CN106503338B - Anti-electromagnetic interference crystal oscillator resonant circuit - Google Patents
Anti-electromagnetic interference crystal oscillator resonant circuit Download PDFInfo
- Publication number
- CN106503338B CN106503338B CN201610924231.0A CN201610924231A CN106503338B CN 106503338 B CN106503338 B CN 106503338B CN 201610924231 A CN201610924231 A CN 201610924231A CN 106503338 B CN106503338 B CN 106503338B
- Authority
- CN
- China
- Prior art keywords
- side wall
- crystal oscillator
- electromagnetic interference
- crystal
- layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/30—Circuit design
- G06F30/39—Circuit design at the physical level
- G06F30/392—Floor-planning or layout, e.g. partitioning or placement
Landscapes
- Engineering & Computer Science (AREA)
- Computer Hardware Design (AREA)
- Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Architecture (AREA)
- Evolutionary Computation (AREA)
- Geometry (AREA)
- General Engineering & Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Oscillators With Electromechanical Resonators (AREA)
Abstract
The invention provides an anti-electromagnetic interference crystal oscillator resonant circuit, which comprises: and the feedback resistor and the amplifier are connected in parallel, wherein a first parallel node of the feedback resistor and the amplifier is connected to the input signal terminal through a first coaxial shielding metal ring, and a second parallel node of the feedback resistor and the amplifier is connected to the output signal terminal through a second coaxial shielding metal ring.
Description
Technical Field
The invention relates to the field of semiconductor manufacturing and the field of circuit design, in particular to an anti-electromagnetic interference crystal oscillator resonant tank circuit.
Background
The oscillation circuit with the crystal oscillator as the core has the advantages of accurate and stable working frequency, frequency only related to the progress of the selected crystal device and the like, thereby being widely applied to consumer electronics, military industry and communication chips such as clocks, monitors and the like. However, the performance of such an oscillating circuit depends not only on the crystal device, but also on the design of the resonant tank that cooperates with the crystal. Because the crystal device is generally externally connected and the resonant circuit is generally embedded in the chip, the designed resonant circuit is convenient to integrate. Electromagnetic interference (EMI) is an important parameter of the quality of the resonant tank of the crystal oscillator, and directly affects or limits the market application of products.
Generally, a method for reducing electromagnetic interference of a crystal oscillator resonant circuit is to increase the time of a rising edge and a falling edge of a clock signal, so as to reduce the voltage change rate in unit time, thereby reducing the radiation and conduction interference of the resonant circuit. However, this increases the speed and static power consumption of the product, and especially when the product requires multi-clock synchronization, it causes jitter and skew of signals, so that the product fails. Therefore, reducing the electromagnetic interference by this method sacrifices certain product performance.
Thus, it is desirable to provide a design for a crystal resonant tank circuit that reduces electromagnetic interference from the crystal resonant circuit without sacrificing product performance.
Disclosure of Invention
The technical problem to be solved by the invention is to provide a design scheme of a crystal oscillator resonant circuit capable of reducing electromagnetic interference of the crystal oscillator circuit under the condition of not sacrificing product performance, aiming at the defects in the prior art.
In order to achieve the above technical object, according to the present invention, there is provided an anti-electromagnetic interference crystal resonator circuit, including: and the feedback resistor and the amplifier are connected in parallel, wherein a first parallel node of the feedback resistor and the amplifier is connected to the input signal terminal through a first coaxial shielding metal ring, and a second parallel node of the feedback resistor and the amplifier is connected to the output signal terminal through a second coaxial shielding metal ring.
Preferably, the transconductance of the amplifier in the linear amplification region working state is between tens of microamperes/volt and 10 milliamperes/volt.
Preferably, the crystal oscillation frequency of the crystal oscillation resonant circuit is 32.768KHZ, and the feedback resistance is selected to be between 10-25M ohm.
Preferably, the crystal frequency of the crystal resonance loop circuit is 20MHz, and the feedback resistance is selected to be not less than 470K ohm.
Preferably, in the layout of the crystal oscillator resonant tank circuit, the coaxial shielding metal ring is composed of a bottom layer metal, a top layer metal, a same layer metal of the input and output metal line and a through hole correspondingly connecting the metal layers.
