CN104993794B - A kind of high precision numerical control LC oscillators using inductance tap - Google Patents
A kind of high precision numerical control LC oscillators using inductance tap Download PDFInfo
- Publication number
- CN104993794B CN104993794B CN201510363970.2A CN201510363970A CN104993794B CN 104993794 B CN104993794 B CN 104993794B CN 201510363970 A CN201510363970 A CN 201510363970A CN 104993794 B CN104993794 B CN 104993794B
- Authority
- CN
- China
- Prior art keywords
- inductance
- tap
- capacitor array
- capacitance
- oscillator
- 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
Landscapes
- Inductance-Capacitance Distribution Constants And Capacitance-Resistance Oscillators (AREA)
Abstract
The invention discloses a kind of high precision numerical control LC oscillators using inductance tap, which is characterized in that the setting position selection tap among the inductance of traditional LC oscillator, and another switched capacitor array is accessed as fine tuning capacitor array at tap.Tap among inductance can select one or a pair of of tap.When selecting a tap, fine tuning capacitor array is connected on tap terminals and inductance one end；When a pair of of tap of selection, fine tuning capacitor array is connected on two tap terminals.The present invention can realize higher frequency accuracy under limited position of minimum capacitance.
Description
Technical field
The invention belongs to technical field of integrated circuits, are related to a kind of digital controlled oscillator, and in particular to a kind of to be taken out using inductance
The digital control LC oscillator of head.
Background technology
Phaselocked loop is one of core circuit of contemporary electronic systems, is most common frequency source.Integrated circuit
The development of (Integrated Circuits, IC) technology so that digitalized locked phase loop technique is possibly realized.Compared to mould
Intend phaselocked loop, the characteristic of digital phase-locked loop is influenced smaller by technique, voltage and temperature fluctuation, there is better stability.
Digital phase-locked loop controls oscillator using digital code, and output frequency is continuous unlike voltage controlled oscillator
Value can only be a series of corresponding discrete frequencies values of different control codes.In digital phase-locked loop, these discrete frequency values and institute
There is the quantization errors of error, i.e. digital controlled oscillator between the frequency needed.These quantization errors can introduce additionally in the loop
Quantizing noise, the final frequency for the phaselocked loop that is finally added to, cause export phase noise deterioration.Therefore, digital controlled oscillator is defeated
The frequency accuracy gone out is higher, and quantization error is also just smaller, so as to which the influence to phase noise is also just smaller.
Fig. 1 is typical LC oscillator (LC Oscillator, hereinafter referred to as LC oscillators), by inductance capacitance
The resonant network and positive feedback amplifying circuit of composition are formed, and frequency of oscillation is represented by：
Wherein, L0And C0For the inductance and capacitance of resonant network, CPFor parasitic capacitance.By changing inductance L0Or capacitance C0
The frequency of oscillation of oscillator can be adjusted.In general, inductance value is difficult to accurately control and adjusts, therefore electric in digital controlled oscillator
Hold C0Generally realize that frequency is adjusted by switched capacitor array.It cannot yet with achievable capacitance in integrated circuit technology
Infinitely small, the capacitance accuracy of switching capacity switching is limited, and the frequency accuracy adjusted is also limited.Such as one
2.4GHz oscillators, typical inductance capacitance value is respectively 2nH and 2.2pF.And provided in a typical 180nm techniques
For minimum capacity in 10fF magnitudes, often increasing or decreasing a capacitance can make frequency of oscillation change 5.4MHz, such frequency accuracy
It is difficult to the requirement for meeting phaselocked loop.
The prior art improves the precision of digital controlled oscillator often through switched capacitor array is improved, and such as utilizes the string of capacitance
Parallel relationship is to obtain smaller capacitance.Although precision can be improved several times by these technologies, integrated circuit work is still limited by
The minimum capacity that skill can be provided also increases the design complexities of capacitor array.
The content of the invention
For the precision problem of digital controlled oscillator, the present invention proposes a kind of digital control LC oscillator using inductance tap,
So as under limited position of minimum capacitance, realize higher frequency accuracy.
To achieve the above object, the technical solution adopted by the present invention is as follows：
A kind of high precision numerical control LC oscillators using inductance tap, which is characterized in that in the inductance of traditional LC oscillator
Intermediate setting position selection tap, and another switched capacitor array is accessed as fine tuning capacitor array at tap.
