Circuits and processes for locking a voltage-controlled oscillator (VCO) at a high frequency signal are described. A circuit may include a voltage-controlled oscillator configured to generate a high frequency signal based on a control signal, a dummy load parallel to the voltage-controlled oscillator and configured to receive the control signal via a switch, and a digital-to-analog converter coupled to the voltage-controlled oscillator where the control signal is generated based on an output of the digital-to-analog converter.

An electronic device may include a transceiver with mixer circuitry that up-converts or down-converts signals based on a voltage-controlled oscillator (VCO) signal. The transceiver circuitry may include first, second, third, and fourth VCOs. Each VCO may include a VCO core that receives a control voltage and an inductor coupled to the VCO core. Fixed linear capacitors may be coupled between the VCO cores. A switching network may be coupled between the VCOs. Control circuitry may place the VCO circuitry in one of four different operating modes and may switch between the operating modes to selectively control current direction in each of the inductors. The VCO circuitry may generate the VCO signal within a respective frequency range in each of the operating modes. The VCO circuitry may exhibit a relatively wide frequency range across all of the operating modes while introducing minimal phase noise to the system.

An electronic device may include a transceiver with mixer circuitry that up-converts or down-converts signals based on a voltage-controlled oscillator (VCO) signal. The transceiver circuitry may include first, second, third, and fourth VCOs. Each VCO may include a VCO core that receives a control voltage and an inductor coupled to the VCO core. Fixed linear capacitors may be coupled between the VCO cores. A switching network may be coupled between the VCOs. Control circuitry may place the VCO circuitry in one of four different operating modes and may switch between the operating modes to selectively control current direction in each of the inductors. The VCO circuitry may generate the VCO signal within a respective frequency range in each of the operating modes. The VCO circuitry may exhibit a relatively wide frequency range across all of the operating modes while introducing minimal phase noise to the system.

Devices, systems, and methods for locking a voltage controlled oscillator (VCO) at a high frequency may include use of a VCO and an integrator, which generates and outputs a control signal to the VCO, based on an inverting signal and a reference signal. The control signal locks the VCO to a high frequency signal (FH). A frequency divider is coupled to the VCO, receives FH from the VCO, divides FH by a factor “F”, and outputs a low frequency signal (FL). A switched capacitor resistor circuit (SCRC) is coupled to the frequency divider and the integrator. The SCRC receives FL from the frequency divider and generates the inverting signal. An integrating capacitor is coupled across an inverting and an output terminal of op-amp in the integrator. The output of the op-amp provides an integrator signal, which may be (optionally) filtered to produce the control signal.

Oscillator circuits, electronic devices, and methods are disclosed. In one embodiment, an oscillator circuit includes a plurality of oscillator transistors comprising a plurality of gates, a plurality of adjustment transistors coupled to the plurality of gates, a differential output coupled to the plurality of oscillator transistors, a plurality of current transistors configured to receive one or more mixed bias current outputs, and generate a main current based on the one or more mixed bias current outputs, the one or more mixed bias current outputs and the main current being substantially constant over a range of temperatures, and one or more switches configured to set an oscillation frequency of the differential output by driving a first portion of a main current through at least one of the plurality of oscillator transistors, and driving a second portion of the main current through at least one of the plurality of adjustment transistors.

An oscillating circuit comprises a constant voltage supply circuit, a constant current supply circuit and an oscillating circuit; the constant voltage supply circuit is configured to output constant voltage; the constant current supply circuit is configured to output constant current; and the oscillating circuit is connected to the constant voltage supply circuit and the constant current supply circuit, and is configured to generate an oscillating signal with a preset frequency according to the constant voltage and the constant current.

Circuits and processes for locking a voltage-controlled oscillator (VCO) at a high frequency signal are described. A circuit may include an adjustable current converter (ACC), coupled at an input terminal to a power source, operable to output a control signal (VC) at an output terminal. A first switch may be coupled to the ACC and to the VCO. The VCO, when in an “ON” state, receives the control signal and outputs a high frequency signal (VHF). A digital filter may be coupled to the VCO and operable to receive the VHF. Based on the VHF, the digital filter generates a data signal having a data value. The circuit may also include a digital-to-analog converter (DAC) operable to receive the data signal and, based on the data value, output an adjustment signal to the ACC. The ACC may adjust the control signal based on the adjustment signal received from the DAC.

Devices, systems, and methods for locking a voltage controlled oscillator (VCO) at a high frequency may include use of a VCO and an integrator, which generates and outputs a control signal to the VCO, based on an inverting signal and a reference signal. The control signal locks the VCO to a high frequency signal (FH). A frequency divider is coupled to the VCO, receives FH from the VCO, divides FH by a factor “F”, and outputs a low frequency signal (FL). A switched capacitor resistor circuit (SCRC) is coupled to the frequency divider and the integrator. The SCRC receives FL from the frequency divider and generates the inverting signal. An integrating capacitor is coupled across an inverting and an output terminal of op-amp in the integrator. The output of the op-amp provides an integrator signal, which may be (optionally) filtered to produce the control signal.

An apparatus is disclosed for implementing multi-mode oscillation circuitry with stepping control. In an example aspect, the multi-mode oscillation circuitry comprises a resonator coupled to a first oscillator and a second oscillator. The multi-mode oscillation circuitry is configured to selectively be in a first configuration with the first oscillator in an active state and the second oscillator in an inactive state or a second configuration with the first oscillator in the inactive state and the second oscillator in the active state. The apparatus also includes a step-control circuit coupled to the multi-mode oscillation circuitry. The step-control circuit is configured to cause the first oscillator to switch from the inactive state to the active state and incrementally increase a first gain of the first oscillator based on the first oscillator being in the active state to enable the multi-mode oscillation circuitry to transition from the second configuration to the first configuration.

Apparatuses and methods for transmitting a command mode (e.g., operation mode) associated with a command between devices are disclosed. One device may be configured as a master and one or more devices may be configured as slaves. The command mode may be transmitted by the master to the slaves by setting a resting state of a clock signal transmitted between the devices and transitioning a device enable signal to an active state. The slaves may detect the resting state of the clock at the time the enable signal is transitioned to the active state in order to determine the command mode of the command. The devices may then execute the command in the mode indicated by the transmitted command mode.