CN101527566A - Current device for phase-locked loop and method thereof - Google Patents

Abstract

The invention provides a current device for a phase-locked loop and a method thereof. The current device can adjust the central oscillation frequency of a voltage controlled oscillator to protect a compensated central oscillation frequency from the influences of treatment, voltage and temperature actually and can cover a primary frequency oscillation range by using a small KVOC value. In addition, the current device of the invention can also be used in a charge pump to allow the current Icp of the charge pump to be adjusted according to a gain KVOC of the voltage controlled oscillator to reduce the influences of the treatment, the voltage and the temperature on the Icp*KVCO.

Description

Be applied to the current device and the method thereof of phase-locked loop

Technical field

The present invention is about current device, particularly about a kind of current device that is applied to the phase-locked loop.

Background technology

Fig. 1 is the framework calcspar of known phase-locked loop.With reference to figure 1, phase-locked loop 100 comprises: phase detectors (phase detector) 102, one charge pumps (charge pump) 104, one low pass filter (low-pass filter, LPF) 106, one voltage-controlled oscillator (VCO) (voltage-controlled oscillator, VCO) 110 and one frequency eliminator (frequency divider) 108.Phase-locked loop 100 is when initial condition, phase detectors 102 compare the phase difference (phase error) of reference clock and feedback clock earlier, after converting both phase difference relation to UP and two signals of DN then, deliver to charge pump 104 respectively, and charge pump 104 is controlled voltage V according to UP and DN two signals to export one _CtrlInput to voltage-controlled oscillator (VCO) 110.Charge pump 104 is done the action of charging (charge) or discharge (discharge) to the resistance capacitance of low pass filter 106 (figure does not show) via the control of UP and two signals of DN, then, the control voltage V that produced by 104 pairs of low pass filter 106 charge or discharge of charge pump of voltage-controlled oscillator (VCO) 110 _CtrlTo produce an output clock.Then, frequency eliminator 108 carries out frequency elimination with this output clock, offers the comparison that phase detectors 102 are made phase difference to produce feedback clock, circulation running so always, when the frequency of feedback clock and reference clock was identical in fact with phase difference, phase-locked action was promptly finished in the phase-locked loop.

In the relevant application in phase-locked loop, frequency synthesizer (frequency synthesizer) and clock and datum recover (clock and data recovery for example, CDR) etc., voltage-controlled oscillator (VCO) and charge pump are in phase-locked time, being easier to be subjected to external environment influences, for example: processing, voltage and Temperature Influence.And the gain of voltage-controlled oscillator (VCO) (gain): K _VCO=d ω/dv=df/dv (wherein, ω is an angular frequency, and f is an operating frequency, and v is a voltage) is the desired value of a reference, bigger K _VCOValue can contain the variation of processing, voltage and temperature (process, voltage, temperature are hereinafter to be referred as PVT), on the contrary, and less K _VCOValue then can reduce the susceptibility to noise.

United States Patent (USP) the 5th, 064, No. 907 and the 6th, 326, the voltage-controlled oscillator (VCO) that is proposed for No. 855 belongs to out the compensation way of loop (open loop) framework, it does compensation at voltage current adapter (voltage-to-currentconverter), and offset current wherein is be directly proportional with absolute temperature (proportional to absolute temperature, electric current PTAT) basically.In addition, in November, 2005, people such as Hyung-Rok Lee (" A 1.2-V-only 900mW 10gb Ethernet transceiver and XAUIinterface with robust VCO tuning technique; " JSSC, Nov., 2005) a kind of voltage-controlled oscillator (VCO) with temperature compensation function is also proposed.