Further, the tap among inductance can select one or a pair of of tap.When selecting a tap, fine tuning electricity
Hold array and be connected on tap terminals and inductance one end；When a pair of of tap of selection, fine tuning capacitor array is connected on two tap terminals.The electricity
Sense can be any type of inductance, including square, polygon, individual pen, multi-turn, single-layer metal or laminated inductance.
Further, the position of the tap determines the frequency accuracy of digital controlled oscillator, is set according to frequency accuracy requirement
The tap position that meter and calculation below determine.
Fig. 2 is using schematic diagram during a pair of of tap, in the inductance L of resonant network0Middle carry out tap, two taps are by inductance
It is divided into L1、L2And LTThree parts, i.e. L0=L1+L2+LT.If the fine tuning capacitor array capacitance being inserted between inductance tap is CT.Then its
Frequency of oscillation can approximate representation be
Wherein β=LT/L0.It can be seen that capacitance C0And CTIt is upper to change identical capacitance, final frequency of oscillation variable quantity
Differ β2.After adding in tap, the frequency accuracy of digital controlled oscillator improves 1/ β2Times.
During using a tap, inductance is divided into L by tap1And LTTwo parts, then L0=L1+LT, β=LT/L0, still can be with
Tap position is determined according to formula (2).
The distance of tap between shortening fine tuning capacitor array, that is, reduce the inductance L between tapT, so as to reduce β, can improve
The frequency accuracy of digital controlled oscillator.
Further, the coarse adjustment of the digital controlled oscillator and fine tuning capacitor array can be by any form switching capacity list
The array of member composition.Capacitance can also select metal capacitive plate in CMOS technology (MIM capacitor or MOM capacitor), polysilicon capacitance
(PIP capacitor) or Metal-oxide-semicondutor capacitance (mos capacitance).
Further, the negative resistance circuit of the digital controlled oscillator or positive feedback network can in any form, active device
It can also MOS transistor or triode etc..
The present invention improves the frequency accuracy of digital controlled oscillator using inductance tap.With existing high precision numerical control oscillator
Scheme is compared, the advantage of the invention is that：
1) frequency accuracy is high：This programme can be shaken numerical control by adjusting the ratio of tap inductor and entire differential inductance
The frequency accuracy for swinging device improves 1~2 order of magnitude；
2) it is simple in structure：In traditional digital controlled oscillator structure, this programme only adds in one in its inductance tap position
Traditional switched capacitor array, the capacitance series and parallel structure complicated without other or digital-to-analog converter structures；
3) flexible design：In the present invention, such as to continue to improve the frequency accuracy of digital controlled oscillator, can select to improve capacitance
The precision of array can also select to change tap position.So as to obtain good compromise in technique limitation and designed reliability.
4) it is low to technological requirement：This programme is low to capacitance accuracy requirement, can also be obtained in traditional low cost process
Good frequency accuracy significantly reduces and is designed and manufactured as this；
5) can be combined with other High-precision schemes：It is difficult to effectively tie between existing high precision numerical control oscillator scheme
It closes.And in the fine tuning capacitor array of this programme, existing High-precision scheme can be flexibly used, to further improve digital controlled oscillator
Precision.
Description of the drawings
Fig. 1 is a kind of digital controlled oscillator exemplary block diagram based on inductor-capacitor；
Fig. 2 is the inductance capacitance resonant network schematic diagram for adding in tap and fine tuning array；
Fig. 3 is a kind of example of the digital controlled oscillator based on inductance tap；
Fig. 4 is a kind of specific implementation of inductance tap in CMOS technology；
Fig. 5 is the switching capacity cellular construction figure employed in example of the present invention.
Specific embodiment
Below by specific embodiment, and coordinate attached drawing, the present invention is described in detail.
Fig. 3 is the concrete example of the present invention, is realized in CMOS180nm techniques.Its basic structure and traditional inductance-
Capacitor oscillator is similar.The NMOS and a pair of of PMOS tube that negative resistance circuit is coupled by a pair of cross are formed.NMOS tube NM1 and NM2 ruler
Very little is 6*6 μm/250nm, PM1 and PM2 sizes are 16*12 μm/250nm.In addition, the source in NMOS tube adds one group of resistance
Array adjusts the operating current of oscillator by adjusting different tail resistance values.Electric resistance array is by 8 96 ohm of polysilicon
Resistance is formed.
