CN100587646C - Voltage supply circuit, power supply circuit, microphone unit, and sensitivity adjustment method - Google Patents
Voltage supply circuit, power supply circuit, microphone unit, and sensitivity adjustment method Download PDFInfo
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- CN100587646C CN100587646C CN200610005754A CN200610005754A CN100587646C CN 100587646 C CN100587646 C CN 100587646C CN 200610005754 A CN200610005754 A CN 200610005754A CN 200610005754 A CN200610005754 A CN 200610005754A CN 100587646 C CN100587646 C CN 100587646C
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Abstract
A voltage supply circuit includes a power supply booster, an amplifier operating with a voltage generated by the power supply booster as a power supply voltage and supplying a bias voltage to a sensor, and an output voltage setting part including a feedback resistor for the amplifier. The feedback resistor has resistance determined according to a set value of a bias voltage of the sensor.
Description
Technical field
The present invention relates to a kind of voltage supply circuit, exactly, relate to a kind of be used for to such as the voltage supply circuit of sensors such as capacitor loudspeaker supplies voltage, use the microphone unit of this circuit, and regulate the microphone unit sensitivity of method.
Background technology
In such as portable terminals such as cell phones, extensively adopted and used the micropkonic technology that is called as capacitor loudspeaker to be used for voice communication.Capacitor loudspeaker is a kind of like this capacitor, and it is that the capacitor of vibrating membrane forms by one electrode, and can come the vibration of perceives sound etc. and convert it into electric signal by changes in capacitance.
The capacitor loudspeaker system of a standard has been told about in " PA audio communication system " (Kougakutosho company limited, 1996).Figure 20 shows the circuit of the capacitor loudspeaker unit 100 that uses capacitor loudspeaker.As shown in figure 20, existing capacitor loudspeaker unit comprises capacitor loudspeaker 101, technotron (JFET) 102, capacitor 103, resistor 104 and 105, and DC power supply 106 and 108.
Capacitor loudspeaker 101 is for being used to receive such as acoustic pressure such as sound and generating the vibration transducer of output signal.An electrode of capacitor loudspeaker 101 is connected to DC power supply 108 by resistor 104, and another electrode grounding.Capacitor loudspeaker 101 receives certain bias voltage from DC power supply 108.The output terminal of capacitor loudspeaker 101 is connected to the grid of JFET 102.JFET102 is used to amplify from the output signal of capacitor loudspeaker 101 and the amplifier of generation amplifying signal.The amplifying signal that generates in JFET 102 is by output terminal 107 100 outputs from the capacitor loudspeaker unit.
Though capacitor loudspeaker unit 100 as shown in figure 20 uses two DC power supplys 106 and 108, it also is feasible promoting the bias voltage that the voltage supplied from DC power supply 106 waits to be fed to capacitor loudspeaker 101 with generation.
In this capacitor loudspeaker unit, in the process of making capacitor loudspeaker and JFET manufacture deviation may take place.This manufacture deviation can cause the deviation of the amplification efficient of range deviation between the electrode for capacitors and JFET, and this can cause the capacitor loudspeaker unit to have different sensitivity.
Therefore, even need to take place manufacture deviation in such as senser elements such as capacitor loudspeakers always, the capacitor loudspeaker unit also can be with appropriate sensitivity operation.
And then prior art is provided with the sensitivity that two different capacitor loudspeaker unit and own switch-capacitor microphone unit change the capacitor loudspeaker unit by preparing sensitivity.In this structure, be necessary to prepare the same number of capacitor loudspeaker unit of number and to be switched sensitivity level.Therefore, the capacitor loudspeaker unit that needs permission in a unit, between a plurality of sensitivity levels, to select.
Summary of the invention
According to an aspect of the present invention, the voltage supply circuit of proposition comprises the power supply stepup transformer; Amplifier moves as supply voltage with the voltage that generates by the power supply stepup transformer, and bias voltage is supplied to sensor; And output voltage is provided with part, comprises the feedback resistor that is used for amplifier, and this feedback resistor has the resistance of determining according to bias voltage value of setting of sensor.
This structure can select to be used to be supplied to the bias voltage such as sensors such as capacitor loudspeakers.
According to another aspect of the present invention, the microphone unit of proposition comprises loudspeaker, is used to receive bias voltage; The power supply stepup transformer; And amplifier, move as supply voltage with the voltage that generates by the power supply stepup transformer, and bias voltage is supplied to loudspeaker; And output voltage is provided with part, comprises the feedback resistor that is used for amplifier, and this feedback resistor has the resistance of determining according to micropkonic bias voltage value of setting.
This structure can reduce the sensitivity variations of microphone unit.
According to a further aspect of the invention, proposition be used to regulate the loudspeaker sensitivity of method and comprise reference tone reftone is input to loudspeaker; Micropkonic output and the reference voltage that is used for reference tone reftone compared; Export the value of setting according to comparative result, be used to be provided with the micropkonic bias voltage of deflection; And storage value of setting and be identified for the feedback resistance value of the amplifier of output offset voltage according to the value of setting.
This sensitivity adjusting operation can reduce the sensitivity variations of microphone unit.
Description of drawings
Tell about below in conjunction with accompanying drawing carried out will make of the present invention above-mentioned and other targets, advantage and feature are more clear, wherein:
Fig. 1 shows capacitor loudspeaker of the present invention unit;
Fig. 2 shows the voltage supply circuit according to the capacitor loudspeaker unit of first embodiment of the invention;
Fig. 3 shows sensitivity adjusting equipment of the present invention;
Fig. 4 shows the sensitivity of capacitor loudspeaker unit and the relation between the bias voltage;
Fig. 5 shows from value of setting of conditioning signal maker output and the amount of regulating bias voltage;
Fig. 6 shows the shift register in the data processor;
Fig. 7 is a circuit diagram, show from the structure of the switch of the corresponding storer of first selector to the first selector;
Fig. 8 shows the capacitor loudspeaker unit according to second embodiment of the invention;
Fig. 9 shows the capacitor loudspeaker unit according to third embodiment of the invention;
Figure 10 shows the capacitor loudspeaker unit according to fourth embodiment of the invention;
Figure 11 shows the situation of another circuit as storer of using;
Figure 12 shows the situation of another circuit as storer of using;
Figure 13 shows the situation of another circuit as storer of using;
Figure 14 shows the capacitor loudspeaker unit according to fifth embodiment of the invention;
Figure 15 shows the operation according to the capacitor loudspeaker unit of fifth embodiment of the invention;
Figure 16 shows the capacitor loudspeaker unit according to sixth embodiment of the invention;
Figure 17 shows the operation according to the capacitor loudspeaker unit of sixth embodiment of the invention;
Figure 18 shows the operation according to the capacitor loudspeaker unit of seventh embodiment of the invention;
Figure 19 shows the capacitor loudspeaker unit according to eighth embodiment of the invention;
Figure 20 shows existing capacitor loudspeaker unit.
