Provided is a circuit device including: a first terminal electrically coupled to one end of a vibrator; a second terminal electrically coupled to the other end of the vibrator; an oscillation circuit electrically coupled to the first terminal and the second terminal, and oscillating the vibrator; a third terminal to which an external input signal is input; a switch circuit provided between a first wiring which couples the first terminal and the oscillation circuit with each other and the third terminal, and having a P-type transistor; and a control circuit outputting a regulated voltage, in which a power supply voltage is regulated, as a substrate voltage of the P-type transistor.

A periodic output generator has a first clock source coupled to a first counter and a second clock source with a frequency greater than the first clock source, the second clock source coupled to a second counter, the first clock source operating continuously, the second clock source enabled when the first clock source reaches a count C1. The second clock source generates an output when a count C2 is reached, and the counters are reset and the process repeats. In another example, a timestamp generator has a high speed clock and a real time clock operative on a low speed clock. The timestamp generator receives an external event, turns on the high speed clock generator and counts high speed clock cycles C until the arrival of the next time stamp, and computes an event timestamp as the next timestamp less c/f, less the startup time of the high speed clock.

A dual-mode oscillator and a multi-phase oscillator includes a mode switching circuit to switch between two operating modes and obtain oscillation signals having two different bands. The dual-mode oscillator also includes two transformer-coupled oscillators with each having a step-up transformer. The step-up transformer multiplies a drain voltage swing of a first metal oxide semiconductor (MOS) transistor and then injects a voltage signal to a gate of a second MOS transistor to obtain a larger gate voltage swing without increasing a supply voltage of the oscillator. The dual-mode oscillators are coupled through multi-phase coupled circuits to form a Mobius loop.

A dual-mode oscillator and a multi-phase oscillator includes a mode switching circuit to switch between two operating modes and obtain oscillation signals having two different bands. The dual-mode oscillator also includes two transformer-coupled oscillators with each having a step-up transformer. The step-up transformer multiplies a drain voltage swing of a first metal oxide semiconductor (MOS) transistor and then injects a voltage signal to a gate of a second MOS transistor to obtain a larger gate voltage swing without increasing a supply voltage of the oscillator. The dual-mode oscillators are coupled through multi-phase coupled circuits to form a Mobius loop.

Relax oscillation circuits have at least one comparison circuit that is structured with a flipped gate transistor and a normal MOS transistor wherein the two transistors having different threshold voltages. The relaxation oscillators are configured for charging and discharging capacitances between the threshold voltages of the flipped gate transistor and the normal MOS transistor by toggling the state of a latching circuit to control the charging and discharging of the capacitances.

Relax oscillation circuits have at least one comparison circuit that is structured with a flipped gate transistor and a normal MOS transistor wherein the two transistors having different threshold voltages. The relaxation oscillators are configured for charging and discharging capacitances between the threshold voltages of the flipped gate transistor and the normal MOS transistor by toggling the state of a latching circuit to control the charging and discharging of the capacitances.

A periodic output generator has a first clock source coupled to a first counter and a second clock source with a frequency greater than the first clock source, the second clock source coupled to a second counter, the first clock source operating continuously, the second clock source enabled when the first clock source reaches a count C1. The second clock source generates an output when a count C2 is reached, and the counters are reset and the process repeats. In another example, a timestamp generator has a high speed clock and a real time clock operative on a low speed clock. The timestamp generator receives an external event, turns on the high speed clock generator and counts high speed clock cycles C until the arrival of the next time stamp, and computes an event timestamp as the next timestamp less c/f, less the startup time of the high speed clock.

Systems and methods are provided for compensating for mechanical acceleration at a reference oscillator. A reference oscillator provides an oscillator output signal and an accelerometer on a same platform as the reference oscillator, such that mechanical acceleration at the reference oscillator is detected at the accelerometer to produce a measured acceleration. A filter assembly, having an associated set of filter weights, receives the measured acceleration from the accelerometer and provides a tuning control signal responsive to the measured acceleration to a frequency reference associated with the system. An adaptive weighting component receives the oscillator output signal of the reference oscillator and an external signal that is provided from a source external to the platform and adjusts the set of filter weights for the filter assembly based on a comparison of the external signal and the oscillator output signal.

Systems and methods are provided for compensating for mechanical acceleration at a reference oscillator. A reference oscillator provides an oscillator output signal and an accelerometer on a same platform as the reference oscillator, such that mechanical acceleration at the reference oscillator is detected at the accelerometer to produce a measured acceleration. A filter assembly, having an associated set of filter weights, receives the measured acceleration from the accelerometer and provides a tuning control signal responsive to the measured acceleration to a frequency reference associated with the system. An adaptive weighting component receives the oscillator output signal of the reference oscillator and an external signal that is provided from a source external to the platform and adjusts the set of filter weights for the filter assembly based on a comparison of the external signal and the oscillator output signal.

Some embodiments include apparatuses and methods of using the apparatuses. One of the apparatuses includes an inductor included in an integrated circuit device, and a first oscillator and a second oscillator included in the integrated circuit device. The first oscillator includes a first terminal coupled to a conductive path of the inductor to provide a first signal. The second oscillator includes a second terminal coupled to the conductive path to provide a second signal. The first and second signals have different frequencies.