A circuit includes a voltage-controlled oscillator (VCO) and a frequency divider. The frequency divider input is coupled to the VCO output. The circuit further includes a phase-frequency detector (PFD). A control output of the PFD is coupled to the VCO. A first PFD input is coupled to a first frequency divider output, and a second PFD input is coupled to a second frequency divider output. The first frequency divider output is configured to provide a first frequency divider signal and the second frequency divider output is configured to provide a second frequency divider signal 90 degrees out of phase with respect to the first frequency divider signal. The PFD is configured to detect an occurrence of at least two edges of a signal on the data input while the second frequency divider signal is continuously logic high across the at least two edges.

A circuit includes a voltage-controlled oscillator (VCO) and a frequency divider. The frequency divider input is coupled to the VCO output. The circuit further includes a phase-frequency detector (PFD). A control output of the PFD is coupled to the VCO. A first PFD input is coupled to a first frequency divider output, and a second PFD input is coupled to a second frequency divider output. The first frequency divider output is configured to provide a first frequency divider signal and the second frequency divider output is configured to provide a second frequency divider signal 90 degrees out of phase with respect to the first frequency divider signal. The PFD is configured to detect an occurrence of at least two edges of a signal on the data input while the second frequency divider signal is continuously logic high across the at least two edges.

A two-chip die module with minimal chip-to-chip clock skew is provided. The two-chip die module includes a common substrate, first and second chips operably disposed on the common substrate to be communicative in parallel with one another and a single phase lock loop (PLL). The PLL is disposed within one of the first and second chips to provide a source for a common clock signal for the first and second chips. PLL signals of the PLL to the first and second chips are nearly equal and clock sample signals of the first and second chips are nearly equal.

A two-chip die module with minimal chip-to-chip clock skew is provided. The two-chip die module includes a common substrate, first and second chips operably disposed on the common substrate to be communicative in parallel with one another and a single phase lock loop (PLL). The PLL is disposed within one of the first and second chips to provide a source for a common clock signal for the first and second chips. PLL signals of the PLL to the first and second chips are nearly equal and clock sample signals of the first and second chips are nearly equal.

An apparatus includes a digitally controlled oscillator (DCO), which includes an inductor coupled in series with a first capacitor. The DCO further includes a second capacitor coupled in parallel with the series-coupled inductor and first capacitor, a first inverter coupled in parallel with the second capacitor, and a second inverter coupled back-to-back to the first inverter. The DCO further includes a digital-to-analog-converter (DAC) to vary a capacitance of the first capacitor.

An apparatus includes a digitally controlled oscillator (DCO), which includes an inductor coupled in series with a first capacitor. The DCO further includes a second capacitor coupled in parallel with the series-coupled inductor and first capacitor, a first inverter coupled in parallel with the second capacitor, and a second inverter coupled back-to-back to the first inverter. The DCO further includes a digital-to-analog-converter (DAC) to vary a capacitance of the first capacitor.

An integrated circuit (IC) includes input/output (I/O) ports, each operating using one of a pair of unequal power supplies during normal operation of the IC. A lower supply of the pair of unequal power supplies is required to be used as the power supply for the I/O port when a first input signal to the IC is received from an external source on a first I/O port of the I/O ports. The voltage range of the logic excursions of the first input signal is greater than the range from a magnitude of the lower supply to a constant reference potential. A regulation loop derives a derived lower supply having a magnitude equaling that of the lower supply from the higher supply of the pair of unequal power supplies, and applies the derived lower supply on a power supply node of the first I/O port.

An integrated circuit (IC) includes input/output (I/O) ports, each operating using one of a pair of unequal power supplies during normal operation of the IC. A lower supply of the pair of unequal power supplies is required to be used as the power supply for the I/O port when a first input signal to the IC is received from an external source on a first I/O port of the I/O ports. The voltage range of the logic excursions of the first input signal is greater than the range from a magnitude of the lower supply to a constant reference potential. A regulation loop derives a derived lower supply having a magnitude equaling that of the lower supply from the higher supply of the pair of unequal power supplies, and applies the derived lower supply on a power supply node of the first I/O port.

A phase locked loop has an oscillator that varies a frequency according to a control signal, a resonance element that resonates at a predetermined resonance frequency and output a signal obtained by shifting a phase of an output signal of the oscillator by 90 degrees at the resonance frequency, a phase detector that detects a phase error between an output signal of the resonance element and an output signal of the oscillator, a feedback controller that controls a frequency of an output signal of the oscillator by proportional control and integral control according to the phase error, and a control signal corrector that corrects the control signal by adding a correction term corresponding to environment information to an output signal of the feedback controller.

A phase locked loop has an oscillator that varies a frequency according to a control signal, a resonance element that resonates at a predetermined resonance frequency and output a signal obtained by shifting a phase of an output signal of the oscillator by 90 degrees at the resonance frequency, a phase detector that detects a phase error between an output signal of the resonance element and an output signal of the oscillator, a feedback controller that controls a frequency of an output signal of the oscillator by proportional control and integral control according to the phase error, and a control signal corrector that corrects the control signal by adding a correction term corresponding to environment information to an output signal of the feedback controller.