Embodiment
Tell about the present invention referring now to explanatory embodiment.One of ordinary skill in the art is all known, use of the present invention telling about can finish many optional embodiments, and the present invention is not limited to be used for the embodiment of explanatory purpose.
Following examples are told about as the example of microphone unit with the capacitor loudspeaker unit.
First embodiment
Fig. 1 shows the capacitor loudspeaker unit according to first embodiment of the invention.The capacitor loudspeaker unit of first embodiment comprises voltage supply circuit 1, capacitor loudspeaker 2, amplifier 3, capacitor 4, resistor 5 and 6, and power supply 7.
In this capacitor loudspeaker unit, vibrate as the vibrating membrane response sound of the capacitor loudspeaker 2 of vibration transducer etc.Because electric capacity changes when vibrating membrane vibrates, so be stored in also respective change of electric charge in the capacitor loudspeaker 2.Based on the change of electric charge, the node voltage between resistor 5 and the capacitor loudspeaker 2 also changes.Change in voltage is supplied to the gate electrode of JFET 3 by capacitor 4 as the output signal of capacitor loudspeaker 2.3 pairs of output signals from capacitor loudspeaker 2 of JFET are amplified, and with its source electrode and output of the node between the resistor 6 from JFET 3, as the output signal of capacitor loudspeaker unit.
Capacitor 4 cuts off the DC component of the voltage of the grid of waiting to be supplied to JFET 3.The grid of 5 pairs of impedances of resistor and JFET 3 mates.
The capacitor loudspeaker unit of first embodiment has high sensitivity pattern and low sensitivity mode.In the high sensitivity pattern, first bias voltage (for example being about 24V) is applied to capacitor loudspeaker 2; In low sensitivity mode, it is applied second bias voltage (for example being about 12V).During the operation of capacitor microphone unit, the mode designating signal that will be used to the pattern that is provided with is fed to voltage supply circuit 1 from the outside.Voltage supply circuit 1 is applied to capacitor loudspeaker according to mode designating signal with first or second bias voltage.
In continued operation, the basic voltage that is fed to capacitor loudspeaker 2 from voltage supply circuit 1 is determined by mode designating signal.But, as previously mentioned, in the capacitor loudspeaker unit manufacture deviation has taken place.Therefore, the voltage supply circuit 1 of first embodiment is configured to regulate first and second bias voltages by the sensitivity adjusting of carrying out in advance, as described later.Tell about voltage supply circuit 1 now in detail.
Fig. 2 is a block diagram, shows the structure of the voltage supply circuit 1 of first embodiment.The voltage supply circuit 1 of first embodiment comprises that power supply stepup transformer 21, voltage stabilizer 22 and output voltage are provided with part 23.
Power supply stepup transformer 21 will rise to essential voltage levvl (for example about 24V) and the voltage of output through promoting from the voltage (for example 5V) of power supply 7 supplies.Power supply stepup transformer 21 can be carried out by for example charge pump or DC/DC converter.
The voltage that 221 pairs of non-inverting amplifiers are fed to its non-inverting input amplifies and it is exported as bias voltage.The amplification degree is that the resistance value by feedback resistor decides.Say exactly, be by the resistance value of feedback resistor and be connected the non-inverting input of non-inverting amplifier 221 and the ratio of the resistance value of the resistor between the ground decides.Therefore, be to be provided with from the bias voltage of voltage supply circuit 1 output by the feedback resistance value that output voltage is provided with part 23.
Output voltage is provided with part 23 bias voltage for the treatment of from voltage stabilizer 22 outputs is set.Output voltage is provided with part 23 and by the feedback resistance value that changes amplifier 221 bias voltage is set.Output voltage is provided with part 23 and has first feedback resistor 231 and second feedback resistor 232.During the high sensitivity pattern, use first feedback resistor 231, and during low sensitivity mode, use second feedback resistor 232.Output voltage is provided with part 23 according to mode designating signal, optionally uses first or second feedback resistor, thereby switches between high sensitivity pattern and low sensitivity mode.
In the voltage supply circuit 1 of first embodiment, BGR 222 generates reference voltage according to the voltage from power supply 7 supplies.Reference voltage amplifies by non-inverting amplifier 221 and is outputted as bias voltage.At this moment, output voltage is provided with part 23 receiving mode specification signals, and selects first feedback resistor 231 or second feedback resistor 232.The required power of non-inverting amplifier 221 outputs amplification voltage generates by power supply stepup transformer 21.Use the voltage supply circuit 1 of this structure to allow generation to be used for the bias voltage of high sensitivity pattern and the bias voltage of low sensitivity mode, and the capacitor loudspeaker unit move with these voltages.
The output voltage that comes to tell about in detail to be used to regulate bias voltage below is provided with the structure of part 23.The output voltage of first embodiment is provided with part 23 and comprises first and second feedback resistors 231 and 232, first and second selector switchs 233 and 234, data processor 235 and storer 236.Feedback resistor 231 and 232 is included in a plurality of resistors of connecting between the output terminal of non-inverting amplifier 221 and the ground.In first embodiment, feedback resistor 231 and 232 each have 8 resistors of series connection.Feedback resistor 231 and 232 is parallel-connected to non-inverting amplifier 221.