Preferably, in the layout of the crystal oscillator resonant tank circuit, the coaxial shielding metal ring is formed by combining a whole metal layer with a through hole.
Preferably, in the layout of the crystal oscillator resonant tank circuit, the coaxial shielding metal ring is wound around the input end and the output end of the amplifier by a narrow-width metal combined with a through hole.
Preferably, in a layout of the crystal oscillator resonant tank circuit, an input/output signal line of the amplifier is composed of preset metal wiring, side wall shielding layers are formed on two sides of the signal line by metal on the same layer, the distance between each side wall shielding layer and the signal line adopts the minimum design rule of a corresponding process node or is larger than the minimum design rule, and a flat metal layer is arranged at the bottom of the metal wiring of the signal line and is respectively connected with two sides of each side wall shielding layer through a through hole; and a flat metal layer is arranged on the top of the signal wire metal wiring and is respectively connected with the two sides of the side wall shielding layer through holes.
Preferably, in the layout of the crystal oscillator resonant tank circuit, the amplifier input and output signal line is composed of a predetermined metal wiring; the side wall shielding layers are formed by the same layer of metal on two sides of the signal line; the distance between the side wall shielding layer and the signal line adopts the minimum design rule of the corresponding process node or is larger than the minimum design rule, a flat metal layer is arranged at the bottom of the metal wiring of the side wall shielding layer and is connected with the side wall shielding layer through a through hole, the width of the flat metal layer meets the minimum design rule of the corresponding process node or is larger than the minimum design rule, and the flat metal layer alternately and spirally surrounds the output signal line.
According to the invention, the coaxial shielding metal layer surrounding signal line is realized on the feedback signal terminal of the crystal oscillator driving circuit through the layout design, so that the technical effect of reducing the electromagnetic interference EMI of the crystal oscillator is achieved.
Drawings
A more complete understanding of the present invention, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:
fig. 1 schematically shows a conventional crystal oscillator pierce oscillator circuit schematic.
Fig. 2 schematically shows an anti-electromagnetic interference crystal resonator tank circuit according to a preferred embodiment of the present invention.
Fig. 3 and 4 schematically show specific examples of the anti-electromagnetic interference crystal resonant tank circuit according to the preferred embodiment of the present invention.
It is to be noted, however, that the appended drawings illustrate rather than limit the invention. It is noted that the drawings representing structures may not be drawn to scale. Also, in the drawings, the same or similar elements are denoted by the same or similar reference numerals.
Detailed Description
In order that the present disclosure may be more clearly and readily understood, reference will now be made in detail to the present disclosure as illustrated in the accompanying drawings.
Fig. 1 schematically shows a conventional crystal oscillator pierce oscillator circuit schematic. The bold line box 100 is embedded in the chip internal resonant tank. The input signal terminal OCS _ IN and the output signal terminal OSC _ OUT are 2 signal terminals of a feedback loop formed by the resonant tank and the crystal oscillator. Those skilled IN the art familiar with the principles of semiconductor devices will readily understand that after the oscillation of the inductor crystal oscillator starts, sine waves with opposite phases are generated on the input signal terminal OSC _ IN and the output signal terminal OSC _ OUT, and the alternating current will radiate an electric field outwards.
Fig. 2 schematically shows an anti-electromagnetic interference crystal resonator tank circuit according to a preferred embodiment of the present invention.
As shown in fig. 2, the anti-electromagnetic interference crystal resonant tank circuit according to the preferred embodiment of the present invention comprises: parallel feedback resistor RFAnd an amplifier Inv in which a feedback resistor RFA first parallel node connected to the amplifier Inv is connected to the input signal terminal OSC _ IN and the feedback resistor R via a first coaxial shield coil L1FThe second parallel node with the amplifier Inv is connected to the output signal terminal OSC _ OUT via the second coaxial shield coil L2.
Preferably, the transconductance of the amplifier Inv in the linear amplification region operating state is between several tens of microamperes/volt and 10 milliamperes/volt.
Preferably, the feedback resistance is selected to be between 10-25M ohm when the crystal oscillation frequency is 32.768 KHZ; the feedback resistance is selected to be not less than 470K ohms when the crystal frequency is 20 MHz.
Fig. 3 and 4 schematically show specific examples of the anti-electromagnetic interference crystal resonant tank circuit according to the preferred embodiment of the present invention.
