In an example, a system includes an oscillator circuit on a chip. The oscillator circuit includes a charging current generator including a current mirror and an amplifier, where the amplifier is coupled to a pin of the chip. The oscillator circuit also includes a first switch coupled to the pin, a second switch coupled to the pin and to a charging resistor, and a third switch coupled to the amplifier and an internal resistor, where the internal resistor is internal to the chip. The oscillator circuit includes a bias current source coupled to the current mirror. The system includes an external resistor coupled to the pin, where the external resistor is external to the chip. The system also includes an external capacitor coupled to the pin and coupled in parallel to the external resistor, where the external capacitor is external to the chip.

A method using a phase locked loop (PLL) includes receiving a reference frequency. The method further includes generating a control signal based on the reference frequency. The method further includes adjusting an output signal based on the control signal. Adjusting the output signal includes operating a plurality of switches in response to the control signal, wherein operating the plurality of switches comprises selectively electrically connecting a first ground plane to a first floating plane, wherein the first floating plane is between the first ground plane and the signal line, and the first floating plane is a same distance from a substrate as the first ground plane.

An integrated circuit includes an oscillator and a power amplifier. The oscillator includes a first node, a second node, and a network of one or more reactive components coupled between the first node and the second node. The power amplifier includes a first input coupled to the first output of the oscillator, a second input coupled to the second output of the oscillator, and an output. The power amplifier includes a coarse gain control circuit, a first amplifier stage, and a second amplifier stage.

A first phase adjuster adjusts the phase of any one of first and second AC voltages generated in a negative resistance circuit so that a shift amount Φ in a first variable phase shifter falls within a range of 0 degrees≤Φ<180 degrees, and outputs the phase-adjusted AC voltage to the first variable phase shifter, and a second phase adjuster adjusts the phase of the other one of the first and second AC voltages generated in the negative resistance circuit so that a shift amount Φ in a second variable phase shifter falls within a range of 0 degrees≤Φ<180 degrees, and outputs the phase-adjusted AC voltage to the second variable phase shifter.

A method is provided for enhancing the detection of the start time of a reference oscillator (4) of a super-regenerative receiver (1), which includes the reference oscillator, a bias current generator (7), an oscillation detector (6), and an impedance matching unit (3). Following the supply of the bias current (i_vco) after receiving the activation control signal (Sosc), an oscillation detection is performed by the oscillation detector (6), and once oscillation is detected, an additional amplification current (iboost) dependent on the envelope of the detected oscillation, of an amplification current generation circuit is supplied to the reference oscillator (4) in addition to the bias current to amplify the oscillation signal to be above a critical oscillation start threshold so as to precisely define the start time of the oscillator, and enable the oscillation detector (6) to order the stoppage of oscillation of the reference oscillator (4).

Apparatus and methods for generating multiple oscillating signals. An example circuit generally includes a first voltage-controlled oscillator (VCO) circuit and a second VCO circuit having a differential bias input coupled to a differential output of the first VCO circuit. At least one of the first VCO circuit or the second VCO circuit generally includes: a pair of cross-coupled transistors comprising a first transistor and a second transistor, a first inductive element coupled between a first node and the drain of the first transistor, a second inductive element coupled between the first node and the drain of the second transistor, a third transistor having a drain coupled to the drain of the first transistor and having a source coupled to a second node, and a fourth transistor having a drain coupled to the drain of the second transistor and having a source coupled to the second node.

An apparatus for communicating across an isolation barrier includes a differential pair of input terminals. The apparatus includes a bandpass filter circuit configured to receive a received signal on the differential pair of input terminals and to provide a received differential signal on a differential pair of nodes. The apparatus includes a demodulator directly coupled to the bandpass filter circuit and configured to directly demodulate the received differential signal on the differential pair of nodes to provide a demodulated received signal.

Described is a high Q-factor inductor. The inductor is formed as a unit cell coil, which is copied twice for a dual-coil inductor and copied four times for a quad-coil inductor. For each copy of the unit cell coil, the coil is rotated a subsequent substantially 90 degrees or substantially −90 degrees. The rotation enables the terminals of the inductor to be routed equal-distant to a circuit that is placed in the line of symmetry between the two coils.

A method is provided for enhancing the detection of the start time of a reference oscillator (4) of a super-regenerative receiver (1), which includes the reference oscillator, a bias current generator (7), an oscillation detector (6), and an impedance matching unit (3). Following the supply of the bias current (i_vco) after receiving the activation control signal (Sosc), an oscillation detection is performed by the oscillation detector (6), and once oscillation is detected, an additional amplification current (iboost) dependent on the envelope of the detected oscillation, of an amplification current generation circuit is supplied to the reference oscillator (4) in addition to the bias current to amplify the oscillation signal to be above a critical oscillation start threshold so as to precisely define the start time of the oscillator, and enable the oscillation detector (6) to order the stoppage of oscillation of the reference oscillator (4).

The present invention provides an oscillator including a tapped inductor and a cross-coupled pair. The tapped inductor includes a first terminal, a second terminal, a first tap and a second tap. The cross-coupled pair receives two input signals from the first terminal and the second terminal to generate two output signals to the first tap and the second tap, respectively.