On the other hand, because high K _VCOThe voltage-controlled oscillator (VCO) of the single-frequency voltage response of value is responsive to noise, therefore has low K _VCOThe characteristic voltage-controlled oscillator (VCO) of the multisection type of value (multi-range or multi-band) voltage to frequency also is developed successively, is the voltage to frequency performance diagram with multisection type voltage-controlled oscillator (VCO) of two groups of input signals shown in Fig. 2 A.In June, 2005, people such as Nonis (" Modeling; Design and Characterization of a New Low-Jitter Analog DualTuning LC-VCO PLL Architecture; " IEEE Journal of Solid-state Circuits) a kind of continuous time of two loop adjustment (continuous time dual-loop tuning) methods is proposed, employing has the voltage-controlled oscillator (VCO) of two groups of input signals, the K of this voltage-controlled oscillator (VCO) _{VCO, f}, shown in Fig. 2 A, much smaller than known K with voltage-controlled oscillator (VCO) of one group of input signal _{VCO, S}Voltage-controlled oscillator (VCO) with two groups of input signals utilizes voltage V earlier _CDo coarse adjustment (coase), make this voltage-controlled oscillator (VCO) work in the wherein voltage to frequency characteristic curve an of the best, remake fine setting (fine) control, make (V _Finep-V _Finen) as far as possible near reference voltage (V _Refp-V _Refn), the result makes voltage-controlled oscillator (VCO) work in linear zone (K wherein _{VCO, f}And make the voltage to frequency characteristic curve of voltage-controlled oscillator (VCO) can maintain identical frequency output area definite value no better than).

Shown in Fig. 2 B the voltage to frequency performance diagram of two loop adjustment (discrete time dual loop) the multisection type voltage-controlled oscillator (VCO)s of another known discrete time, wherein, V _LBe minimum control voltage, V _HBe maximum controlling voltage, each voltage to frequency characteristic curve among the figure measures down at same parameter model (at the same processcorner), and, frequency between each voltage to frequency characteristic curve is overlapping (overlap) mutually, when circuit operates, the coarse adjustment of phase-locked loop is to utilize voltage-controlled oscillator (VCO) to work in the wherein voltage to frequency characteristic curve an of the best, and fine setting is in the voltage to frequency characteristic curve of above-mentioned the best, makes voltage-controlled oscillator (VCO) an optimum job.

Be shown in Fig. 2 C under different parameter models and different temperature, the voltage to frequency performance diagram of unistage type (single-band) voltage-controlled oscillator (VCO), shown in Fig. 2 C, the voltage to frequency characteristic curve that low temperature measured, K _VCOValue is big (or slope is bigger), and the voltage to frequency characteristic curve that high temperature measured, K _VCOBe worth less (or slope is less).Therefore, for the unistage type voltage-controlled oscillator (VCO), under identical operating frequency, big K _VCOThe voltage to frequency characteristic curve of value can correspond to less control voltage, and less K _VCOThe voltage to frequency characteristic curve of value can correspond to bigger control voltage.

In December, 2002, people such as Dally (" A Low-Power Multiplying DLL for Low-JitterMultigigahertz Clock Generation in Highly Integrated Digital Chips; " IEEEJournal of Solid-state Circuits) proposes a kind of adaptation bias voltage type (adaptive-biased) charge pump (figure does not show), be used in the phase-locked loop for the different disposal model with compensation K _VCOVariation, this charge pump is the control voltage V according to voltage-controlled oscillator (VCO) _CntlTo produce corresponding charge pump current Icp, make K _VCO* Icp does not more also drift about along with PVT.This is because voltage-controlled oscillator (VCO) is to keep identical output services frequency, less K _VCOThe voltage to frequency characteristic curve of value (or slope is less) needs bigger control voltage (shown in Fig. 2 C), and vice versa, so charge pump can be according to control voltage V _CntlProduce corresponding charge pump current with compensation K _VCOVariation.

Summary of the invention

One of purpose of the present invention is to provide a kind of current device that is applied to the phase-locked loop, can be initiatively according to K _VCOVariation, produce corresponding bucking voltage or offset current.

The present invention discloses a kind of current device, comprises: a bucking voltage produces a circuit and a current output unit.This bucking voltage produces circuit, is used for producing a bucking voltage, and this bucking voltage produces circuit and comprises: one first electric crystal receives a reference current to produce this bucking voltage; And a compensating unit, coupled in parallel is used for compensating this bucking voltage to this first electric crystal.Current output unit comprises at least one second electric crystal, and this electric crystal is used for according to this bucking voltage to export one first output current; Wherein, this second electric crystal and this first electric crystal form a current-mirror structure.

In conjunction with detailed description and the claim of following diagram, embodiment, will on address other objects and advantages of the present invention and be specified in after.

Description of drawings

Fig. 1 is the framework calcspar of a known phase-locked loop.

Shown in Fig. 2 A known multisection type voltage-controlled oscillator (VCO) with two groups of input signals, its voltage to frequency performance diagram.

It shown in Fig. 2 B the voltage to frequency performance diagram that the two loops of another known discrete time are adjusted the multisection type voltage-controlled oscillator (VCO).

Be shown in Fig. 2 C under different parameter models and different temperature, the voltage to frequency performance diagram of unistage type voltage-controlled oscillator (VCO).

Fig. 3 is the configuration diagram that voltage-controlled oscillator (VCO) is used an embodiment of current device of the present invention.

Fig. 4 A is the Organization Chart that bias voltage and bucking voltage produce an embodiment of circuit application current device of the present invention.

Fig. 4 B is the Organization Chart that delay element (delay cell) is used an embodiment of current device of the present invention.

Fig. 5 is the framework that voltage-controlled oscillator (VCO) is used current device of the present invention, under different parameters model and control voltage, and measured voltage to frequency characteristic curve graph of a relation.

Fig. 6 is the configuration diagram of an embodiment of charge pump applications current device of the present invention.

The figure number explanation:

100 phase-locked loops

102 phase detectors

104,600 charge pumps

106 low pass filters

108 frequency eliminators

110,300 voltage-controlled oscillator (VCO)s

300 voltage-controlled oscillator (VCO)s

310 bias voltages and bucking voltage produce circuit

320 ring-like oscillators

321～32N delay element

321a～32Na, 421,425 delay cells

321b～32Nb voltage-controlled current source

410 bucking voltages produce circuit

420 half replica biased generation circuit

423,630 voltage current adapters

620 current mirrors

M ₁～M ₅, M ₁₆The NMOS electric crystal

M ₆, M ₇, M ₁₃, M ₁₄, M ₁₅The PMOS electric crystal

Embodiment

Fig. 3 is the configuration diagram of an embodiment of voltage-controlled oscillator (VCO) of the present invention.With reference to figure 3, voltage-controlled oscillator (VCO) 300 comprises a bias voltage and bucking voltage produces circuit 310 and a N (N is the positive integer greater than 1) the ring-like oscillator in rank (ring oscillator) 320.Ring-like oscillator 320 comprises N delay element (delay cell) 321～32N, and each delay element comprises a current-control type (current-controlled) delay cell again, and (321a～32Na) and a voltage-controlled current source (current source) are (321b-32Nb).

Bias voltage and bucking voltage produce circuit and are used for producing a bias voltage V _BpTo offer all delay elements (321a～32Na), also produce a bucking voltage V simultaneously _CompTo offer all voltage-controlled current sources (32lb～32Nb).Circuit designers is according to the delay time T of each delay element and default concussion frequency f _OSC, be connected in series the ring-like oscillator on N rank, just f _OSC≡ 1/N * τ, wherein the exponent number N of ring-like oscillator is big more or delay time T is long more, the concussion frequency f _OSCJust low more.Ring-like oscillator in the present embodiment is because be differential-type (differential), so N can be odd number or even number, when N is even number, wherein positive-negative output end A+, the A-of the delay element of single order must reverse (inverted), be represented by dotted lines in the drawings, and when N was odd number, positive-negative output end A+, A-needn't reverse, and represented with solid line in the drawings.

Please refer to Fig. 4 A, Fig. 4 A is the Organization Chart that bias voltage and bucking voltage produce an embodiment of circuit application current device of the present invention, and bias voltage and bucking voltage produce circuit 310 and comprise bucking voltage generation circuit 410 and half replica biased generation circuit (half replica bias generator) 420.Bucking voltage produces circuit 410, is used for producing a bucking voltage V _Comp Bias generating circuit 420 comprises half a replica delay unit 421 and a voltage current adapter (V-to-I converter) 423.And bucking voltage produces an embodiment of circuit 410 and voltage current adapter 423 formations current device of the present invention.Wherein, voltage current adapter 423 comprises two NMOS electric crystal M ₁, M ₂, be used for respectively according to control voltage V _Cntl(being provided) and this bucking voltage V by charge pump _CompTo produce a Control current I _Cntl(=I _t+ I _c), half replica delay unit 421 then comprises two PMOS electric crystal M ₆, M ₇And NMOS electric crystal M ₅, according to Control current I _CntlProduce a bias voltage V _Bp

Suppose voltage V _BgAnd electric current I _BgAll be the amount of fixing, can not change that the present invention utilizes a compensation electric crystal M with PVT ₄Coupled in parallel is to electric crystal M ₃Follow the trail of electric crystal M ₁Change the variation that produces because of context PVT.As electric crystal M ₁The adjustment electric current I _tBecause of the PVT (K that diminishes _VCODiminish,

Diminish) time, electric crystal M flows through ₄Electric current I ₄(figure do not show) also diminish thereupon ( Diminish), at this moment, because of electric current I _BgFix, so the electric crystal M that flows through ₃Electric current I ₃(figure do not show) can increase, and then makes bucking voltage V _CompRise, because bucking voltage V _CompThe result who rises makes electric crystal M ₂The offset current I that is produced _C(electric crystal M also can rise thereupon ₃, M ₂Be current mirror (current mirror) framework), obtain whole Control current I at last _Cntl(=I _c+ I _t) constant result.Therefore, during context PVT change, offset current I _CCan be initiatively according to electric crystal M ₁Electric current I _tChange (or

Change) and change.Current mirror M ₃, M ₂With electric current I _BgWith electric crystal M ₄Output current I ₄Between difference between current amplify, to produce offset current I _C, electric crystal M just ₂Offset current $I_C=I_{\mathrm{bg}}-V_{\mathrm{bg}}*g_{m_4}*g_{m_2}/g_{m_3},$ Wherein, This variable can be followed the trail of electric crystal M ₁

Change (because context PVT change).Subsidiary one carries, and the producing method of offset current IC of the present invention is the design that belongs to out loop (open loop) framework.

On the other hand, if all are changed the combination that the signals that change all are considered as fixed value (constant) signal and a variable (variable) signal with PVT, for example:

Electric crystal M ₁Electric current $I_t=I_{\mathrm{const}1}+I_{\mathrm{var}1}=I_{\mathrm{<figure-callout\; id="1"\; label="const"\; filenames="A20081008208200141.png,A20081008208200162.png"\; state="\{\{state\}\}">const</figure-callout>}1}+{\mathrm{<figure-callout\; id="1"\; label="g\; m"\; filenames="A20081008208200141.png,A20081008208200162.png"\; state="\{\{state\}\}">g</figure-callout>}}_{m_{}}*V_{\mathrm{cntl}};$

Electric crystal M ₂Electric current $I_C=I_{\mathrm{const}2}-I_{\mathrm{var}2}=I_{\mathrm{const}2}+g_{m_2}*V_{\mathrm{const}};$

Then

Control current $I_{\mathrm{cntl}}=I_C+I_i=(I_{\mathrm{const}1}+I_{\mathrm{const}2})+(I_{\mathrm{var}1}-I_{\mathrm{var}2})$

$=(I_{\mathrm{const}1}+I_{\mathrm{const}2})+(g_{m_1}-\mathrm{\&alpha;}*g_{m_2})*V_{\mathrm{cntl}};$

Wherein, suppose V _Const=α * V _Cntl

The electric current I that the present invention utilizes energy gap reference circuits (bandgap voltage reference circuit) to be produced _BgSheet is used as Iconst2, voltage V _BgSheet is used as V _ConstSelection parameter alpha via suitable, the ((I just that can make the amount of change disappear each other _Var1-I _Var2)=0), only remaining fixing amount (=(I _Const1+ I _Const2)), therefore, at voltage V _Bg=voltage V _CntlThe time, Control current I _CntlIt all is a fixed value.From another perspective, electric crystal M ₄Output current I ₄Can follow the trail of electric current I _tVariation, all be to change (electric current I just in the same direction _tWhen becoming big, electric current I ₄Also become big), this moment is because electric current I _BgBe definite value, so electric crystal M ₃Output current I ₃Meeting and electric crystal M ₄Output current I ₄Be change in the other direction, then, again because of current mirror M ₃, M ₂Relation, also make offset current I _CWith electric current I ₃Also be equidirectional change (as electric crystal M ₃, M ₂When identical, I ₃=I _C), therefore, the result is offset current I _CWith electric current I _tChange in the opposite direction.

Please refer to Fig. 4 B, Fig. 4 B is the Organization Chart that delay element is used an embodiment of current device of the present invention, and (321～32N) comprise a current-control type delay cell 425 and a voltage current adapter 423 to each delay element.The voltage current adapter 423 same reception control voltage V that charge pump provided _CntlProduce this bucking voltage V that circuit 410 is provided with bucking voltage _CompTo produce Control current I _Cntl(=I _c+ I _t).Compare with the delay cell 423 of Fig. 4 A, delay cell 423 is the half of circuit of delay cell 425 just, and delay cell 425 is according to this Control current I _CntlWith bias voltage V _Bp, with two positive-negative input end V _I+, V _I-The reverse back of the clock signal of being imported is in positive-negative output end V _O+, V _O-Produce delay clock signals.And voltage current adapter 423 produces the embodiment that circuit 410 constitutes current device of the present invention with bucking voltage, and its operating principle and compensation principle are in above stated specification, and therefore this does not give unnecessary details in addition again.

Fig. 5 is the framework of the voltage-controlled oscillator (VCO) according to the present invention, under different parameters model and control voltage, and measured voltage to frequency characteristic curve graph of a relation.In embodiments of the invention, voltage-controlled oscillator (VCO) 300 utilizes bucking voltage to produce the framework of circuit 410, is target compensation with voltage current adapter 423 with current-control type delay cell 425, and elder generation is with voltage V behind power initiation _BgWith electric current I _BgA default respectively fixed value (V for example _Bg=0.45V, I _Bg=70 μ A), in the different parameters model with different PVT situations under, bucking voltage produces circuit 410 all can produce corresponding bucking voltage V _Comp, electric crystal M ₂Produce corresponding offset current I _C, and then adjust each voltage to frequency characteristic in the commotio cordis frequency, make each voltage to frequency characteristic in the commotio cordis frequency almost intersection in a bit, about V _Cntl=V _BgNear (as shown in Figure 5) of=0.45V.Compare with Fig. 2 C, can see that the characteristic middle commotio cordis frequency of three voltage to frequencies of Fig. 5 all is adjusted really or has moved.As control voltage V _CntlEqual voltage V _BgThe time, Control current I _CntlAlso definite value no better than, make three characteristic in the commotio cordis frequencies almost meet at same point (V _Cntl=V _Bg), middle commotio cordis frequency is difficult for changing with the change of PVT, so voltage-controlled oscillator (VCO) 300 can be with less K _VCOValue (or slope is less) contains identical operating frequency (operating frequency) or main concussion scope.Yet, V _BgAnd I _BgActual value can change according to the requirement of circuit designers for centre frequency, not with V _Bg=0.45V, I _Bg=70 μ A exceed.

Please refer to Fig. 6, Fig. 6 is the configuration diagram of an embodiment of charge pump applications current device of the present invention.Charge pump current I _CpSize can be according to different K _VCOAdjust, make I _Cp* K _VCOProduct is a definite value, and and then adjusts and control voltage V _Cntl Size.Charge pump 600 comprises a bucking voltage and produces circuit 410, a voltage current adapter 630, two electric crystal M ₁₅, M ₁₆An and current mirror 620.Wherein, electric crystal M ₁₅, M ₁₆Be used as two switches of being controlled by control signal UP, DN respectively, in order to control charging current I _CpAnd discharging current I ₁₄(electric crystal M flows through ₁₄Electric current) to electric charge delivery side of pump V _CntlCharging and discharging state.

(assumed temperature rises, K when context PVT change _VCOValue diminishes,

Diminish) time, electric crystal M flows through ₄Electric current I ₄(figure does not show) diminishes thereupon, at this moment, and because of electric current I _BgFix, so the electric crystal M that flows through ₃Electric current I ₃(figure do not show) can increase, and makes bucking voltage V _CompRise, and electric current I _C, I _Cp(because electric crystal M also rises thereupon ₃, M ₂, M ₁Be the current mirror framework), last, electric crystal M flows through ₁₃, M ₁₄Electric current I ₁₃, I ₁₄(figure does not show) rises synchronously, so I _Cp* K _VCOProduct (just phase-locked loop open loop gain) is almost constant.Being different from known techniques is according to control voltage (V _Cntl) producing corresponding charge pump current, charge pump of the present invention is according to K _VCO(or ) change adjust charge pump current I _Cp, and then adjust control voltage V _Cntl, therefore, charge pump of the present invention not only is applicable to the voltage-controlled oscillator (VCO) with unistage type voltage to frequency characteristic curve (single band), also be fit to the to have multisection type voltage to frequency characteristic curve voltage-controlled oscillator (VCO) of (multi band at the same corner).If derive with the mathematics formula:

I _cp*K _VCO＝(I _cp，const+ΔI _cp)*(K _VCO，const-ΔK _VCO)

＝I _cp，const*K _VCO，const+K _VCO，const*ΔI _cp-ΔK _VCO*I _cp，const-ΔK _VCO*ΔI _cp

Because Can follow the trail of K _VCOVariation, (K _{VCO, const}* Δ I _Cp-Δ K _VCO* I _{Cp, const}) zero no better than, moreover, Δ K _VCO* Δ I _CpProduct value, go up much smaller than I relatively _{Cp, const}* K _{VCO, const}Product value, so I _Cp* K _VCOProduct value can be considered constant.

According to current device and the method that embodiments of the invention provided, can select one according to designer's demand and be applied in voltage-controlled oscillator (VCO) or the charge pump, perhaps the two uses simultaneously and also can.If be applied to voltage-controlled oscillator (VCO), then can compensate the middle commotio cordis frequency of voltage-controlled oscillator (VCO), if be applied in the charge pump, then can compensate piezoelectricity stream I _Cp,, then can compensate I if use the two simultaneously _Cp* K _VCO, make I _Cp* K _VCOProduct is a definite value.The present invention utilizes simple circuit design, cheap hardware cost, just can reach good, compensation effect reliably.

More than explanation only is embodiments of the invention, be not to be used for limiting practical range of the present invention, those skilled in the art can not break away under the main idea of the present invention, carry out the distortion or the change of various execution modes, that is all equalization variations of doing according to claim of the present invention and modification, all should belong to covering scope of the present invention.

Claims (20)

1. current device comprises:

One bucking voltage produces circuit, is used for producing a bucking voltage, and this bucking voltage produces circuit and comprises:

One first electric crystal receives a reference current to produce this bucking voltage; And

One compensating unit, coupled in parallel is used for compensating this bucking voltage to this first electric crystal;

And

One current output unit comprises at least one second electric crystal, and this second electric crystal is used for according to this bucking voltage to export one first output current;

Wherein, this second electric crystal and this first electric crystal form a current-mirror structure.

2. current device as claimed in claim 1, this compensating unit wherein comprises:

One compensation electric crystal receives a reference voltage and connects structure in the lump with this first electric crystal formation.

3. current device as claimed in claim 1, wherein this current output unit also comprises:

One the 3rd electric crystal forms current-mirror structure with this first electric crystal, is used for according to this bucking voltage to export one second output current.

4. current device as claimed in claim 3 is applied to a charge pump circuit.

5. current device as claimed in claim 4, wherein this first output current is as the charging current of this charge pump circuit; And this second output current is as the discharging current of this charge pump circuit.

6. current device as claimed in claim 1, this current output unit wherein comprises:

One the 3rd electric crystal receives a control voltage, is used for exporting one second output current.

7. current device as claimed in claim 6, this compensating unit wherein comprises:

One compensation electric crystal receives a reference voltage and connects structure in the lump with this first electric crystal formation.

8. current device as claimed in claim 7 is applied to a voltage-controlled oscillator (VCO).

9. current device as claimed in claim 8, wherein this first output current and second output current are used for controlling the concussion frequency of the clock signal that this voltage-controlled oscillator (VCO) exports.

10. current device as claimed in claim 9, wherein when this control voltage equals this reference voltage in fact, the middle commotio cordis frequency of this clock signal is not subject to processing, the change of voltage and temperature influences.

11. current device as claimed in claim 1 is applied in the phase-locked loop.

12. a voltage-controlled oscillator (VCO) comprises:

One bucking voltage produces circuit, is used for producing a bucking voltage, and this bucking voltage produces circuit and comprises:

One first electric crystal receives a reference current to produce this bucking voltage; And

One compensating unit, coupled in parallel is used for compensating this bucking voltage to this first electric crystal;

One voltage-controlled current source is used for controlling voltage to produce a Control current according to this bucking voltage and; And

One delay cell is used for according to this Control current to postpone a clock signal and to export a delay clock signals.

13. voltage-controlled oscillator (VCO) as claimed in claim 12, this compensating unit wherein comprises:

One compensation electric crystal receives a reference voltage and connects structure in the lump with this first electric crystal formation.

14. voltage-controlled oscillator (VCO) as claimed in claim 12, this voltage-controlled current source wherein comprises:

One second electric crystal, this second electric crystal and this first electric crystal form and connect structure in the lump, are used for according to this bucking voltage to export an offset current; And

One control electric crystal is used for adjusting electric current according to this control voltage to export one;

Wherein, the electric current of this offset current and this adjustment electric current and equal this Control current in fact.

15. voltage-controlled oscillator (VCO) as claimed in claim 12, wherein when this control voltage equals this reference voltage in fact, the middle commotio cordis frequency of this clock signal is not subject to processing, the change of voltage and temperature influences.

16. voltage-controlled oscillator (VCO) as claimed in claim 12, wherein this delay cell is the delay cell of a differential mode.

17. voltage-controlled oscillator (VCO) as claimed in claim 12 is arranged among the phase-locked loop.

18. a charge pump comprises:

One bucking voltage produces circuit, is used for producing a bucking voltage, and this bucking voltage produces circuit, comprises:

One first electric crystal receives a reference current to produce this bucking voltage; And

One compensating unit, coupled in parallel is used for compensating this bucking voltage to this first electric crystal;

One current output unit forms current-mirror structure with this first electric crystal, is used for exporting a charging current and a discharging current according to this bucking voltage; And

One switch element is coupled to this current output unit, is used for controlling this charging current and this discharging current charging and discharging state to the electric charge delivery side of pump according to an input control signal.

19. charge pump as claimed in claim 18, this compensating unit wherein comprises:

One compensation electric crystal receives a reference voltage and connects structure in the lump with this first electric crystal formation.

20. charge pump as claimed in claim 18 is arranged among the phase-locked loop.

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