Preferably, the coaxial shielding metal ring is composed of a bottom layer metal, a top layer metal, a same layer metal of the input and output metal line and a through hole correspondingly connecting the metal layers.
Preferably, the coaxial shield metal ring is formed of a single piece of metal layer in combination with VIAs VIA, or the coaxial shield metal ring is wound around the amplifier input and output terminals with narrow width metal in combination with VIAs VIA.
In one embodiment, for example, in the layout of the crystal resonance loop circuit, the amplifier input/output signal line is made of a predetermined metal clothThe signal line is composed of a line Mx, the two sides of the signal line are provided with side wall shielding layers formed by the same layer of metal, the distance between each side wall shielding layer and the corresponding signal line adopts the minimum design rule of the corresponding process node or is larger than the minimum design rule, and the bottom of the metal wiring of the signal line is provided with a flat metal layer MX-1The side wall shielding layers are respectively connected with the two sides of the side wall shielding layer through holes VIA; the top of the signal wire metal wiring is provided with a flat metal layer MX+1Through VIA VIA+1And the two sides of the side wall shielding layer are respectively connected.
In another specific embodiment, for example, in the layout of the crystal resonance loop circuit, the amplifier input-output signal line is constituted by a predetermined metal wiring Mx; the side wall shielding layers are formed by the same layer of metal on two sides of the signal line; the space between the side wall shielding layer and the signal line adopts the minimum design rule of the corresponding process node or is larger than the minimum design rule, and a flat metal layer M is arranged at the bottom of the metal wiring of the side wall shielding layerX-1And the side wall shielding layer is connected with the through hole VIA, the width of the flat metal layer meets the minimum design rule or is more than the minimum design rule of the corresponding process node, and the flat metal layer M is arranged at the bottom of the metal wiring of the side wall shielding layerX+1Through VIA VIA+1The width of the flat metal layer meets the minimum design rule or is more than the minimum design rule of the corresponding process node, and the flat metal layer M is connected with the side wall shielding layerX-1And MX+1Alternately, spirally surrounding the output signal line.
Compared with a conventional resonant circuit, the coaxial shielding metal layer is designed on the outer ring of the signal terminal connecting line of the feedback circuit. It will be appreciated that the coil inhibits alternating current from radiating an electric field outwardly. Meanwhile, the circuit plays a certain role in inhibiting the peak current generated when the circuit of the Pierce oscillator is turned on and off.
According to the invention, the coaxial shielding metal layer is arranged on the feedback signal terminal of the crystal oscillator driving circuit to surround the signal metal lead through the layout design, so that the technical effect of reducing the electromagnetic interference (EMI) of the crystal oscillator is achieved.
The electromagnetic interference of the crystal oscillator needs to meet the requirements of electronic product specifications such as EN55022, and is generally required to be less than 50 dBuV/m. The common crystal oscillator has an out-of-specification phenomenon at a specific frequency point. When general products are applied, methods such as connecting magnetic beads in series on pins outside the products are needed to solve the problem, and therefore the universality of the products is limited. Tests show that after the circuit and the layout design of the invention are used, the electromagnetic interference of the crystal oscillator is obviously reduced, and the EMI is reduced by 10dB at different frequency points, which all meet the specification.
In addition, it should be noted that the terms "first", "second", "third", and the like in the specification are used for distinguishing various components, elements, steps, and the like in the specification, and are not used for indicating a logical relationship or a sequential relationship between the various components, elements, steps, and the like, unless otherwise specified or indicated.
It is to be understood that while the present invention has been described in conjunction with the preferred embodiments thereof, it is not intended to limit the invention to those embodiments. It will be apparent to those skilled in the art from this disclosure that many changes and modifications can be made, or equivalents modified, in the embodiments of the invention without departing from the scope of the invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention are still within the scope of the protection of the technical solution of the present invention, unless the contents of the technical solution of the present invention are departed.