Output voltage is provided with part 23 to have according to described sensitivity adjusting after a while and operates the storer 236 of storing the value of setting.Data processor 235 output is stored in the value of setting in the storer 236 and exports the signal of the switch that is used for selecting selector switch 233 and 234.The value of setting that is stored in the storer 236 is corresponding with the value of setting that is used to be provided with feedback resistance value, to regulate bias voltage.Data processor 235 is gone back the receiving mode specification signal, and output is used for selectively first feedback resistor 231 or second feedback resistor 232 are connected to the switch controlling signal of amplifier 221.
Therefore, the circuit of data processor 235 for being used to export the pattern of being used to specify and regulating the value of setting of bias voltage.
The voltage supply circuit 1 of first embodiment is regulated first bias voltage value and second bias voltage value in sensitivity adjusting, and this value of setting that is provided as feedback resistor is stored in the storer 236.
In the routine operation when actual use capacitor loudspeaker unit the time, voltage supply circuit 1 receives only mode designating signal.At this moment, the output voltage in voltage supply circuit 1 is provided with in the part 23, the value of setting that data processor 235 outputs are stored, and the signal that is used to select first or second feedback resistor.In selector switch 233 and 234, select and the corresponding switch of Value Data is set, and the individual resistor of arbitrary number (1～7) in 8 resistors in the feedback resistor is connected to non-inverting amplifier 221.Feedback resistance value is by this operation setting.The amplification degree of non-inverting amplifier 221 is by first or second feedback resistor that links to each other and is connected to the number decision of the resistor of the inverting input in each feedback resistor.Thereby output offset voltage.
In this structure, the capacitor loudspeaker unit of first embodiment moves with high sensitivity pattern or low sensitivity mode.The sensitivity variations of capacitor loudspeaker unit can be proofreaied and correct by being applied to the bias voltage that has passed through adjusting in the voltage supply circuit 1 according to sensitivity adjusting.This allows the capacitor loudspeaker unit to have stable sensitivity.
Here tell about sensitivity adjusting.Fig. 3 shows the structure of sensitivity adjusting equipment of the sensitivity of the capacitor loudspeaker unit that is used for regulating first embodiment.Sensitivity adjusting equipment comprises signal generator 31, loudspeaker 32, capacitor loudspeaker unit 33 and inspection and regulon 34.
For example, signal generator 31 is for being used to generate the equipment of the signal that has preset frequency.It generates and the corresponding signal of reference tone reftone in sensitivity adjusting.Loudspeaker 32 will be supplied to capacitor loudspeaker unit 33 as actual tone by the signal that signal generator 31 generates.Because capacitor loudspeaker unit 33 is identical with capacitor loudspeaker unit shown in Figure 1, therefore it is not told about in detail here.Check with regulon 34 and measure from the signal and the voltage supply circuit 1 of the output value of setting of the output of capacitor loudspeaker unit to be stored to the capacitor loudspeaker unit.Check with regulon 34 and comprise comparer 341, reference circuit 342 and conditioning signal maker 343 etc.
In the sensitivity adjustment method of first embodiment, signal generator 31 and loudspeaker 32 are supplied to capacitor loudspeaker unit 33 with reference tone reftone.Capacitor loudspeaker unit 33 changes into electric signal with reference tone reftone and with its output.33 signals of exporting are supplied to an input end of the comparer 341 inspection and the regulon 34 from the capacitor loudspeaker unit.Another input end of comparer 341 is supplied with the reference voltage that is used for comparison.Reference signal is stored in the reference circuit 342, with as when the input reference tone with its signal level from the output of capacitor loudspeaker unit.The output level of 341 pairs of reference voltages of comparer and capacitor loudspeaker unit compares, and comparative result is outputed to conditioning signal maker 343.Conditioning signal maker 343 is determined the change amount of bias voltage according to the difference between the level of the output level of capacitor loudspeaker unit and reference voltage.Then, its output is used to be provided with the value for the treatment of from the voltage of voltage supply circuit 1 output of setting, is the value of setting of the feedback resistance value that is used to be provided with feedback resistor.The value of setting is fed to output voltage in the voltage supply circuit 1 to be provided with part 23 and it is stored in the storer 236.
Fig. 4 shows the sensitivity of capacitor loudspeaker unit and the relation between the bias voltage.Fig. 5 shows from the value of setting of conditioning signal maker 343 outputs and the regulated quantity of bias voltage.
As mentioned above, check and change amount that regulon 34 is determined bias voltage according to the output level and the difference between the reference voltage of capacitor loudspeaker unit.Fig. 4 also shows the relation between sensitivity and the regulated quantity.
For example, if the output signal of capacitor loudspeaker unit is a low level, and sensitivity is lower than the scope of setting, then promotes the bias voltage that is used for the capacitor loudspeaker unit, to improve sensitivity.At this moment, the recruitment of bias voltage also is to be determined by sensitivity and the departure that scope is set.If the capacitor loudspeaker unit is highly sensitive in scope is set, then determine the amount of turning down of the bias voltage of capacitor loudspeaker unit.
If the bias voltage of capacitor loudspeaker is the output level of 24V and capacitor loudspeaker unit represent with Fig. 4 in the corresponding sensitivity of some A, then determine bias voltage to increase 3V.Sensitivity on the some B in the bias voltage increase 3V permission capacitor loudspeaker cell list diagrammatic sketch 4, this is in the scope of setting.Conditioning signal maker 343 generates and corresponding data is set during the high sensitivity pattern, so that bias voltage increases 3V, and it is supplied to storer 236 in the voltage supply circuit 1.Fig. 5 shows the tabulation for the treatment of from the value of setting of conditioning signal maker 343 outputs, to represent such as settings such as " bias voltage+3V in the high sensitivity pattern ".As shown in Figure 5, the value of setting is outputted as 7 serial data.Highest significant position in 7 bit data (MSB) expression is high sensitivity pattern or low sensitivity mode, and from second to the 4th these three are used for selecting one from 7 included switches of first selector 233.The from the 5th to the 7th these three be used for from 7 included switches of second selector 234, selecting one.As mentioned above, feedback resistance value is by selecting the switch in each selector switch to determine, thereby bias voltage obtains being provided with.
Since can be in the range of adjustment of ± 3V in high sensitivity pattern and low sensitivity mode be that unit regulates bias voltage with 1V, so present embodiment has used 7 bit data.But, figure place can change according to number of the voltage amount of setting or scope and sensitivity mode etc.
