiple fine internal pulse signals. The device may have a coarse sampler that receives the one or more coarse internal pulse signal and provides a coarse sampled output signal. The device may have a fine sampler that receives the multiple fine internal pulse signals and provides a fine sampled output signal.

A clock synthesizer is provided. The Clock synthesizer includes a Phase Locked Loop (PLL) configured to generate a clock signal based on a reference signal. A clock buffer is connected to the PLL. The clock buffer stores the clock signal. A Duty Cycle Controller and Phase Interpolator (DCCPI) circuit is connected to the clock buffer. The DCCPI circuit receives the clock signal from the clock buffer, adjusts a duty cycle of the clock signal to substantially equal to 50%, performs phase interpolation on the clock signal, and provides the clock signal as an output after adjusting the duty cycle substantially equal to 50% and performing the phase interpolation.

A clock synthesizer is provided. The Clock synthesizer includes a Phase Locked Loop (PLL) configured to generate a clock signal based on a reference signal. A clock buffer is connected to the PLL. The clock buffer stores the clock signal. A Duty Cycle Controller and Phase Interpolator (DCCPI) circuit is connected to the clock buffer. The DCCPI circuit receives the clock signal from the clock buffer, adjusts a duty cycle of the clock signal to substantially equal to 50%, performs phase interpolation on the clock signal, and provides the clock signal as an output after adjusting the duty cycle substantially equal to 50% and performing the phase interpolation.

A method for providing a jitter signal for modulating a switching frequency of a power switch for a power converter. The method comprising receiving a drive signal representative of the switching frequency of the power switch, detecting the switching frequency from the drive signal, determining if the switching frequency is less than a first threshold frequency, and modulating a frequency of the jitter signal in response to determining if the switching frequency is less than the first threshold frequency.

A method for providing a jitter signal for modulating a switching frequency of a power switch for a power converter. The method comprising receiving a drive signal representative of the switching frequency of the power switch, detecting the switching frequency from the drive signal, determining if the switching frequency is less than a first threshold frequency, and modulating a frequency of the jitter signal in response to determining if the switching frequency is less than the first threshold frequency.

A clock synthesizer is provided. The Clock synthesizer includes a Phase Locked Loop (PLL) configured to generate a clock signal based on a reference signal. A clock buffer is connected to the PLL. The clock buffer stores the clock signal. A Duty Cycle Controller and Phase Interpolator (DCCPI) circuit is connected to the clock buffer. The DCCPI circuit receives the clock signal from the clock buffer, adjusts a duty cycle of the clock signal to substantially equal to 50%, performs phase interpolation on the clock signal, and provides the clock signal as an output after adjusting the duty cycle substantially equal to 50% and performing the phase interpolation.

A clock synthesizer is provided. The Clock synthesizer includes a Phase Locked Loop (PLL) configured to generate a clock signal based on a reference signal. A clock buffer is connected to the PLL. The clock buffer stores the clock signal. A Duty Cycle Controller and Phase Interpolator (DCCPI) circuit is connected to the clock buffer. The DCCPI circuit receives the clock signal from the clock buffer, adjusts a duty cycle of the clock signal to substantially equal to 50%, performs phase interpolation on the clock signal, and provides the clock signal as an output after adjusting the duty cycle substantially equal to 50% and performing the phase interpolation.