It is to be further understood that the present invention is not limited to the particular methodology, compounds, materials, manufacturing techniques, uses, and applications described herein, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention. It must be noted that, as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "an element" means a reference to one or more elements and includes equivalents thereof known to those skilled in the art. Similarly, as another example, reference to "a step" or "an apparatus" means a reference to one or more steps or apparatuses and may include sub-steps as well as sub-apparatuses. All conjunctions used should be understood in the broadest sense. Thus, the word "or" should be understood to have the definition of a logical "or" rather than the definition of a logical "exclusive or" unless the context clearly dictates otherwise. Structures described herein are to be understood as also referring to functional equivalents of such structures. Language that can be construed as approximate should be understood as such unless the context clearly dictates otherwise.
Moreover, implementation of the method and/or system of embodiments of the present invention may include performing the selected task manually, automatically, or in combination. Moreover, the actual instrumentation and equipment according to embodiments of the method and/or system of the present invention may utilize an operating system to accomplish several selected tasks either in hardware, software, or a combination thereof.
Claims (6)
1. An anti-electromagnetic interference crystal oscillator resonant tank circuit, comprising: the circuit comprises a feedback resistor and an amplifier which are connected in parallel, wherein a first parallel node of the feedback resistor and the amplifier is connected to an input signal terminal through a first coaxial shielding metal ring, a second parallel node of the feedback resistor and the amplifier is connected to an output signal terminal through a second coaxial shielding metal ring, and the coaxial shielding metal ring surrounds the input signal terminal or the output signal terminal so as to reduce the electromagnetic interference of the crystal oscillator.
2. The anti-electromagnetic interference crystal oscillator resonant tank circuit as recited in claim 1, wherein the transconductance of the amplifier in the linear amplification region operating state is between several tens of microamperes/volt and 10 milliamperes/volt.
3. The anti-EMI crystal resonator loop circuit of claim 1 or 2, wherein the crystal frequency of the crystal resonator loop circuit is 32.768KHZ, and the feedback resistance is selected to be between 10-25M ohms.
4. The anti-electromagnetic interference crystal resonant tank circuit according to claim 1 or 2, wherein the crystal frequency of the crystal resonant tank circuit is 20MHz, and the feedback resistance is selected to be not less than 470K ohms.
5. The anti-electromagnetic interference crystal oscillator resonant circuit according to claim 1 or 2, wherein in a layout of the crystal oscillator resonant circuit, the input and output signal lines of the amplifier are formed by predetermined metal wiring, the same layer of metal is arranged on both sides of the signal line to form a side wall shielding layer, the distance between the side wall shielding layer and the signal line adopts the minimum design rule of the corresponding process node or is larger than the minimum design rule, and the bottom of the metal wiring of the signal line is provided with a flat metal layer which is respectively connected with both sides of the side wall shielding layer through a through hole; and a flat metal layer is arranged on the top of the signal wire metal wiring and is respectively connected with the two sides of the side wall shielding layer through holes.
6. The anti-electromagnetic interference crystal oscillator resonance circuit according to claim 1 or 2, characterized in that in a layout of the crystal oscillator resonance circuit, the amplifier input and output signal line is constituted by a predetermined metal wiring; the side wall shielding layers are formed by the same layer of metal on two sides of the signal line; the distance between the side wall shielding layer and the signal line adopts the minimum design rule of the corresponding process node or is larger than the minimum design rule, a flat metal layer is arranged at the bottom of the metal wiring of the side wall shielding layer and is connected with the side wall shielding layer through a through hole, the width of the flat metal layer meets the minimum design rule of the corresponding process node or is larger than the minimum design rule, and the flat metal layer alternately and spirally surrounds the output signal line.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610924231.0A CN106503338B (en) | 2016-10-24 | 2016-10-24 | Anti-electromagnetic interference crystal oscillator resonant circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610924231.0A CN106503338B (en) | 2016-10-24 | 2016-10-24 | Anti-electromagnetic interference crystal oscillator resonant circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106503338A CN106503338A (en) | 2017-03-15 |
