公开(公告)号：US20190028110A1

公开(公告)日：2019-01-24

申请号：US15657255

申请日：2017-07-24

Applicant: NXP B.V.

Inventor： JOS VERLINDEN ,  Sander Derksen ,  Dobson Paul Parlindungan Simanjuntak ,  Remco Cornelis Herman Van de Beek

IPC: H03L7/097 ,  H03K5/24 ,  H03K19/00 ,  H03K5/08 ,  H03K3/0231 ,  H03K3/03

Abstract: An oscillator system includes a voltage controlled oscillator (VCO) circuit. The VCO circuit includes an output for providing an oscillation signal and input to receive a voltage that controls the frequency of the oscillation signal. The oscillator system includes a frequency to voltage circuit that receives the oscillation signal and produces a voltage that is dependent upon the frequency of the oscillation signal. The oscillator system includes a comparison circuit including an amplifier. The amplifier includes an inverting input, a non inverting input, and an output. During a first phase of the comparison circuit, the non inverting input receives a reference voltage and the inverting input is coupled to the output of the amplifier via a switch and to a capacitor wherein the capacitor samples the voltage of the output. During a second phase of the comparison circuit, the non inverting input receives the voltage produced by the frequency to voltage circuit and the switch between amplifier output and inverting input is open wherein the inverting input is coupled to the capacitor to receive the sampled voltage value. During the second phase, the output of the amplifier is provided to the input of the VCO circuit.

公开(公告)号：US20190028106A1

公开(公告)日：2019-01-24

申请号：US15657250

申请日：2017-07-24

Applicant: NXP B.V.

Inventor： ANNE-JOHAN ANNEMA ,  JOS VERLINDEN

IPC: H03L7/083

Abstract: An oscillator system for an integrated circuit includes a first oscillator circuit, a second oscillator circuit, and calibration system. During a sampling routine, the calibration system is used to determine a sampled value based on a comparison of the output of the second oscillator and an external clock signal. The sampled value is stored in a memory. During a calibration routine, the calibration system determines a comparison value based on a comparison of the output of the second oscillator circuit and the output of the first oscillator circuit. The calibration circuit compares the comparison value with the sampled value to generate a tuning value to tune the frequency of the first oscillator circuit.