Circuit device, oscillator, electronic apparatus, and vehicle

Patent metadata

Field	Value
Publication number	US-2017194967-A1
Application number	US-201615385325-A
Country	US
Kind code	A1
Filing date	Dec 20, 2016
Priority date	Jan 6, 2016
Publication date	Jul 6, 2017
Grant date	—

Abstract

A circuit device includes an oscillation signal generation circuit that generates an oscillation signal having an oscillation frequency set by the frequency control data by using a resonator, and a processor that is configured to perform a signal process on input frequency control data to output frequency control data. The processor is configured to obtain a pre-estimated value x̂ − (k) at a time step k by adding a post-estimated value x̂(k−1) and a correction value D(k−1) at a time step k−1 together during a process of updating a pre-estimated value in a Karman filter process, and perform aging correction on the frequency control data on the basis of a result of the Karman filter process.

First claim

What is claimed is:

1 . A circuit device comprising:
an oscillation signal generation circuit that generates an oscillation signal having an oscillation frequency set by frequency control data by using a resonator a processor that is configured to;
perform a signal process on input frequency control data to output the frequency control data;
obtain a pre-estimated value x̂ − (k) at a time step k by adding a post-estimated value x̂(k−1) and a correction value D(k−1) at a time step k−1 together during a process of updating a pre-estimated value in a Karman filter process; and
perform aging correction on the frequency control data on the basis of a result of the Karman filter process.

2 . The circuit device according to claim 1 ,
wherein the processor is configured to obtain the correction value D(k−1) on the basis of an observation residual in the Karman filter process.

3 . The circuit device according to claim 1 ,
wherein the processor is configured to obtain the pre-estimated value x̂ − (k) at the time step k according to x̂ − (k)=x̂(k−1)+D(k−1) by adding the post-estimated value x̂(k−1) and the correction value D(k−1) at the time step k−1 together.

4 . The circuit device according to claim 3 ,
wherein the processor is configured to obtain the correction value D(k) at the time step k on the basis of the correction value D(k−1) at the time step k−1 and an observation residual ek in the Karman filter process.

5 . The circuit device according to claim 4 ,
wherein, in a case where a constant is indicated by E, the processor is configured to obtain the correction value D(k) according to D(k)=D(k−1)+E·ek.

6 . The circuit device according to claim 5 , further comprising:
a storage that stores the constant E.

7 . The circuit device according to claim 1 ,
wherein the processor is configured to
perform the signal process on the input frequency control data which is based on a phase comparison result between an input signal based on the oscillation signal and a reference signal,
estimate a true value for an observed value of the input frequency control data through the Karman filter process in a period before a hold-over state due to the absence or abnormality of the reference signal is detected, and
generate aging-corrected frequency control data, in a case where the hold-over state is detected, by holding the true value at a timing corresponding to a timing of detecting the hold-over state, and by performing a calculation based on the true value.

8 . The circuit device according to claim 7 ,
wherein the processor is configured to generate the aging-corrected frequency control data by performing the calculation of adding the correction value to the true value.

9 . The circuit device according to claim 8 ,
wherein the processor is configured to perform the calculation of adding the correction value after a filter process to the true value.

10 . The circuit device according to claim 1 , further comprising:
a storage that stores a system noise constant for setting system noise in the Karman filter process and an observation noise constant for setting observation noise in the Karman filter process.

11 . The circuit device according to claim 1 , further comprising:
a digital interface that monitors the pre-estimated value and an observed value.

12 . An oscillator comprising:
the circuit device according to claim 1 ; and the resonator.

13 . An electronic apparatus comprising the circuit device according to claim 1 .

14 . A vehicle comprising the circuit device according to claim 1 .

Assignees

• Seiko Epson Corp

Inventors

• Yonezawa Takemi

Classifications

• H03L1/00

  Stabilisation of generator output against variations of physical values, e.g. power supply · CPC title

• H03L2207/50

  All digital phase-locked loop · CPC title

• H03B5/362

  the amplifier being a single transistor (H03B5/364 - H03B5/368 take precedence) · CPC title

• H03L1/026 Primary

  by using a memory for digitally storing correction values (H03L1/025 takes precedence) · CPC title

• H03B5/368

  the means being voltage variable capacitance diodes · CPC title