CN203135815U - Circuit of generating oscillation signal - Google Patents

Abstract

The utility model provides a circuit of generating an oscillation signal. The circuit of generating the oscillation signal comprises an oscillator module (10), and the module comprises a first MOS transistor (MN7) and a first capacitor (C1), wherein the first MOS transistor (MN7) comprises a grid, a source coupled with a reference voltage node and a drain coupled with a first trigger node of the oscillator module, and is used to generate an oscillation output signal of the oscillator module by being turned off and conducted alternatively; and the first capacitor (C1) is coupled between the grid and source of the first MOS transistor, and is configured to be charged or discharged alternatively corresponding to the oscillation signal to thereby conduct or turn off the first MOS transistor. The circuit also comprises a current source (20). The current source is configured to control a current flowing through the first MOS transistor, so that a voltage between the drain and the source of the first MOS transistor is not greater than a first value, when the first MOS transistor is conducted.

Description

Produce the circuit of oscillator signal

Technical field

The utility model relates to circuit, relates in particular to oscillating circuit.

Background technology

The oscillating circuit that has a few types at present.Fig. 1 to Fig. 4 shows wherein a kind of respectively.

But these oscillating circuits have their shortcoming, and especially to be arranged on these shortcomings of 20MHz additional hours especially remarkable when frequency of oscillation.The frequency limited of the RC oscillating circuit among Fig. 1 is in the speed of comparator.RC oscillating circuit among Fig. 2 can be subjected to the influence of the threshold variation of Schmidt trigger, and because RC is in the oscillation circuit, the adjustment of frequency (trimming) is difficulty relatively.Oscillating circuit among Fig. 3 is easy to adjust, but still can be subjected to the probabilistic influence of switching threshold.RC oscillating circuit among Fig. 4 is difficult to adjust, and the non-linear performance that also can influence it of electric capacity.

More importantly, because working condition, the difference of temperature, supply power voltage for example, and used semiconductor process variations when making transistor, transistor can't all have identical characteristic in all cases, that is to say that transistor can't stably work, therefore having transistorized oscillating circuit can not realize the stable higher-order of oscillation.

Therefore, need to realize a kind of stable oscillating circuit, no matter and the working condition that changes and the semiconductor technology of variation.Simultaneously, also need to realize a kind of oscillating circuit of adjusting frequency easily.

The utility model content

On the one hand, the utility model provides a kind of circuit, comprising:

-oscillator module (10), this module comprises:

-the first MOS transistor (MN7) has grid, is coupled to the source electrode of reference voltage node, and is coupled to the drain electrode that first of this oscillator module triggers node, is used for by alternately being turn-offed and conducting produces the oscillation output signal of this vibrator module;

-the first electric capacity (C1) is coupled between the grid and source electrode of first MOS transistor, and is configured to alternately be recharged corresponding to this oscillator signal or discharge, with this conducting of first MOS transistor or shutoff;

This circuit also comprises:

-current source (20) is configured to control the electric current of this first MOS transistor of flowing through, so that when this first MOS transistor is switched on, the drain electrode of this first MOS transistor and the voltage between the source electrode are not more than one first value.

In aspect this, current source is configured to provide suitable current to first MOS transistor, and this u allows the drain electrode of first MOS transistor and the voltage between the source electrode to be not more than first value.Therefore, no matter how operating state changes, first voltage that triggers node can be controlled, so this circuit can provide stable vibration output.

According to one preferred embodiment, this current source comprises:

Second MOS transistor (MN4) has the structure identical with first MOS transistor;

Voltage control module is configured to: when this second MOS transistor was switched on, drain electrode and the voltage between the source electrode of controlling second MOS transistor were not more than this first value;

Current mirror has a resistance, and this resistance is coupled between the grid and source electrode of second MOS transistor, and wherein, this current mirror is released the electric current identical with the electric current that flows through this resistance by first MOS transistor.

In this embodiment, because second MOS transistor has the structure identical with first MOS transistor, so these two transistorized working conditions also are identical with semiconductor technology.Therefore, by controlling second MOS transistor, and the electric current identical with the electric current that flows through second MOS transistor flow through first MOS transistor as bias current, this first MOS transistor also should be in the state identical with second MOS transistor, no matter and the variation of working condition and semi-conductor industry.

One preferred embodiment in, this current mirror electric current identical with the electric current that flows through this resistance this first electric capacity that charges of releasing.

In this embodiment, the frequency of oscillator module depends on the impedance of this resistance and the capacity of this first electric capacity.Therefore, by regulating the impedance of this resistance, this oscillator module can be balanced (trimmed) at an easy rate, and can not be subjected to the influence of parasitic parameter.

One preferred embodiment in, this voltage control module comprises:

The 3rd MOS transistor (MN3) has the source electrode of the drain electrode that is couple to second MOS transistor;

The 4th MOS transistor (MN1) has the source electrode of the grid that is couple to the 3rd MOS transistor;

The 5th MOS transistor (MN6) has the grid of the drain electrode of the grid that is couple to the 4th MOS transistor and the 3rd MOS transistor and the source electrode that is couple to the grid of this second MOS transistor; With

The 6th MOS transistor (MN2) has the drain and gate of the source electrode that all is couple to the 4th MOS transistor;

The 7th MOS transistor (MN5) has the drain electrode of the source electrode that is coupled to the 6th MOS transistor and is coupled to the source electrode of the source electrode of second MOS transistor;

Wherein, this second, third, the 4th, the 5th, the 6th have identical structure with the 7th MOS transistor, and,

Wherein, this current mirror is released identical electric current by the 3rd MOS transistor (MN3), the 4th MOS transistor (MN1) and the 5th MOS transistor.

This execution mode provides a concrete implementation of voltage control module.

One preferred embodiment in, this current source further comprises: first capacitive filter (CF1) is coupled between the source electrode of the grid of the 5th MOS transistor (MN6) and second MOS transistor (MN4).

In this embodiment, first capacitive filter can be avoided the problem of current oscillation.

One preferred embodiment in, this oscillator module also comprises:

The 8th MOS transistor (MN8), has grid, be coupled to the source electrode of reference voltage node, and the drain electrode that is couple to the second triggering node of this oscillator module, be used for by turn-on and turn-off alternately to generate the oscillation output signal of this oscillator module, the 8th MOS transistor have the structure identical with first MOS transistor and

Second electric capacity (C2) is coupled between the grid and source electrode of the 8th MOS transistor, and is configured in response to this oscillation output signal and by alternately charge or discharge, with the 8th MOS transistor conducting or shutoff;

Wherein, this oscillator module alternately charge this first and this second electric capacity, thereby alternately conducting this first and the 8th MOS transistor; And

Wherein, this current source is configured to control the electric current that flows through the 8th MOS transistor, makes that drain electrode and the voltage between the source electrode of the 8th MOS transistor is not more than first value when the 8th MOS transistor is switched on.

This execution mode uses astable multivibrator to realize this oscillator module.

Description of drawings

By reading the detailed description of doing with reference to the following drawings that non-limiting example is done, other features, objects and advantages of the present utility model will become more apparent:

Fig. 1 to Fig. 4 shows the oscillating circuit of traditional type respectively;

Fig. 5 shows the circuit 1 according to preferred implementation of the present utility model, comprises oscillation module 10 and current source 20;

Fig. 6 at length shows the current source 20 of the circuit 1 among Fig. 5;

Fig. 7 shows the switching characteristic of first MOS transistor of the oscillation module 10 of the circuit 1 among Fig. 5;

Fig. 8 shows the frequency change with respect to variations in temperature of the circuit 1 among Fig. 5;

Fig. 9 shows the Monte Carlo of the frequency change of the circuit 1 among Fig. 5 and analyzes.

Except as otherwise noted, in each accompanying drawing, corresponding numbering and the corresponding parts of symbol indication.Accompanying drawing is described clearly to use the related fields of execution mode of the present disclosure, and they might not be drawn in proportion.In order to clearly show that some execution mode, the letter that the variation pattern of same structure, material or process steps is shown may be placed on after the accompanying drawing number.

Embodiment

Manufacturing and the use of execution mode of the present utility model below will be described.Will be understood that the utility model provides the inventive concept that much has practicality, they can be implemented under the various specific scenes.Below the execution mode of describing only described make and use ad hoc fashion of the present utility model, and do not limit scope of the present utility model.

The utility model provides a kind of circuit, comprising:

-oscillator module, this module comprises:

-the first MOS transistor has grid, is coupled to the source electrode of reference voltage node, and is coupled to the drain electrode that first of this oscillator module triggers node, is used for by alternately being turn-offed and conducting produces the oscillation output signal of this vibrator module;

-the first electric capacity is coupled between the grid and source electrode of first MOS transistor, and is configured to alternately be recharged corresponding to this oscillator signal or discharge, with this conducting of first MOS transistor or shutoff;

This circuit also comprises:

-current source is configured to control the electric current of this first MOS transistor of flowing through, so that when this first MOS transistor is switched on, the drain electrode of this first MOS transistor and the voltage between the source electrode are not more than one first value.

The utility model also provides a kind of method, comprises the steps:

-by turn-on and turn-off first MOS transistor, will trigger to import being couple to reference voltage node via the drain electrode of this first MOS transistor (MN7) and source electrode;

The electric current of this first MOS transistor is flow through in-control, makes that drain electrode and the voltage between the source electrode in first MOS transistor is not more than first value when this first MOS transistor is switched on.

Fig. 5 shows the circuit 1 according to preferred implementation of the present utility model, comprises oscillation module 10 and current source 20.As shown in the figure, oscillation module 10 comprises the first MOS transistor MN7 and first capacitor C 1.The source electrode of the first MOS transistor MN7 is coupled to a reference voltage, for example bigly, and, by by first capacitor C 1 closed and disconnected alternately, produce the oscillation output signal of this oscillation module in its drain electrode.Preferably, oscillation module also comprises trigger, and the drain electrode of the first MOS transistor MN7 is coupled to first and triggers node T1, and this trigger is used for this oscillation output signal of shaping.First capacitor C 1 is coupled between the grid and source electrode of the first MOS transistor MN7, and is configured to corresponding to alternately being recharged by the oscillation output signal of shaping and discharging, with closed and disconnected first MOS transistor.In the embodiment shown in fig. 5, be used for according to being charged by the oscillation output signal of shaping and the circuit of first capacitor C 1 of discharging comprises switch MswN1 and switch MswP1.Switch MswN1 is in parallel with first capacitor C 1, and switch MswP1 is connected on first capacitor C 1 and is used between the current source 20 to 1 charging of first capacitor C.The closed and disconnected of two switch MswN1 of oscillation output signal control and MswP1: when oscillation output signal was low level, MswP1 closure and MswN1 disconnected, current source 20 chargings first capacitor C 1; And when oscillation output signal was high level, MswP1 disconnected and the MswN1 closure, and first capacitor C 1 is discharged.One of ordinary skill in the art is appreciated that for the circuit that charges according to oscillator signal with discharge capacity to have multiple implementation, and the utility model is not subjected to the restriction of above disclosed execution mode.

In the present embodiment, except the left side vibration side that comprises the above first MOS transistor MN7 and first capacitor C 1, this oscillation module 10 also comprises the right side vibration side of symmetry, and it comprises the 8th MOS transistor MN8 and second capacitor C 2.The source electrode of the 8th MOS transistor MN8 is coupled to reference voltage, for example bigly, and, by by second capacitor C 2 closed and disconnected alternately, produce the oscillation output signal of this oscillation module in its drain electrode.Preferably, oscillation module also comprises trigger, and the drain electrode of the 8th MOS transistor MN8 is coupled to second and triggers node T1, and this trigger is used for this oscillation output signal of shaping.Second capacitor C 1 is coupled between the grid and source electrode of the 8th MOS transistor MN8, and is configured to corresponding to alternately being recharged by the oscillation output signal of shaping and discharging, with closed and disconnected the 8th MOS transistor MN8.In the embodiment shown in fig. 5, be used for according to being charged by the oscillation output signal of shaping and the circuit of second capacitor C 2 of discharging comprises switch MswN2 and switch MswP2.Switch MswN2 is in parallel with second capacitor C 2, and switch MswP2 is connected on second capacitor C 2 and is used between the current source 20 to 2 chargings of second capacitor C.Oscillation output signal is controlled the closed and disconnected of two switch MswN2 and MswP2, thereby controls charging and the discharge of second capacitor C 2.

Oscillation module 10 among Fig. 5 contains left and right sides oscillating part, and it can be considered a kind of multivibrator.Will be understood that oscillation module 10 is not limited to this execution mode.In the execution mode of the variation of oscillation module 10, comprise that the right side vibration side of the 8th MOS transistor MN8 and second capacitor C 2 can be saved.One of ordinary skill in the art also can realize the oscillation module of other structures, and is all fallen into the scope of oscillation module by the various realizations that claim covered.In execution mode shown in Figure 5, the work of right vibration side and left side vibration side are similarly, therefore the hereinafter main work that vibration side in a left side is described in detail in detail.

When producing oscillator signal, the first MOS transistor MN7 should be closed and disconnect.When the first MOS transistor MN7 is closed, in order to make trigger, for example the rest-set flip-flop shown in Fig. 5 overturns to produce the oscillator signal of triggering, and first triggers the voltage at node T1 place, and just the voltage of the drain electrode of the first MOS transistor MN7 should be certain voltage near reference voltage.Therefore, when the first MOS transistor MN7 is closed, the drain electrode of the first MOS transistor MN7 and the voltage V between the source electrode _DSShould be not more than first value.Under different working conditions, for example temperature not simultaneously, the characteristic of first MOS transistor may change, therefore, V _DSThe electric current that flows through the first MOS transistor MN7 when being not more than this first value may be different.Therefore, in order to make V _DSGreater than first value, the electric current that flows through the first MOS transistor MN7 should be controlled in no instance.

Current source 20 is configured to control the electric current I that flows through the first MOS transistor MN7 _Bias, so that when the first MOS transistor MN7 is closed, the voltage V between drain electrode and the source electrode _DSBe not more than first value.

In one embodiment, inventive concept is to provide second MOS transistor with the first MOS transistor same structure, as " representative " of first MOS transistor.Because second MOS transistor and first MOS transistor have same structure, though the variation of the variation of working condition and semiconductor technology, always second MOS transistor is identical with first MOS transistor.Flow through the electric current of second MOS transistor by control, make the voltage between the drain electrode of second MOS transistor and the source electrode be not more than first value, the needs that same electric current should satisfy first MOS transistor make the voltage between the drain electrode of first MOS transistor and the source electrode be not more than first value.

Based on this inventive concept, current source 20 comprises:

The second MOS transistor MN4 has the structure identical with first MOS transistor;

Voltage control module is configured to: when this second MOS transistor was switched on, drain electrode and the voltage between the source electrode of controlling second MOS transistor were not more than this first value;

Current mirror has a resistance, and this resistance is coupled between the grid and source electrode of second MOS transistor, and wherein, this current mirror is released the electric current identical with the electric current that flows through this resistance by first MOS transistor.

For method, the control step comprises the steps:

The drain electrode of-control second MOS transistor the MN4 and the voltage between the source electrode make this voltage be not more than this first value, and this second MOS transistor has the structure identical with this first MOS transistor;

-between the grid of second MOS transistor and source electrode, couple a resistance R, and

-the electric current I identical with the electric current that flows through this resistance of releasing _BiasThrough this first MOS transistor.

Fig. 5 and Fig. 6 show the circuit structure of the current source 20 that has voltage control module and current mirror.This voltage control module comprises:

The 3rd MOS transistor MN3 has the source electrode of the drain electrode that is couple to second MOS transistor;

The 4th MOS transistor MN1 has the source electrode of the grid that is couple to the 3rd MOS transistor;

The 5th MOS transistor MN6 has the grid of the drain electrode of the grid that is couple to the 4th MOS transistor and the 3rd MOS transistor and the source electrode that is couple to the grid of this second MOS transistor; With

The 6th MOS transistor MN2 has the drain and gate of the source electrode that is couple to the 4th MOS transistor;

The 7th MOS transistor (MN5) has the drain electrode of the source electrode that is coupled to the 6th MOS transistor and is coupled to the source electrode of the source electrode of second MOS transistor,

Wherein, this second, third, the 4th, the 5th, the 6th have identical structure with the 7th MOS transistor,

Wherein, this current mirror is released identical electric current by the 3rd MOS transistor MN3, the 4th MOS transistor MN1 and the 5th MOS transistor MN6.This current mirror comprises a plurality of transistor MP1 to 7, these transistor drain are coupled to common voltage source, grid is coupled in once, and source electrode is couple to the 3rd MOS transistor MN3 respectively, the 4th MOS transistor MN1 and the 5th MOS transistor MN6, also be couple to the first MOS transistor MN7, first capacitor C 1 and the 8th MOS transistor MN8 and second capacitor C 2, and provide identical electric current to them.The general technology of this area is understood, and current mirror has other implementation, and these other implementation also all falls into protection range of the present utility model.

In the work of voltage control module, MOS transistor MN1 to 6 closure, and identical electric current flows through them.The drain electrode of the second MOS transistor MN4 and the Vds4 voltage between the source electrode are:

Vb1-Vgs1-Vgs3

Wherein, Vb1 is the voltage of the grid of MN1, and Vgs1 is the grid of MN1 and the voltage between the source electrode, and Vgs3 is the grid of MN3 and the voltage between the source electrode.

And, Vb1=VF+Vgs6, wherein VF is the voltage of the source electrode of MN6, also is the grid voltage with the second MOS transistor MN4 closure, Vgs6 is the grid of MN6 and the voltage between the source electrode.

Because it is identical to flow through the electric current of MN1 to 6, MN1 to 6 has identical Vgs, so Vds4 is close to zero.

Voltage control module among Fig. 5 and Fig. 6 is arranged to control the Vds of the second MOS transistor MN4 close to zero, therefore identical electric current flows through Vds that the first MOS transistor MN7 can make the MOS transistor MN7 that wins close to zero, thereby reference voltage is couple to trigger with this trigger that overturns.The circuit that is appreciated that the voltage control module among Fig. 5 and Fig. 6 only is example, and the circuit that one of ordinary skill in the art can design other is controlled the Vds of the second MOS transistor MN4.And, depending on the upset threshold voltage difference of trigger, the first required value may change.For example, when reference voltage was the earth zero volt, the turnover voltage of trigger was 0.1v, and first value can be 0.05v so; And the turnover voltage of trigger is 0.2v, and first value can be 0.1v so.Based on the first required value, voltage control module can be designed to correspondingly arrange the Vds of the second MOS transistor MN4, and the suitable Vds of the first MOS transistor MN7 is provided then.

The amplitude of this electric current is VF/r, and wherein r is the resistance of resistance R, the electric current of same magnitude first capacitor C 1 that also is used to charge.When the voltage of first capacitor C 1 reaches VF, the first MOS transistor closure.Therefore, the frequency of oscillation module 10 should be 1/ (VF*c/ (VF/r))=1/ (r*c), and wherein, c is the capacitance of first capacitor C 1.That is to say that the frequency of oscillation of this oscillation module 10 only depends on the capacitance of resistance and first capacitor C 1 of resistance R, therefore, by adjusting the resistance of resistance R, this oscillation module is easy to adjust frequency, and can not be subjected to the influence of parasitic parameter.

Preferably, first capacitive filter CF1 is coupled between the source electrode of the grid of the 5th MOS transistor MN6 and the second MOS transistor MN4.This first capacitive filter CF1 can avoid the current oscillation problem.And preferably, second capacitive filter CF2 is arranged in parallel with left side vibration side and right vibration side, realizes better switch stability with the filtering common node.

The electric current I that is used for oscillation module 10 _BiasCan be calculated as follows:

$\left\{\begin{array}{c}{I}_{\mathrm{bias}}=0.5u{C}_{\mathrm{ox}}\frac{W}{L}{(V_{\mathrm{gs}2}-V_{\mathrm{th}})}^2\\ I_{\mathrm{bias}}=0.5u{C}_{\mathrm{ox}}\frac{W}{L}(I_{\mathrm{bias}}*R-V_{\mathrm{th}})V_{\mathrm{ds}4}\\ I_{\mathrm{bias}}=0.5u{C}_{\mathrm{ox}}\frac{W}{L}{(V_{\mathrm{gs}2}-V_{\mathrm{th}}-V_{\mathrm{ds}4})}^2\end{array}\right.$

$\→I_{\mathrm{bias}}=[0,\frac{V_{\mathrm{th}}}{R}+\frac{0.25L}{\mathrm{Ru}{C}_{\mathrm{ox}}W}(1+\sqrt{1+\frac{8\mathrm{Ru}{C}_{\mathrm{ox}}{V}_{\mathrm{thW}}}{L}}),\frac{V_{\mathrm{th}}}{R}-\frac{0.25L}{\mathrm{Ru}{C}_{\mathrm{ox}}W}(-1+$

$\sqrt{1+\frac{8\mathrm{Ru}{C}_{\mathrm{ox}}{V}_{\mathrm{th}}W}{L}}\left)\right]$

$\→\mathrm{Ibias}=\frac{V_{\mathrm{th}}}{R}+\frac{0.25L}{\mathrm{Ru}{C}_{\mathrm{ox}}W}(1+\sqrt{1+\frac{8\mathrm{Ru}{C}_{\mathrm{ox}}{V}_{\mathrm{th}}W}{L}})$

In order to obtain the performance of desirable oscillation module, the switching threshold voltage of trigger is adjusted to high relatively level helps to increase oscillatory stability.In execution mode shown in Figure 5, provide rest-set flip-flop 1 and the rest-set flip-flop 2 of cascade.One of ordinary skill in the art is appreciated that the trigger of other interfaces also can replace.

Fig. 7 to 9 shows the simulation result of the circuit among Fig. 5.The condition of emulation is the CMOS technology of 0.18 μ.

Fig. 7 shows the switching characteristic of first MOS transistor of the oscillation module 10 of the circuit 1 among Fig. 5.In Fig. 7, horizontal line represents the grid voltage of the second MOS transistor MN4, i.e. VF.Curve represents the grid voltage of the first MOS transistor MN7, has also reflected the charging of first capacitor C 1 and closure and the disconnection of discharge and the first MOS transistor MN7.

Fig. 8 shows the frequency change with respect to variations in temperature of the circuit 1 among Fig. 5.As can be seen, in-40 degrees centigrade to 120 degrees centigrade very wide temperature range, frequency of oscillation is in ± 1% excursion in.As seen, the circuit that proposes is the holding frequency temperature in very wide temperature range.

Fig. 9 shows the Monte Carlo of the frequency change of the circuit 1 among Fig. 5 and analyzes.

Need to prove that under the situation of not conflicting, the embodiment among the application and the feature among the embodiment be combination in any mutually.

Certainly; the utility model also can have other various embodiments; under the situation that does not deviate from the utility model spirit and essence thereof; those of ordinary skill in the art can make various corresponding changes and distortion according to the utility model, but these corresponding changes and distortion all should belong to the protection range of the appended claim of the utility model.

One of ordinary skill in the art will appreciate that all or part of step in the said method can instruct related hardware to finish by program, described program can be stored in the computer-readable recording medium, as read-only memory, disk or CD etc.Alternatively, all or part of step of above-described embodiment also can use one or more integrated circuits to realize.Correspondingly, each the module/unit in above-described embodiment can adopt the form of hardware to realize, also can adopt the form of software function module to realize.The utility model is not restricted to the combination of the hardware and software of any particular form.

Claims (7)

1. a circuit is characterized in that, comprising:

-oscillator module (10), this module comprises:

-the first MOS transistor (MN7) has grid, is coupled to the source electrode of reference voltage node, and is coupled to the drain electrode that first of this oscillator module triggers node, is used for by alternately being turn-offed and conducting produces the oscillation output signal of this vibrator module;

-the first electric capacity (C1) is coupled between the grid and source electrode of first MOS transistor, and is configured to alternately be recharged corresponding to this oscillator signal or discharge, with this conducting of first MOS transistor or shutoff;

This circuit also comprises:

-current source (20) is configured to control the electric current of this first MOS transistor of flowing through, so that when this first MOS transistor is switched on, the drain electrode of this first MOS transistor and the voltage between the source electrode are not more than one first value.

2. circuit according to claim 1, wherein, this current source comprises:

Second MOS transistor (MN4) has the structure identical with first MOS transistor;

Voltage control module is configured to: when this second MOS transistor was switched on, drain electrode and the voltage between the source electrode of controlling second MOS transistor were not more than this first value;

Current mirror has a resistance, and this resistance is coupled between the grid and source electrode of second MOS transistor, and wherein, this current mirror is released the electric current identical with the electric current that flows through this resistance by first MOS transistor.

3. circuit according to claim 2, wherein, this voltage control module comprises:

The 3rd MOS transistor (MN3) has the source electrode of the drain electrode that is couple to second MOS transistor;

The 4th MOS transistor (MN1) has the source electrode of the grid that is couple to the 3rd MOS transistor;

The 5th MOS transistor (MN6) has the grid of the drain electrode of the grid that is couple to the 4th MOS transistor and the 3rd MOS transistor and the source electrode that is couple to the grid of this second MOS transistor; With

The 6th MOS transistor (MN2) has the drain and gate of the source electrode that all is couple to the 4th MOS transistor;

Wherein, this second, third, the 4th, the 5th have identical structure with the 6th MOS transistor, and,

Wherein, this current mirror is released identical electric current by the 3rd MOS transistor (MN3), the 4th MOS transistor (MN1) and the 5th MOS transistor.

4. circuit according to claim 3, wherein, this voltage control control further comprises:

The 7th MOS transistor (MN5) has the drain electrode of the source electrode that is coupled to the 6th MOS transistor and is coupled to the source electrode of the source electrode of second MOS transistor,

Wherein, the 7th MOS transistor has the structure identical with second MOS transistor.

5. circuit according to claim 3, wherein, this current source further comprises:

First capacitive filter (CF1) is coupled between the source electrode of the grid of the 5th MOS transistor (MN6) and second MOS transistor (MN4).

6. circuit according to claim 1, wherein, this oscillator module also comprises:

The 8th MOS transistor (MN8), has grid, be coupled to the source electrode of reference voltage node, and the drain electrode that is couple to the second triggering node of this oscillator module, be used for by turn-on and turn-off alternately to generate the oscillation output signal of this oscillator module, the 8th MOS transistor have the structure identical with first MOS transistor and

Second electric capacity (C2) is coupled between the grid and source electrode of the 8th MOS transistor, and is configured in response to this oscillation output signal and by alternately charge or discharge, with the 8th MOS transistor conducting or shutoff;

Wherein, this oscillator module alternately charge this first and this second electric capacity, thereby alternately conducting this first and the 8th MOS transistor; And

Wherein, this current source is configured to control the electric current that flows through the 8th MOS transistor, makes that drain electrode and the voltage between the source electrode of the 8th MOS transistor is not more than first value when the 8th MOS transistor is switched on.

7. circuit according to claim 2, wherein, this current mirror electric current identical with the electric current that flows through this resistance this first electric capacity that charges of releasing.

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