Like this, the sensitivity adjusting equipment of first embodiment value of setting of being identified for voltage supply circuit 1 according to the output and the difference between the reference voltage of capacitor loudspeaker unit.Data are stored in the storer 236 in the voltage supply circuit 1.Thereby the capacitor loudspeaker unit that the sensitivity that can generate each unit wherein can wide variation.
Refer back to Fig. 2, come to tell about in detail to be used to receive the structure of the data processor 235 of 7 bit data below.Data processor 235 comprises 7 grades of shift registers as shown in Figure 6.Shift register is supplied with the corresponding 7 bit serial data of the aforesaid value of setting with from the clock of outside in sensitivity adjusting operation.The negative edge synchronised of shift register and clock is accepted serial data successively, has therefore accepted 7 all bit serial data in 7 clocks.The output of obtaining each grade of shift register when accepting 7 bit serial data allows serial data is changed into parallel data.In Fig. 6, output terminal 61～67 is as the output terminal of parallel data.
Be connected to the storer that is used for first selector 233 with second, third and the corresponding output terminal 62,63 and 64 of the 4th numerical digit respectively.Be connected to the storer that is used for second selector 234 with the corresponding output terminal 65,66 and 67 of the 5th, the 6th and the 7th numerical digit respectively.
Fig. 7 is a circuit diagram, show from the structure of the switch of first selector 233 corresponding storeies 236 to the first selector 233.As shown in Figure 7, the storer 236 among first embodiment is by forming at the shift register of data processor and the fuse element between the selector switch.Have three fuse elements 711,712 and 713 with first selector 233 corresponding storeies 236, and on-off element 721,722 and 723.Fuse and switch are connected between power lead and ground.On-off element is connected to the ground connection side with respect to fuse element, and high resistance device 731,732 and 733 and on-off element be in parallel, be connected between fuse element and the ground.On-off element 721,722 and 723 grid receive respectively be converted into parallel data with second, third and the corresponding data of the 4th numerical digit.Therefore, on-off element 721,722 and 723 is connected respectively to parallel data output terminal 62,63 and 64 as shown in Figure 6.Suppose to be supplied with the corresponding signal that is provided with aforesaid " in the high sensitivity pattern bias voltage improve 3V " here, promptly second numerical digit is that 1 and third and fourth numerical digit is 0, as shown in Figure 5.This has only connected the corresponding on-off element 721 in position with second numerical digit, and disconnects other on-off elements 722 and 723.During sensitivity adjusting, in this state, supply fuse open circuit voltage VBIAS from checking with regulon.Exactly, when regulating sensitivity, power lead is connected to fuse open circuit voltage VBIAS.If supply fuse open circuit voltage VBIAS, then excess current is only flowed through and is connected to the fuse element 711 that is on state of switch element 721, thereby cuts off fuse element 711.Because on-off element 722 and 723 is in the off state and respectively only by high resistance device 732 and 733 ground connection, so excess current other fuse elements 712 and 713 of not flowing through.After fuse opened circuit, fuse open circuit voltage VBIAS separated with power lead.
In first embodiment, the above-mentioned value of setting is stored as the fuse off state.Here tell about routine operation.In routine operation, power lead is connected to custom circuit power vd D, and only cuts off fuse 711.In storer 236, the node (on-off element) between fuse element and the high resistance device is connected to the logical circuit in the first selector 233, is the AND gate circuit of 7 switches in the selector switch that is connected in the example shown in Figure 7.In this case, and the node between corresponding fuse element 711 of fuse cut part and the high resistance device 731 is in ground voltage (low level), and wherein fuse do not have cut fuse element 712 and 713 and high resistance device 732 and 733 between node be in high power supply voltage (high level).Therefore, in the circuit of Fig. 7, the switch of selector switch is by all being in the AND gate circuit of high level from all inputs wherein, being the AND gate circuit on the limit that keeps left most that is in Fig. 7, the output high level select.
Though Fig. 7 only shows and being connected of first selector 233 corresponding storeies and first selector 233, be formed for the storer of forming by fuse 236 of second selector 234 in an identical manner, so that store the value of setting by cutting off fuse.
Like this, the value of setting by the sensitivity adjusting operation setting is stored in output voltage and is provided with in the part 23, and generates bias voltage according to the value of setting.
As mentioned above, the value of setting that present embodiment is operated the sensitivity that is identified for being provided with the capacitor loudspeaker unit by sensitivity adjusting, and this value stored into the voltage supply circuit that is used for capacitor loudspeaker.Because the voltage supply circuit of capacitor loudspeaker is provided with feedback resistance value according to the value of setting, therefore can generate capacitor loudspeaker unit without any sensitivity variations.And then, because bias voltage is the voltage that is amplified from reference voltage by non-inverting amplifier, therefore can supply stable bias voltage with lower pulsation.
Second embodiment
Fig. 8 shows the capacitor loudspeaker unit according to second embodiment of the invention.In Fig. 8, be denoted by the same reference numerals with the first embodiment components identical, and no longer it told about here.
The difference of second embodiment and first embodiment is the structure of first feedback resistor 831, second feedback resistor 832, first selector 833 and second selector 834.In the feedback resistor 231 and 232 of first embodiment, a plurality of resistor in series, and switch is connected to the node between the resistor.On the other hand, in the feedback resistor 831 and 832 of second embodiment, 7 resistor parallel connections, and 1 resistor and 7 resistor in series.One end ground connection of resistor.Though each first and second selector switch 833 and 834 has 7 switches as first embodiment, connected mode difference.One end of each on-off element is connected to the resistor of ground connection and the node between 7 resistors in parallel.The other end of each switch is connected to the non-inverting input of non-inverting amplifier 221.
In this embodiment, the resistance value of 7 resistors that distribute in parallel differs from one another.Similar to first embodiment, data processor 235 supply values of setting are used for selecting 1 from 7 switches of selector switch 833 and 834.Therefore, any one of 7 resistors with different resistance values is connected to the inverting input of the non-inverting amplifier among second embodiment.Like this, second embodiment is provided with feedback resistance value by selecting any one and be connected to inverting input from the resistor with different resistance values.
Because first embodiment connects the arbitrary node between the resistor that is in series, therefore be difficult to accurately be provided with the amplification degree of non-inverting amplifier.For example, if the output of non-inverting amplifier and the number that is connected to the resistor between the node of inverting input are 1 in first embodiment, the resistor number that links to each other between then from the node to ground is 7.If the output of non-inverting amplifier and the number that is connected to the resistor between the node of inverting input are 2, the resistor number that links to each other between then from the node to ground is 6.Since the amplification degree of amplifier 221 be according to the resistance value of the feedback resistor that is connected to inverting input and be connected inverting input and ground between the rate of change of resistance value of resistor, therefore the setting of the resistance value of each resistor that is in series in first embodiment is very complicated.Therefore be difficult to accurately regulate bias voltage sometimes.On the other hand, in the structure of the voltage supply circuit 1 of second embodiment, be easy to regulate the resistance value of the feedback resistor that is connected to inverting input and be connected inverting input and ground between the ratio of resistance value of resistor, thereby improved the accuracy that bias voltage is set.
The 3rd embodiment
Fig. 9 shows the capacitor loudspeaker unit according to third embodiment of the invention.In Fig. 9, be denoted by the same reference numerals with the first embodiment components identical, and no longer it told about here.
In the 3rd embodiment, it is a feedback resistor 91 and a resistor 92 that first and second feedback resistors and first and second selector switchs are concentrated respectively.Feedback resistor 91 comprises the resistor of a plurality of series connection.Selector switch 92 comprises the node that is connected between the resistor and a plurality of switches between the inverting input.The voltage supply circuit 1 of the 3rd embodiment is determined feedback resistance value by being combined in the selector switch 92 selected switch.
Though first embodiment is by selecting one feedback resistance value is set from 7 switches that are connected to 8 nodes between the resistor, the 3rd embodiment can treat that the data of the value of setting that is set up and the corresponding relation of selected switch select a plurality of switches by change in sensitivity adjusting.
For example, increase the figure place treat the data that in sensitivity adjusting, are set up, with corresponding with the switch number in the selector switch.Then, when regulating sensitivity, with the value of setting of the corresponding figure place of switch number be that basis treats that the voltage-regulation amount in high sensitivity pattern and low sensitivity mode stores.During routine operation, come to determine the resistor of feedback resistor and the node between the inverting input according to the value of setting and connect for each switch in the selector switch.
If 8 resistor in series and 7 switches are to be formed in the same manner as in the first embodiment in the selector switch, then selector switch has 128 kinds of methods.In this case, value of setting in storer to be stored is the data splitting of switch in the high sensitivity pattern, and is the data splitting of switch in low sensitivity mode.Therefore, the value of setting that obtains in sensitivity adjusting is and corresponding 7 bit data of each switch, and 7 bit patterns of two kinds of patterns of storer 236 storages.Be stored in the corresponding relation of the value of setting and switch in the storer by change, can in high sensitivity pattern and low sensitivity mode, share feedback resistor and selector switch, and bias voltage is set by a feedback resistor 91 and a selector switch 92.
The 4th embodiment
Figure 10 shows the capacitor loudspeaker unit according to fourth embodiment of the invention.In Figure 10, be denoted by the same reference numerals with the first embodiment components identical, and no longer it told about here.
In the 4th embodiment, logarithmic amplifier 1001 is connected to the output of non-inverting amplifier 221.The 4th embodiment further amplifies the voltage from non-inverting amplifier 221 outputs by the amplifier that is called logarithmic amplifier, and it is supplied to capacitor loudspeaker 2 as bias voltage.Logarithmic amplifier is for wherein exporting the amplifier that increases with exponential manner with respect to input.
In the 4th embodiment, logarithmic amplifier 1001 has operational amplifier, diode, bipolar transistor and resistor.The non-inverting input of operational amplifier receives the output of non-inverting amplifier 221 by input resistor.The non-inverting input of operational amplifier passes through resistance-grounded system.The output of operational amplifier feeds back to inverting input by output resistor and diode connected in parallel and bipolar transistor.Logarithmic amplifier 1001 receives the voltage that promotes by the power supply stepup transformer, as supply voltage.
In general, when the bias voltage that is used for the capacitor loudspeaker unit rose, the sensitivity of capacitor loudspeaker unit was risen with exponential manner.Therefore, the 4th embodiment has used the basic logarithmic amplifier identical with the characteristic of the capacitor loudspeaker that is used for bias voltage of input-output characteristic.
In logarithmic amplifier, output changes with exponential manner with respect to input and increases, as mentioned above.For example, in the voltage supply circuit of first embodiment, non-inverting amplifier is regulated the bias voltage that is used for capacitor loudspeaker in the scope of ± 3V.But because the 4th embodiment amplifies the output of non-inverting amplifier by logarithmic amplifier, can be in greater than the scope of ± 3V the adjusting bias voltage.
Optional embodiment
Though have the storer of three fuse elements in first embodiment is that storer 236 is selected any one from 7 switches, can use another structure to be used for storer.Figure 11 shows and wherein uses the situation of another circuit as storer.Though storer 236 is between data processor 235 and selector switch 233 in first embodiment, storer is in parallel with feedback resistor in this optional embodiment.Fuse is in parallel with a plurality of resistors of feedback resistor.
Then, cut off any fuse of 7 fuses according to the voltage-regulation amount in the sensitivity adjusting operation.Can form storer by making fuse placement in parallel and during sensitivity adjusting, cutting off fuse like this with feedback resistor.This structure is applicable to any of second to the 4th embodiment.Figure 12 shows the situation that wherein another optional embodiment is applied to second embodiment.Storer shown in Figure 12 is by being placed on fuse between each feedback resistor and the switch and cutting off any fuse and store the value of setting during sensitivity adjusting.
Though the foregoing description forms storer by using fuse, storer is not limited to fuse element, also can use Zener breakdown device (Zener-zap) or EEPROM.The Zener breakdown device is the operation element opposite with fuse.Fuse makes 2 disconnections always store data by cut-out, and the Zener breakdown device makes 2 short circuits always store data by puncturing.For example, sort memory can be implemented by the fuse of replacing optional embodiment shown in Figure 11 with Zener breakdown device element.
Figure 13 is a circuit diagram, shows the structure of wherein replacing the fuse of the storer that is used to form first embodiment shown in Figure 7 with EEPROM.For in the circuit of structure, obtain with Figure 13 with first embodiment in the identical output of storer, during sensitivity adjusting, high voltage is put on as the Vwrite that writes voltage.And then, low level signal is supplied to the control grid of EEPROM element 1321, and high level signal is supplied to the control grid of EEPROM element 1322 and 1323.As a result, in EEPROM element 1321, the electronics on the floating gate is discharged, so that it is in normal on attitude.On the other hand, in EEPROM element 1322 and 1323, the electronics on the floating gate is not discharged, so that it rests on erase status.Owing to after finishing sensitivity adjusting operation, any voltage is not put on Vwrite and control grid, so be in that the element of erase status always disconnects, and only low level signal be supplied to the phase inverter at the most left place that is in Figure 13.Therefore, only be in the AND gate circuit output high level on the limit that keeps left most of Figure 13, to select identical switch in the situation with first embodiment.
Though power supply stepup transformer 21 rises to constant level with supply voltage and no matter mode designating signal how, also can be input to mode designating signal power supply stepup transformer 21, so that its voltage required according to the mode producing amplifier in the above-described embodiments.
The 5th embodiment
Figure 14 shows the capacitor loudspeaker unit according to fifth embodiment of the invention.In this embodiment, discharger 1401 and the timer 1410 that is used for capacitor loudspeaker 2 are added to the voltage supply circuit 1 of first to fourth embodiment and optional embodiment.In this embodiment, voltage supply circuit 1, resistor 5, discharger 1401 and timer 1410 form a LSI chip (semiconductor devices).This embodiment refers to the structure that forms in a chip as power circuit.In Figure 14, be denoted by the same reference numerals with the first embodiment components identical, and no longer it told about here.
As described in first embodiment of reference Fig. 1, will be supplied to capacitor loudspeaker 2 by resistor 5 from the bias voltage of voltage supply circuit 1 output.The resistance value of resistor 5 can be for example about 1～10G Ω, and resistance value is about 1G Ω under the preferable case.Because the grid impedance of JFET 3 is very big, therefore needs to place resistor and make itself and impedance matching.The discharger 1401 of present embodiment is connected between the node A and ground between resistor 5 and the capacitor loudspeaker 2.
Tell about the operation of the discharger 1402 among the 5th embodiment referring now to Figure 15.As mentioned above, when applying supply voltage, timer 1410 receives control signal and the discharge switch 1403 of closed discharger 1401 in the section (D1) at the fixed time from the outside.Thereby fast electric charge remaining in the capacitor loudspeaker is discharged, this can not cause noise.When interrupting power circuit, before supply voltage descends also from outside supply control signal.Timer 1410 receives control signals and closed discharger 1401 in the section (D2) at the fixed time, thereby fast electric charge remaining in the capacitor loudspeaker is discharged.
Tell about the situation that does not have discharger 1401 in the present embodiment now.If there is not discharger 1401, then be stored in electric charge in the capacitor loudspeaker is discharged into voltage supply circuit 1 by the high resistance device 5 that is used for impedance matching ground.But, discharge because electric charge is an interior circuit by high resistance device 5 and voltage supply circuit 1, therefore this discharging is extremely slow.If electric charge remains in the capacitor loudspeaker 2, then the discharging of gate charge that is connected to the JFET 3 of capacitor loudspeaker 2 by capacitor 4 also is very slowly.If capacitor loudspeaker 2 repeats to switch on and off during electric charge shifts, then the switching of ON and OFF can cause noise.
For example, if as described in first to fourth embodiment, capacitor loudspeaker allows to switch between high sensitivity pattern and low sensitivity mode, then when when high sensitivity pattern (bias voltage is 24V) switches to low sensitivity mode (bias voltage is 12V), the discharge of the grid of capacitor loudspeaker 2 and JFET 3 is inadequate, therefore can cause noise.
On the other hand, in the present embodiment, the ON of discharger power source-responsive and OFF or mode designating signal, quick drain remains in the electric charge in the capacitor loudspeaker.Even thereby when carrying out power source ON/OFF switching or mode switch, also can under the situation that does not cause noise, switch at the discharge transition period.Exactly, as D1 and D2, being arranged so that of timer with about 1～100 microsecond of switch closure.
Therefore, even the resistance value of the resistor corresponding with the input impedance of JFET 35 is very high, use the power circuit of present embodiment also can guarantee discharge.If do not use the discharger of present embodiment, then the resistor of being made up of for example polysilicon is connected between grid and the source electrode, to eliminate the gate charge of JFET, is used to reduce noise.But, if because the resistance value of the grid of JFET and the resistor between the source electrode is too low thermonoise can take place, discharge effect can be very low if resistance value is too high, and therefore this situation needs point-device resistance control.Because micropkonic operating under the situation that does not have the resistor between grid and the source electrode without any problem, so present embodiment allows to remove resistor.Therefore, with regard to not needing grid and the polyresistor between the source electrode at JFET are carried out strict resistance control.Much less, use resistor also to be fine.
The 6th embodiment
Tell about the sixth embodiment of the present invention referring now to Figure 16 and 17.Figure 16 shows according to the microphone unit of the 6th embodiment and power circuit 160.The power circuit of the 5th embodiment discharges to capacitor loudspeaker when power supply carries out the switching of ON and OFF or from the high sensitivity mode switch to low sensitivity mode the time.The circuit of present embodiment also can respond from low sensitivity mode and switch to the high sensitivity pattern.Therefore, the difference of present embodiment and the 5th embodiment is also have charger 1601 except having discharger 1401, and has the timer 1610 of the open and close time of the switch that is used to control discharger 1401 and charger 1601.
Though Figure 16 only shows a timer 1610 in the module in order to simplify, and in fact two timers are arranged, one is used for 1401, one of open and close dischargers and is used for open and close charger 1601.There are two signal line from timer 16.Charger 1601 has charging resistor 1602 that resistance is about 100～1000k Ω and the switch of being made up of P type MOSFET 1603.Charger 1601 is inserted between the output and node A of voltage supply circuit 1.
Tell about the operation of timer 1610 and switch below.The resistance of charging resistor and discharging resistor is about 100～1000k Ω under the preferable case.
As previously mentioned, voltage supply circuit 1 allows to carry out the sensitivity switching.For example, the sensitivity switching is what appropriately to select according to the distance between user and the loudspeaker.For example,, then improve sensitivity, if the too close loudspeaker of user, then desensitization (the conventional setting) if the user is too far away from loudspeaker.Too far or too near definition can be provided with different modes.For example, in mobile phone etc., when the user was seeing display screen or taking phone to converse without hand, then detecting distance be far away and raising sensitivity.On the other hand, when the user conversed in one's ear by mobile phone is placed on, just when user's face can not be identified on display screen, then detecting distance was nearer and desensitization.Therefore be according to user's face whether on display screen, whether take phone to wait to judge and the output sensitivity switching signals such as CPU of mobile phone with hand.Thereby improve or reduce bias voltage, to change sensitivity.
In this case, according to circumstances improve and reduce bias voltage continually, and it is even more important to discharge.And then, consider from low sensitivity mode to switch to the high sensitivity pattern, carry out rapid charge under the preferable case.Present embodiment uses charger to be used for pattern wherein switches to high sensitivity pattern etc. from low sensitivity mode situation.
Tell about the operation of the 6th embodiment below with reference to the sequential chart of Figure 17.In the capacitor loudspeaker unit of present embodiment, timer 1610 moves when receiving the sensitivity switching signal.According to the signal from timer 1610 outputs, charger 1601 and discharger 1401 move in the section at the fixed time.As mentioned above, timer 1610 comprises the timer that is used to charge and the timer that is used to discharge, and predetermined amount of time C1 and predetermined amount of time C2 are about 1～100 microsecond.
For example, when in order to switch micropkonic sensitivity when improving the output voltage of voltage supply circuit 1 by outside switching signal, the switch 1603 of charger 1601 is connected in the section C1 at the fixed time.Create by timer internal at interval.By connecting switch and closed circuit, the grid to capacitor loudspeaker 2 and JFET 3 charges at once.Thereby can eliminate time lag as the problems of the prior art.
Sequential chart below with reference to Figure 17 further tells about in detail this operation.For example, be used for bias voltage when about 12V rises to the sensitivity switching signal of about 24V receiving, switch 1603 closures of charger 1601, and the output of voltage supply circuit 1 is fed to high resistance device 5.Simultaneously, Active Timer 1610 is to carry out rapid charge by charging resistor 36 in about 1～100 microsecond.When predetermined duration of charging section finishes, open switch 1603, to open charger 35.Aforesaid operations is an example, and is used in switching under the situation of sensitivity of two or more (a plurality of) predetermined electrical bias voltage, and when promoting bias voltage, the mode of operation of charger is identical.
On the other hand, be used for bias voltage when about 24V is reduced to the sensitivity switching signal of about 12V receiving, discharger 1401 operations, and switch 1403 closures are to carry out rapid discharges by discharging resistor 31.The time period of Closing Switch 1403 also is the decision that is provided with by timer 1610, and about 1～100 microsecond is for example carried out in rapid discharge.When change being provided with when reducing magnitude of voltage or reducing the sensitivity of from a plurality of predetermined electrical bias voltage, selecting, use this discharge to be used as the rapid discharge operation.Therefore, present embodiment has discharger and is used as the rapid discharge device.
This does not just need to place the high resistance device that resistance is about 1G Ω between the grid of necessary JFET in the discharge that is used for capacitor loudspeaker and JFET grid in the existing structure and the source electrode.Thereby the noise that caused by the high resistance device can not take place, therefore improved sound quality and characteristic.And then the high resistance device of biasing, capacitor loudspeaker and JFET grid form the low-pass filter structure, thereby have also reduced to be positioned at wow flutter outside the range of audibility etc.
Power circuit can form a LSI chip or semiconductor devices.In this case, when when output terminal is seen, resistor is connected with charger, bias power supply circuit and discharger, thereby the static discharge tolerance limit of the output terminal of the power circuit that does not show among the figure increases.
The 7th embodiment
Control timing figure below with reference to Figure 18 tells about the seventh embodiment of the present invention.The 7th embodiment is identical with the 6th embodiment on circuit structure.The same with first embodiment, the 7th embodiment control is in the rising of supply voltage and along the discharger 1401 of negative edge.Exactly, controller (CPU) is connected the switch 1403 of discharger 1401 on the rising edge of supply voltage and negative edge, so that stop at once bias voltage is supplied to capacitor loudspeaker.
Thereby can prevent that the transition overshoot voltage that will be in the biasing application from offering capacitor loudspeaker, therefore suppressed noise.In addition in this case, the time of Closing Switch is provided with by timer.
The time that timer 1601 is provided with under the preferable case is that time D3 and D4 are the time that transition biasing fluctuation takes place in voltage rising and decline process.Though exactly be according to the decision of the characteristic of each power supply, be used for that voltage rises and the time period of decline is identical basically.Say more compactly, can be the same with time period D1 and the D2 among the 5th embodiment, with the time of about 1～100 microsecond of switch closure.Also can make it identical, be about 1～100 microsecond with time period D2 among the 6th embodiment.
The 8th embodiment
Tell about the eighth embodiment of the present invention below with reference to Figure 19.Present embodiment uses charge/discharge switch 1901 to be used as the rapid discharge device.Charge/discharge switch 1901 is parallel-connected to the two ends of high resistance device 5.Be about 100～1000k Ω because the output impedance of voltage supply circuit 1 is low usually,, then can carry out charging and discharge at short notice if therefore walk around high resistance device 5 by switch 1901.And then, between the output terminal that the resistor 1902 that resistance value is about 100～1000k Ω does not show in high resistance device 5 and figure.Can remove resistor 1902.