| CN106503338B true CN106503338B (en) | 2020-06-16 |
Family
ID=58318554
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610924231.0A Active CN106503338B (en) | 2016-10-24 | 2016-10-24 | Anti-electromagnetic interference crystal oscillator resonant circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106503338B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112115671A (en) * | 2020-09-14 | 2020-12-22 | 纳瓦电子（上海）有限公司 | Circuit structure for improving electromagnetic radiation of clock signal end of processor and forming method thereof |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105552075A (en) * | 2016-01-22 | 2016-05-04 | 成都芯源系统有限公司 | Semiconductor device for reducing parasitic inductance of system loop |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100379440B1 (en) * | 2000-02-16 | 2003-04-10 | 엘지전자 주식회사 | method for fabricating of microwave resonator |
| JP2009200747A (en) * | 2008-02-20 | 2009-09-03 | Nippon Dempa Kogyo Co Ltd | Constant temperature structure of crystal resonator and constant temperature type crystal oscillator using the same |
| WO2010104682A2 (en) * | 2009-03-10 | 2010-09-16 | Osram Sylvania Inc. | Dielectric-loaded field applicator for ehid lamps and ehid lamp assembly containing same |
| CN101907653B (en) * | 2010-06-25 | 2014-02-19 | 中国电力科学研究院 | Signal acquisition and transmission device for high-voltage DC transmission converter valve |
| CN102298108B (en) * | 2011-05-25 | 2013-11-06 | 重庆大学 | Impact characteristic simulation test apparatus of earthing device and method thereof |
| CN109712946B (en) * | 2013-03-29 | 2021-01-19 | 日月光半导体制造股份有限公司 | Semiconductor package |
| CN103310037B (en) * | 2013-04-28 | 2016-05-04 | 上海华力微电子有限公司 | A kind of method of setting up layout design rules detection file verification shape library |
| CN103281048B (en) * | 2013-06-14 | 2016-04-20 | 中国科学院半导体研究所 | A kind of micromechanical resonator and preparation method thereof |
| CN204013481U (en) * | 2014-08-22 | 2014-12-10 | 无锡华润矽科微电子有限公司 | Realize the circuit structure that low-voltage crystal oscillator drives |
| CN105634409A (en) * | 2014-11-16 | 2016-06-01 | 陕西亚泰电器科技有限公司 | Error detector for electronic watch |
-
2016
- 2016-10-24 CN CN201610924231.0A patent/CN106503338B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105552075A (en) * | 2016-01-22 | 2016-05-04 | 成都芯源系统有限公司 | Semiconductor device for reducing parasitic inductance of system loop |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106503338A (en) | 2017-03-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6683719B2 (en) | Apparatus and method for current sensor | |
| US9773607B2 (en) | Coil with variable inner diameter and electronic module made from the coil | |
| EP0880150A2 (en) | Printed wiring board | |
| JP2970660B1 (en) | Printed board | |
| US9312832B2 (en) | High power filter with single adjust for multiple channels | |
| US20150173256A1 (en) | Emi suppression technique using a transmission line grating | |
| CN106503338B (en) | Anti-electromagnetic interference crystal oscillator resonant circuit | |
| US9866173B2 (en) | Coupling structure for inductive device | |
| US9735793B2 (en) | Low-power clock repeaters and injection locking protection for high-frequency clock distributions | |
| US9089043B2 (en) | Device for attenuating propagation and reception of electromagnetic interference for a PCB-chassis structure | |
| JP2001326432A (en) | Connection structure of printed wiring board and cable, and electronic equipment | |
| JP4696628B2 (en) | Electric circuit and noise suppression method | |
| JP2003283177A (en) | Radiation noise reduction apparatus for electronic device | |
| JP2013141097A (en) | High frequency module and electronic apparatus using the same | |
| US10418940B2 (en) | Radio frequency interference mitigation in crystal oscillator circuitry | |
| CN210742385U (en) | Crystal oscillator frequency measuring system | |
| Garcia-Mora et al. | Filter design methodology for low noise power domains in datacenter platforms | |
| JP2001203434A (en) | Printed wiring board and electrical apparatus | |
| US20130229313A1 (en) | Electronic apparatus | |
| Breed | Fundamentals of passive component behavior at high frequencies | |
| US20050064923A1 (en) | Mobile communication devices having high frequency noise reduction and methods of making such devices | |
| US20030048157A1 (en) | Molded common mode ferrite filter for electronic sensors | |
| CN116781094A (en) | Electronic device and method for reducing power consumption of signal transmission in electronic device | |
| JP2001237584A (en) | Electronic device, manufacturing method thereof, and communication apparatus using it | |
| Alamin et al. | Ferrite Beads Basic Operations and Key Parameters |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |