A current control device for a differential circuit is provided. The current control device includes a differential circuit that generates differential signals comprising a positive signal and a negative signal in opposite phases, an amplitude detection circuit detecting an amplitude of the differential signal and outputting first and second detection voltages, an error amplification circuit controlling the differential circuit on the basis of an error voltage between the first and second detection voltages, and a current control circuit controlling the amplitude detection circuit on the basis of any one of the first and second detection voltages.

An amplitude limiting oscillation circuit is disclosed. The amplitude limiting oscillation circuit includes: an oscillation circuit, configured to generate an oscillation signal; a pulse width modulation circuit, configured to generate a pulse width modulation signal according to an amplitude of the oscillation signal; a low pass filtering circuit, configured to convert the pulse width modulation signal into a direct current control voltage signal, where the direct current control voltage signal is configured to control a voltage controlled resistance circuit; and the voltage controlled resistance circuit, configured to change a resistance value of the voltage controlled resistance circuit according to under the direct current control voltage signal, to control the amplitude of the oscillation signal. The amplitude limiting oscillation circuit, may improve performance of the amplitude limiting oscillation circuit.

Methods and apparatus generate an oscillating output signal having a voltage swing greater than a voltage swing across nodes of active devices. An example oscillator includes a tank to generate an oscillating output signal in response receiving an edge of an enable signal; a feedback generator including a first gain stage forming a first feedback loop with the tank, the first feedback loop providing a first charge to maintain the oscillating output signal and a second gain stage forming a second feedback loop with the tank, the second feedback loop providing a second charge to maintain the oscillating output signal, the first and second charges combining with the oscillating output signal to generate a high voltage swing; and an attenuator connected between the tank and the feedback generator to isolate the tank from active components of the feedback generator.

In one embodiment, an apparatus includes a voltage controlled oscillator (VCO) to output an oscillating signal. The VCO may have a tank formed of at least one capacitor coupled in parallel with at least one inductor, and a plurality of transconductors to provide energy to the tank. At least one of the plurality of transconductors can be controllably switched to be coupled to the tank or to be decoupled from the tank.

A wireless communication apparatus includes an oscillator circuit configured to generate an oscillation signal corresponding to an oscillation frequency determined by an antenna, and a bias generator circuit configured to reconfigure an operation region mode of a transistor included in the oscillator circuit by adjusting a bias signal in response to an enable signal.

Methods and apparatus are disclosed to generate an oscillating output signal having a voltage swing greater than a voltage swing across nodes of active devices. An example oscillator includes a tank to generate an oscillating output signal in response receiving an edge of an enable signal; a feedback generator including a first gain stage forming a first feedback loop with the tank, the first feedback loop providing a first charge to maintain the oscillating output signal and a second gain stage forming a second feedback loop with the tank, the second feedback loop providing a second charge to maintain the oscillating output signal, the first and second charges combining with the oscillating output signal to generate a high voltage swing; and an attenuator connected between the tank and the feedback generator to isolate the tank from active components of the feedback generator.

A radio frequency (RF) transceiver includes a first oscillator configured to generate a first oscillation frequency associated with an RF signal, a second oscillator configured to generate a second oscillation frequency associated with a clock frequency, a counter configured to generate a counter output signal using the first oscillation frequency and the second oscillation frequency, and a comparer configured to generate a digital output signal associated with the RF signal by comparing an output value of the counter output signal to a reference value.

A planar differential inductor reduces an effect of parasitics on common mode inductance of a voltage controlled oscillator (VCO)-based inductor to properly ground a common mode alternating current (AC) ground. In one instance, the planar differential inductor includes a ground plane, routing lines, distributed capacitors, an exterior inductor structure, and an interior inductor structure. The planar differential inductor may be coupled to a capacitor as part of an LC tank that operates as a resonator within a VCO. The bypass capacitor array is coupled between the ground plane and the routing lines. The exterior inductor structure is coupled between the routing lines and a power supply. The interior inductor is within the ground plane and coupled between the routing lines and differential ports.

Certain aspects of the disclosure are directed to electrostatic discharge protection of an integrated circuit clock. According to a specific example, circuitry includes a direct-current power supply, a voltage-controlled oscillation (VCO) circuit, an electrostatic protection circuit, and a voltage regulator. The VCO circuit has an oscillation frequency and includes an amplification circuit and capacitance circuitry. The electrostatic protection circuit is arranged to connect power to the VCO circuit while reducing variation in the oscillation frequency of the VCO circuit resulting from electrostatic energy. The voltage regulator is connected between the direct-current power supply and a power supply connection at which the direct-current power is connected to the VCO, and is configured to mitigate an imbalance of electric charges from adversely altering a tuning capacitance of the VCO established by the capacitance circuitry.

A voltage-controlled oscillator, including a voltage-controlled LC resonator including at least one first output node; an amplifier including at least one first dual-gate MOS transistor including first and second gates, coupling the first output node to a second node of application of a reference potential; and a regulation circuit capable of applying to the second gate of the first transistor a bias voltage variable according to the amplitude of the oscillations of a signal delivered on the first output node of the oscillator.