Semiconductor device, movement and electronic watch

Patent metadata

Field	Value
Publication number	US-10826430-B2
Application number	US-201916554670-A
Country	US
Kind code	B2
Filing date	Aug 29, 2019
Priority date	Aug 30, 2018
Publication date	Nov 3, 2020
Grant date	Nov 3, 2020

Abstract

An oscillating circuit includes an input terminal and an output terminal, to both of which an oscillator is coupled, a DC cut capacitor having one terminal of two terminals that is coupled to the input terminal, an inverter having an input side coupled to the other terminal of the DC cut capacitor and an output side coupled to the output terminal, a first feedback resistor coupled in parallel to the inverter, a second feedback resistor coupled in parallel to the DC cut capacitor and the inverter, and a switch coupled in parallel to the DC cut capacitor.

First claim

What is claimed is:

1. A semiconductor device comprising an oscillating circuit and a control circuit, wherein the oscillating circuit includes
an input terminal and an output terminal, to both of which an oscillator is coupled,
a DC cut capacitor having one terminal coupled to the input terminal,
an inverter coupled between the other terminal of the DC cut capacitor and the output terminal,
a first feedback resistor coupled in parallel to the inverter,
a second feedback resistor coupled in parallel to the DC cut capacitor and the inverter, and
a switch coupled in parallel to the DC cut capacitor, and
at a start of oscillation of the oscillator, the control circuit is configured to short-circuit the switch, the second feedback resistor forms a signal path bypassing the DC cut capacitor and is coupled in parallel to the first feedback resistor, and a feedback resistance of the inverter is configured by the first feedback resistor and the second feedback resistor which are coupled in parallel, and
after a predetermined time has elapsed from the start of the oscillation, the control circuit is configured to open the switch, and the second feedback resistor functions as a circuit that stabilizes a potential of the input terminal.

2. A semiconductor device comprising an oscillating circuit and a control circuit, wherein
the oscillating circuit includes
an input terminal and an output terminal, to both of which an oscillator is coupled,
a DC cut capacitor having one terminal coupled to the input terminal,
an inverter coupled between the other terminal of the DC cut capacitor and the output terminal,
a first feedback resistor coupled in parallel to the inverter,
a second feedback resistor coupled in parallel to the DC cut capacitor and the inverter,
a first switch coupled in parallel to the DC cut capacitor,
a second switch coupled between an input side of the first feedback resistor and an input side of the inverter,
a third switch coupled between an output side of the inverter and a point between the second switch and the first feedback resistor, and
a fourth switch coupled between the output side of the inverter and output sides of the first feedback resistor and the second feedback resistor, and
the control circuit is configured to short-circuit the first switch and the third switch and open the second switch and the fourth switch at a start of oscillation of the oscillator, and open the first switch and the third switch and short-circuit the second switch and the fourth switch after a predetermined time elapsed from the start of the oscillation.

3. A semiconductor device comprising an oscillating circuit and a control circuit, wherein
the oscillating circuit includes
an input terminal and an output terminal, to both of which an oscillator is coupled,
a DC cut capacitor having one terminal coupled to the input terminal,
an inverter coupled between the other terminal of the DC cut capacitor and the output terminal,
a first feedback resistor coupled in parallel to the inverter,
a second feedback resistor coupled in parallel to the DC cut capacitor and the inverter,
a first switch coupled in parallel to the DC cut capacitor,
a second switch coupled between an input side of the second feedback resistor and an input side of the DC cut capacitor,
a third switch coupled between an output side of the inverter and a point between the second switch and the second feedback resistor, and
a fourth switch coupled between the output side of the inverter and output sides of the first feedback resistor and the second feedback resistor, and
the control circuit is configured to short-circuit the first switch and the third switch and open the second switch and the fourth switch at a start of oscillation of the oscillator, and open the first switch and the third switch and short-circuit the second switch and the fourth switch after a predetermined time elapsed from the start of the oscillation.

4. A watch movement comprising the semiconductor device according to claim 1 .

5. An electronic watch comprising the semiconductor device according to claim 1 .

6. A watch movement comprising the semiconductor device according to claim 2 .

7. An electronic watch comprising the semiconductor device according to claim 2 .

8. A watch movement comprising the semiconductor device according to claim 3 .

9. An electronic watch comprising the semiconductor device according to claim 3 .

Assignees

• Seiko Epson Corp

Inventors

• Ninomiya Masaya

Classifications

• G04G19/00

  Electric power supply circuits specially adapted for use in electronic time-pieces · CPC title

• G04C3/143 Primary

  Means to reduce power consumption by reducing pulse width or amplitude and related problems, e.g. detection of unwanted or missing step · CPC title

• H03B2200/0094

  Measures to ensure starting of oscillations · CPC title

• G04G3/02

  Circuits for deriving low frequency timing pulses from pulses of higher frequency (pulse frequency dividers in general H03K23/00 - H03K29/00) · CPC title

• H03B5/364 Primary

  the amplifier comprising field effect transistors (H03B5/366 takes precedence) · CPC title