Abstract: A phase interpolator includes an adaptively biased phase mixer, phase control circuitry and an adaptive bias generator. The adaptively biased phase mixer has mixing transistor circuitry configured to provide an output phase signal in response to a plurality of phase control signals, a bias current, and a number of phase input signals offset in phase from one another. The adaptively biased phase mixer further has adjustable bias transistor circuitry configured to adjust the bias current provided to the mixing transistor circuitry in response to an adaptive bias signal.

Abstract: A phase interpolator includes an adaptively biased phase mixer, phase control circuitry and an adaptive bias generator. The adaptively biased phase mixer has mixing transistor circuitry configured to provide an output phase signal in response to a plurality of phase control signals, a bias current, and a number of phase input signals offset in phase from one another. The adaptively biased phase mixer further has adjustable bias transistor circuitry configured to adjust the bias current provided to the mixing transistor circuitry in response to an adaptive bias signal.

Abstract: A gain control circuit, suitable for controlling the amplitude of a voltage-controlled oscillator, includes a duty cycle detector, an analog-to-digital converter, and a function generator. The gain control circuit provides a digitally enabled negative feedback loop. The duty cycle detector generates an estimate of the amplitude. The function generator receives a target amplitude as well as a digital representation of the estimate of the amplitude. The function generator calculates a modified estimate and periodically compares the same to the target value to generate a control word. The control word is arranged to enable current sources in the voltage-controlled oscillator.

Abstract: A gain control circuit, suitable for controlling the amplitude of a voltage-controlled oscillator, includes a duty cycle detector, an analog-to-digital converter, and a function generator. The gain control circuit provides a digitally enabled negative feedback loop. The duty cycle detector generates an estimate of the amplitude. The function generator receives a target amplitude as well as a digital representation of the estimate of the amplitude. The function generator calculates a modified estimate and periodically compares the same to the target value to generate a control word. The control word is arranged to enable current sources in the voltage-controlled oscillator.