Semiconductor device and oscillation circuit

Patent metadata

Field	Value
Publication number	US-11728770-B2
Application number	US-202017620494-A
Country	US
Kind code	B2
Filing date	Jun 15, 2020
Priority date	Jun 17, 2019
Publication date	Aug 15, 2023
Grant date	Aug 15, 2023

Abstract

A semiconductor device including a first inverter circuit connected in parallel to a crystal vibrating element; a second inverter circuit connected to the first inverter circuit so as to share an input therewith, and outputting an oscillation signal; and a wave filter connected to the second inverter circuit and having a passband that is determined in advance and includes an oscillation frequency of the oscillation signal.

First claim

The invention claimed is:

1. A semiconductor device, comprising:
a first inverter circuit connected in parallel to a crystal vibrating element;
a second inverter circuit connected to the first inverter circuit so as to share an input therewith, and output an oscillation signal; and
a wave filter connected to the second inverter circuit and having a passband that is determined in advance and includes an oscillation frequency of the oscillation signal,
wherein the wave filter is configured by a plurality of wave filters that are connected in series, and
the wave filter is a bandpass filter having a third inverter circuit, a capacitor connected in series to an input of the third inverter circuit, and a resistor connected between the input and an output of the third inverter circuit.

2. The semiconductor device of claim 1 , wherein a gate width ratio, which is a ratio of a gate width of a P-type field effect transistor to a gate width of an N-type field effect transistor, at the first inverter circuit and a gate width ratio of the second inverter circuit are substantially the same.

3. The semiconductor device of claim 1 , wherein at least one of a capacitance value of the capacitor or a resistance value of the resistor is variable.

4. The semiconductor device of claim 1 , wherein the second inverter circuit is disposed between a plurality of the first inverter circuits, as seen in a plan view.

5. An oscillation circuit, comprising:
the semiconductor device of claim 1 ; and
the crystal vibrating element connected in parallel to the first inverter circuit.

Assignees

• Lapis Semiconductor Co Ltd

Inventors

• Nakanishi Koki

Classifications

• H03B5/32 Primary

  being a piezoelectric resonator (selection of piezoelectric material H10N30/00) · CPC title

• H03H11/04

  Frequency selective two-port networks · CPC title

• H03H11/1213

  using transistor amplifiers (H03H11/1204 takes precedence; parallel-T filters H03H11/1295) · CPC title

• H03K3/3545

  Stabilisation of output, e.g. using crystal · CPC title

• H03L1/02

  against variations of temperature only · CPC title