Inductor-capacitor network proposed in the present invention unlike traditional oscillators.As shown in figure 4, in CMOS works
The inductance of oscillator has been customized in skill using top layer thickness metal Metal6 and time top-level metallic Metal5.Two have been selected in this example
Square inductance, 280 μm of internal diameter are enclosed, line width is 12 μm, 1.5 μm of line spacing.Inductance is drawn from secondary top-level metallic Metal5, is drawn
Point is OP and ON.Tapping point is located at about 109.5 μm of inductance central point both sides, is drawn using top-level metallic Metal6, leading point
For TAPP and TAPN.
Coarse adjustment capacitor array and fine tuning capacitor array are made of identical switching capacity unit.Each Unit selection is as schemed
Traditional structure shown in 5 is made of three switching transistors M0, M1, M2 and a pair of of MIM capacitor C1, C2.It is height in control signal
During level, all transistor turns, OP and ON direct-to-ground capacitance values are approximately equal to C1/C2；When control signal is low level, own
Transistor cutoff, OP and ON direct-to-ground capacitance are approximately the parasitic capacitance C over the ground of three source transistor drain terminalsP.Therefore believe in control
During number saltus step, capacitor cell can convert capacitance Δ C=C1/C2-CP。
In this example, M0, M1, M2 size be respectively 7 μm/180nm, 1 μm/180nm, 1 μm/180nm.Coarse adjustment capacitance battle array
Row are digital control by 8bit, totally 256 switching capacity units, and MIM capacitor size is 4 μm x6 μm, capacitance about 23.3fF, slightly
Adjust capacitor array minimum capacity variation about 18.3fF.Fine tuning capacitor array is digital control by 9bit, totally 512 switching capacity lists
Member, MIM capacitor size are 4 μm x4 μm, capacitance about 15.5fF, fine tuning capacitor array minimum capacity variation about 7.5fF.
Coarse adjustment capacitor array is connected between Fig. 4 inductance OP and ON, and fine tuning electric inductance array is connected on the TAPP and TAPN of Fig. 4 inductance
Between.Emulation and test result show that in CMOS180nm techniques, structure of the invention can put forward digital controlled oscillator precision
Height improves about 120 times to 7.6kHz compared to traditional structure.
The above embodiments are merely illustrative of the technical solutions of the present invention rather than is limited, the ordinary skill of this field
Personnel can be modified or replaced equivalently technical scheme, without departing from the spirit and scope of the present invention, this
The protection domain of invention should be subject to described in claim.
Claims (6)
1. a kind of high precision numerical control LC oscillators using inductance tap, which is characterized in that in the resonant network of LC oscillators
Inductance setting position a pair of of tap is set, a switched capacitor array, i.e. fine tuning capacitor array are accessed to tap by this；Its
In, according to formulaThe position of the tap position is set；Wherein, f is digital control LC oscillator
Frequency, the inductance is divided into three parts by this to tap, and the inductance value of the three parts inductance is respectively L1、L2And LT, the electricity
The inductance value L of sense0=L1+L2+LT, LTFor the inductance value inductance part tap, β=LT/L0；CTFor the fine tuning capacitance battle array
The capacitance of row, C0For the capacitance of capacitor array in the resonant network.
2. digital control LC oscillator as described in claim 1, which is characterized in that the inductance for square inductance, polygon inductance,
Individual pen inductance, multi-turn inductance, individual layer inductance or laminated inductance.
3. digital control LC oscillator as described in claim 1, which is characterized in that the capacitor array can select metallic plate electric
Appearance, polysilicon capacitance or Metal-oxide-semicondutor capacitance.
4. digital control LC oscillator as described in claim 1, which is characterized in that the negative resistance circuit of the oscillator or positive feedback net
Network can select MOS transistor, triode.
5. a kind of high precision numerical control LC oscillators using inductance tap, which is characterized in that in the resonant network of LC oscillators
Inductance setting position one tap is set, and a switched capacitor array, i.e. fine tuning are accessed in the one end for passing through the tap and the inductance
Capacitor array；Wherein, according to formulaThe position of the tap position is set；Wherein, f is number
The frequency of LC oscillators is controlled, which is divided into two parts by the inductance, and the inductance value of two parts inductance is respectively L1With
LT, the inductance value L of the inductance0=L1+LT, β=LT/L0；CTFor the capacitance of the fine tuning capacitor array, C0For the resonant network
The capacitance of middle capacitor array, LTFor the inductance value with the fine tuning capacitor array parallel connection part.
6. digital control LC oscillator as claimed in claim 5, which is characterized in that the inductance for square inductance, polygon inductance,
Individual pen inductance, multi-turn inductance, individual layer inductance or laminated inductance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510363970.2A CN104993794B (en) | 2015-06-26 | 2015-06-26 | A kind of high precision numerical control LC oscillators using inductance tap |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510363970.2A CN104993794B (en) | 2015-06-26 | 2015-06-26 | A kind of high precision numerical control LC oscillators using inductance tap |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104993794A CN104993794A (en) | 2015-10-21 |
| CN104993794B true CN104993794B (en) | 2018-05-22 |
Family
ID=54305559
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510363970.2A Active CN104993794B (en) | 2015-06-26 | 2015-06-26 | A kind of high precision numerical control LC oscillators using inductance tap |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104993794B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108199687B (en) * | 2018-01-16 | 2021-06-01 | 重庆西南集成电路设计有限责任公司 | Transconductance linearization broadband LC type voltage-controlled oscillator and adjustable capacitor array circuit |
| US11609128B2 (en) * | 2019-12-10 | 2023-03-21 | Wiliot, LTD. | Single layer LC oscillator |
| CN112968670B (en) * | 2021-02-01 | 2022-11-08 | 电子科技大学 | Miniaturized discrete coupling multicore oscillator |
| CN116886046B (en) * | 2023-09-07 | 2023-11-17 | 南京米乐为微电子科技有限公司 | Voltage-controlled oscillating circuit |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102420605A (en) * | 2010-09-24 | 2012-04-18 | 剑桥硅无线电有限公司 | Lc oscillator |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009296375A (en) * | 2008-06-05 | 2009-12-17 | Toshiba Corp | Digitally controlled oscillator and phase-locked loop circuit employing the same |
-
2015
- 2015-06-26 CN CN201510363970.2A patent/CN104993794B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102420605A (en) * | 2010-09-24 | 2012-04-18 | 剑桥硅无线电有限公司 | Lc oscillator |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104993794A (en) | 2015-10-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104993794B (en) | A kind of high precision numerical control LC oscillators using inductance tap | |
| CN105190880B (en) | Circuit and method for multi-mode filter | |
| US20160056762A1 (en) | Split Transformer Based LC-Tank Oscillator | |
| US10211779B2 (en) | Boosting varactor capacitance ratio | |
| KR101667847B1 (en) | Antenna tuning circuit, method for tuning an antenna, antenna arrangement and method for operating the same | |
| TW201044791A (en) | Clock, frequency reference, and other reference signal generator with frequency stability over temperature variation | |
| CN106712736B (en) | Adjustable passive network of broadband | |
| US11749710B2 (en) | Adjustable multi-turn magnetic coupling device | |
| US10833685B1 (en) | Linearized wide tuning range oscillator using magnetic balun/transformer | |
| EP3093989B1 (en) | Inductor capacitor tank for resonator | |
| TW494615B (en) | A band-switched integrated voltage controlled oscillator | |
| US8072280B2 (en) | Voltage-controlled oscillator | |
| CN104467839B (en) | The circuit for generating and distributing for clock | |
| CN1794567B (en) | Voltage controlled oscillator with analogue and digital control | |
| KR101196842B1 (en) | Apparatus for controlling LC circuit using spiral inductor | |
| JP4310661B2 (en) | IC for tuning circuit and receiving circuit using the same | |
| CN106505948A (en) | Lofty tone frequency division resolution digital controlled oscillator based on tail capacitance tuning structure | |
| CN103580607A (en) | Voltage-controlled oscillator circuit | |
| CN209375582U (en) | A kind of novel switched capacitor trims digital controlled oscillator | |
| CN108886413B (en) | Voltage transformation device, circuit and method of voltage control oscillator for wireless sensor | |
| CN104333379B (en) | A kind of cmos vco of High Linear frequency-tuning range | |
| CN107346960B (en) | Low-offset operational amplifier based on active load adjustment | |
| CN114586279A (en) | Oscillator circuit | |
| CN114337599B (en) | Variable-bandwidth active RC filter and RC array setting method thereof | |
| CN111181491A (en) | Clock generating circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |