Auto-bias voltage stabilizing circuit
Technical field
The present invention is about a kind of mu balanced circuit, particularly about a kind of auto-bias voltage stabilizing circuit of automatic corrects bias voltage.
Background technology
Voltage stabilizer is that a kind of output voltage of adjusting automatically is to be used to produce the feed circuit or the power-supply unit of stable output voltage, its effect is that fluctuation the supply voltage big and requirement of inadequacy electric equipment is stabilized in its range of set value, make various circuit or the electric equipment can be in operate as normal under the rated operational voltage, it can be widely used in industrial and mining enterprises, the oil field, railway, the building ground, school, hospital, post and telecommunications, the hotel, the robot calculator of departments such as scientific research, precision machine tool, computed tomography photography (CT), exact instrument, test unit, elevator lighting, import equipment and production line etc. need the place of power supply burning voltage, also being adapted to supply voltage crosses low or too high, the user of the low-voltage network end that fluctuating range is big and the big consumer of load change are specially adapted to all to the demanding voltage stabilizing electricity consumption of electrical network waveform place.
Fig. 1 is the typical circuit figure of mu balanced circuit in the prior art, and in the prior art, mu balanced circuit comprises level displacement shifter 101, operational amplifier 102 and feedback network 103.Level displacement shifter 101 compares and exports two difference voltage V+, V-to operational amplifier 102 with the feedback voltage V IN of reference voltage V REF and feedback network feedback, operational amplifier 102 amplifies difference voltage V+, V-and produce required burning voltage is output voltage VO UT, and the output voltage VO UT of 103 pairs of operational amplifiers of feedback network, 102 outputs takes a sample and feeds back feedback voltage V IN and carry out dynamic monitoring to level displacement shifter 101.
Certainly, in above-mentioned mu balanced circuit, level displacement shifter 101 and the extra bias voltage BIAS of operational amplifier 102 needs could be in best region work.Yet, in the prior art, generally provide this extra bias voltage with fixed voltage, because integrated circuit process parameter is always pressed certain statistical distribution but not is completely specified, so fixed bias voltage can not be taken into account all situations of changes in process parameters, adopt fixed bias voltage can make those level displacement shifter exclusive disjunction amplifiers that are in edge parameters can not work in optimum condition, thereby influence the performance parameter of mu balanced circuit.
In sum, there are the following problems for the mu balanced circuit of prior art as can be known, the extensive distribution range that can't take into account technological parameter owing to working in fixed bias voltage can make level displacement shifter exclusive disjunction amplifier can not work in the performance parameter that optimum condition influences mu balanced circuit, therefore be necessary to propose improved technological means in fact, solve this problem.
Summary of the invention
For overcoming the various shortcoming of above-mentioned prior art, fundamental purpose of the present invention is to provide a kind of auto-bias voltage stabilizing circuit, it mainly is bias voltage to be provided and it is carried out from normal moveout correction by a bias voltage automatic calibration circuit, with the stable bias voltage of automatic generation, thereby reach the purpose that need not use fixing bias voltage, improved the performance of mu balanced circuit.
For reaching above-mentioned and other purpose, a kind of auto-bias voltage stabilizing circuit of the present invention comprises at least:
First level displacement shifter has first input end, second input end and one first bias voltage control end at least, and this first input end connects a reference voltage; This second input end is connected in feedback circuit to obtain feedback voltage, and this first level displacement shifter compares and export first group of two difference voltage to this reference voltage and this feedback voltage;
First operational amplifier is connected in this first level displacement shifter to obtain this first group of two difference voltage, this first group of two difference voltage is amplified and is produced an output voltage export, and this first operational amplifier has one second bias voltage control end at least;
Feedback circuit is connected in this first operational amplifier and this first level displacement shifter, this output voltage is taken a sample and feed back this feedback voltage to this first level displacement shifter; And
The bias voltage automatic calibration circuit, at least have the 3rd input end and four-input terminal, the 3rd input end and four-input terminal all are connected to reference voltage, the output terminal of this bias voltage automatic calibration circuit is connected to this first bias voltage control end and this second bias voltage control end, this bias voltage automatic calibration circuit is converted to differential voltage in order to the variation with the technological parameter of this first level displacement shifter and exports this first bias voltage control end and this second bias voltage control end to, thinks that this first level displacement shifter and this first operational amplifier provide bias voltage.
Further, this bias voltage automatic calibration circuit also comprises:
Second level displacement shifter, this second level displacement shifter receive the reference voltage of the 3rd input end and this four-input terminal and export second group of two difference voltage; And
Second operational amplifier amplifies and produces this bias voltage this second group of two difference voltage and exports this first bias voltage control end and this second bias voltage control end to.
Further, this output voltage also is connected to this second level displacement shifter and this second operational amplifier, thinks that this second level displacement shifter and this second operational amplifier provide bias voltage.
Further, this first level displacement shifter is identical with the technological parameter of this second level displacement shifter
Compared with prior art, a kind of auto-bias voltage stabilizing circuit of the present invention provides bias voltage for main mu balanced circuit by increasing by a bias voltage automatic calibration circuit identical with main mu balanced circuit structure, and provide to this bias voltage from normal moveout correction, so that stable bias voltage is provided, make main mu balanced circuit of the present invention need not use fixing bias voltage and can obtain stable bias voltage, thereby reach bias voltage and do not influence technological parameter, improve the purpose of mu balanced circuit performance.
Description of drawings
Fig. 1 is the circuit diagram of a kind of mu balanced circuit of prior art;
Fig. 2 is the circuit structure diagram of a kind of auto-bias voltage stabilizing circuit of the present invention;
Fig. 3 is the circuit diagram of a kind of auto-bias voltage stabilizing circuit one preferred embodiment of the present invention.
Embodiment
Below by specific instantiation and accompanying drawings embodiments of the present invention, those skilled in the art can understand other advantage of the present invention and effect easily by the content that this instructions disclosed.The present invention also can be implemented or be used by other different instantiation, and the every details in this instructions also can be based on different viewpoints and application, carries out various modifications and change under the spirit of the present invention not deviating from.
Fig. 2 is the circuit diagram of a kind of auto-bias voltage stabilizing circuit of the present invention.As shown in Figure 2, a kind of auto-bias voltage stabilizing circuit 20 of the present invention comprises main mu balanced circuit 21 and bias voltage automatic calibration circuit 22, and wherein main mu balanced circuit 21 comprises level displacement shifter 210, operational amplifier 211 and feedback circuit 212.
Supply voltage VDD is the input voltage of main mu balanced circuit 21, and it provides supply voltage for main mu balanced circuit 21 each parts, and output voltage VO UT is the output voltage of main mu balanced circuit 21.Level displacement shifter 210 has the first input end and second input end, its first input end is connected with reference voltage V REF, its second input end is connected with feedback circuit 212, and this level displacement shifter 210 compares and export first group of two difference voltage V with this reference voltage V REF and feedback voltage V IN
1+ and V
1-, for making this level displacement shifter 210 energy operate as normal, this level displacement shifter 210 also has one first bias voltage control end, and this first bias voltage control end is connected with bias voltage automatic calibration circuit 22, provides bias voltage by this bias voltage automatic calibration circuit 22 to it; Above-mentioned first group of two difference voltage V
1+ and V
1-be admitted to after operational amplifier 211 amplifies, export stable output voltage VO UT, this operational amplifier 211 also has one second bias voltage control end, this second bias voltage control end is connected with this bias voltage automatic calibration circuit 22, provides bias voltage by this bias voltage automatic calibration circuit 22 to it; Then, this output voltage VO UT is admitted to feedback circuit 212 and takes a sample, and feeds back a feedback voltage V IN to this level displacement shifter 210 by this feedback circuit 212.
Bias voltage automatic calibration circuit 22 has two input ends, these two input ends all are connected with reference voltage V REF, the output terminal of this bias voltage automatic calibration circuit 22 is connected to the first bias voltage control end and the second bias voltage control end of main mu balanced circuit 21, provide first bias voltage and second bias voltage with level displacement shifter 210 and the operational amplifier 211 that is respectively this main mu balanced circuit 21, this bias voltage automatic calibration circuit 22 also has a bias input end, this bias input end is connected with the output terminal of this bias voltage automatic calibration circuit 22, this bias voltage automatic calibration circuit 22 is used for the variation of technological parameter is converted to differential voltage output, and finally be presented as to this first bias voltage and this second bias voltage from normal moveout correction, among the present invention, main mu balanced circuit 21 is identical with the technological parameter of bias voltage automatic calibration circuit 22, its changes in process parameters also was identical when the historical facts or anecdotes border produced, and the output of bias voltage automatic calibration circuit 22 does not extremely influence circuit performance with the technological parameter offset correction of main mu balanced circuit yet in the correction process parameter error.
The present invention see also Fig. 3 in order more clearly to illustrate, it is depicted as the circuit diagram of the auto-bias voltage stabilizing circuit that a preferred embodiment of the present invention provides.This auto-bias voltage stabilizing circuit 30 comprises main mu balanced circuit 31 and bias voltage automatic calibration circuit 32, wherein main mu balanced circuit 31 comprises first level displacement shifter 310, first operational amplifier 311 and feedback circuit 312, and bias voltage automatic calibration circuit 32 comprises second level displacement shifter 320 and second operational amplifier 321.
For main mu balanced circuit 31 parts, identical with above-mentioned part, the first input end of first level displacement shifter 310 is connected with reference voltage V REF, second input end is connected with feedback circuit 312, and this first level displacement shifter 310 compares and export first group of two difference voltage V with this reference voltage V REF and feedback voltage V IN
1+ and V
1-; Above-mentioned first group of two difference voltage V
1+ and V
1-be admitted to after first operational amplifier 311 amplifies, export stable output voltage VO UT, then, this output voltage VO UT is admitted to feedback circuit 312 and takes a sample, and feeds back a feedback voltage V IN to this first level displacement shifter 310.
For these bias voltage automatic calibration circuit 32 parts, supply voltage VDD is connected with the each several part of this bias voltage automatic calibration circuit 32, with supply voltage, for the each several part of this bias voltage automatic calibration circuit 32 provides supply voltage as this bias voltage automatic calibration circuit 32.Second level displacement shifter 320 comprises the 3rd input end and four-input terminal, and the 3rd input end and four-input terminal all are connected to reference voltage V REF, second group of two difference voltage V of these second level displacement shifter, 320 outputs
2+ and V
2-to this second operational amplifier 321, by this operational amplifier 321 with this second group of two difference voltage V
2+ and V
2-amplify and produce stable output voltage V BIAS, this output voltage V BIAS is connected to first bias voltage control end of this first level displacement shifter 310 and the second bias voltage control end of this first operational amplifier 311, be respectively this first level displacement shifter 310 and provide bias voltage with this first operational amplifier 311, simultaneously, this output voltage V BIAS also is connected to this second level displacement shifter 320 and this second operational amplifier 321, is respectively this second level displacement shifter 320 and this second operational amplifier 321 provides bias voltage.
Be without loss of generality, suppose that technological reason makes the output difference of second level displacement shifter 320 increase, then concerning second level displacement shifter 320, this difference is amplified back output through second operational amplifier 321, make the voltage VBIAS of second operational amplifier, 321 outputs raise, because of this output be fed simultaneously to second level displacement shifter 320 as its bias voltage, design is inversely proportional to the output of this second level displacement shifter 320 and its bias voltage, then the output difference of second level displacement shifter 320 can tend to reduce, make second level displacement shifter 320 be output as certain fixedly difference after adjusting repeatedly, this fixedly difference be output as new bias voltage VBIAS after being amplified by second operational amplifier 321, changes in process parameters is biased voltage automatic calibration circuit 22 and is converted into new bias voltage VBIAS like this; Because the circuit of first level displacement shifter 310 and second level displacement shifter 320 and biasing are identical, then the output increment that causes because of changes in process parameters of second level displacement shifter 320 is biased voltage VBIAS and dynamically adjusts most certain fixedly difference the time, the output increment that first level displacement shifter 310 causes because of changes in process parameters also is biased voltage VBIAS and dynamically is adjusted to the same fixed difference, that is under the correction of this bias voltage automatic calibration circuit 32, first level displacement shifter 310 is eliminated automatically because of the output that technological parameter causes, thereby the output of main voltage stabilizer does not change because of the variation of technological parameter.
The foregoing description is illustrative principle of the present invention and effect thereof only, but not is used to limit the present invention.Any those skilled in the art all can be under spirit of the present invention and category, and the foregoing description is modified and changed.Therefore, the scope of the present invention should be listed as claims.