Because this structure puts on bias voltage and is in low-impedance capacitor, so it has substituted the function of charger 1401 and discharger 1601, so that it is as having rapid discharge device and quick charge device.In other words, the output of bias power supply circuit has the push-pull type structure or allows to be used for the structure that the electric current of the bias voltage of capacitor loudspeaker charges and discharges.Then, switch 1901 is connected to the two ends of high resistance device, and when switching bias voltage, and according to from the sensitivity switching signal such as controllers such as CPU, switch is closed at once and and then open.Closing Switch 1901 has got around high resistance device 3, to allow voltage fast rise and decline.
As previously mentioned, voltage supply circuit of the present invention can put on appropriate voltage such as sensors such as capacitor loudspeakers according to level of sensitivity.And then, can reduce sensitivity variations such as each microphone unit of capacitor loudspeaker unit.And then, can be by connecting the generation that charger and discharger suppress noise.
The present invention is not limited to the described structure as above-mentioned embodiment, also can adopt the multiple mode described in optional embodiment to change.
For example, described in the 6th embodiment, the sensitivity of the foregoing description is switched and can suitably be selected according to the distance between user and the loudspeaker.And then though only told about low sensitivity mode and high sensitivity pattern in an embodiment, plural a plurality of sensitivity mode also can be applied in the embodiments of the invention.
And then, wherein use vibration transducer (capacitor loudspeaker) to be used as the situation of the sensor in the voltage supply circuit of the present invention though told about in detail in the above-described embodiments, the application of voltage supply circuit of the present invention is not limited to capacitor loudspeaker.For example, it is for principle of operation and capacitor loudspeaker is similar and other sound pressure sensors of detection capacitance variations also are effectively, for example uses the sensor of semiconductor devices.Therefore, microphone unit of the present invention also comprises the microphone unit of another sound pressure sensor that is used to detect capacitance variations, such as using semiconductor devices as micropkonic microphone unit etc.And then voltage supply circuit of the present invention is very effective for the sensor that detects capacitance variations particularly for change-detection type vibration transducer.Voltage supply circuit of the present invention also is applicable to other sensors that can change output by the DC bias voltage, such as temperature sensor and optical sensor etc.
Clearly, the present invention is not limited to the foregoing description, can revise and change it under the situation that does not depart from scope and spirit of the present invention.
Claims (24)
1. voltage supply circuit comprises:
The power supply stepup transformer;
Amplifier moves as supply voltage with the voltage that generates by the power supply stepup transformer, and is used for bias voltage is supplied to sensor;
Output voltage is provided with part, comprises first feedback resistor and second feedback resistor, and selects a conduct the described resistor to be used for the feedback resistor of amplifier according to the pattern signalization of the outside supply that part is set from output voltage;
Be used to carry out first switching device shifter of first sensitivity adjusting; And
Be used to carry out second switching device shifter of second sensitivity adjusting,
Wherein, can regulate the sensitivity of described sensor by described first sensitivity adjusting and described second sensitivity adjusting, wherein said first sensitivity adjusting is one that selects in described first feedback resistor and second feedback resistor, described second sensitivity adjusting is that each resistor values in described first feedback resistor and second feedback resistor is provided with, and
Wherein, each resistor in the described resistor has the definite resistance of the value of setting according to the bias voltage of sensor.
2. voltage supply circuit as claimed in claim 1 further comprises:
Storer, the value of setting that is used to store bias voltage.
3. voltage supply circuit as claimed in claim 1, wherein,
Each resistor in the described resistor has the resistance by optional resistor decision from a plurality of resistors.
4. voltage supply circuit as claimed in claim 1, wherein,
Each resistor in the described resistor comprises a plurality of resistors, and by using the resistance of determining feedback resistor with the corresponding any number resistor of the value of setting of bias voltage.
5. voltage supply circuit as claimed in claim 2, wherein,
Storer is stored the value of setting of bias voltage by fuse.
6. voltage supply circuit as claimed in claim 2, wherein,
The value of setting that storer is stored bias voltage by the Zener breakdown device.
7. voltage supply circuit as claimed in claim 1,
Wherein, described second switching device shifter further comprises first selector that is connected with first feedback resistor and the second selector that is connected with second feedback resistor,
Wherein, output voltage is provided with part and further comprises and be used for selecting signal provision to give the data processor of described first selector and described second selector, and,
Wherein, each selector switch in described first selector and the described second selector is according to selecting signal that the resistance of described first resistor and described second resistor is set respectively, and with the feedback resistor that acts on amplifier.
8. microphone unit comprises:
Loudspeaker is used to receive bias voltage;
The power supply stepup transformer;
Amplifier moves as supply voltage with the voltage that generates by the power supply stepup transformer, and is used for bias voltage is supplied to loudspeaker;
Output voltage is provided with part, comprises first feedback resistor and second feedback resistor, and selects a conduct the described resistor to be used for the feedback resistor of amplifier according to the pattern signalization of the outside supply that part is set from output voltage;
Be used to carry out first switching device shifter of first sensitivity adjusting; And
Be used to carry out second switching device shifter of second sensitivity adjusting,
Wherein, can regulate described micropkonic sensitivity by described first sensitivity adjusting and described second sensitivity adjusting, wherein said first sensitivity adjusting is one that selects in described first feedback resistor and second feedback resistor, described second sensitivity adjusting is that each resistor values in described first feedback resistor and second feedback resistor is provided with, and
Wherein, each resistor in the described resistor has the definite resistance of the value of setting according to the bias voltage of sensor.
9. microphone unit as claimed in claim 8 comprises:
Storer, the value of setting that is used to store bias voltage.
10. power circuit that is used for bias voltage is supplied to microphone unit, wherein, microphone unit comprises amplifier, capacitor and capacitor loudspeaker, described power circuit comprises:
Voltage supply circuit is used for generating predetermined electrical bias voltage and bias voltage being supplied to capacitor loudspeaker by resistor according to the voltage from the outside supply;
Resistor, the one end is connected to the output terminal of voltage supply circuit; And
Discharger, the one end is connected to the other end of resistor, and the other end is connected to one of the earth terminal of power circuit or output terminal of voltage supply circuit,
Wherein, described voltage supply circuit comprises:
The power supply stepup transformer;
Amplifier moves as supply voltage with the voltage that generates by the power supply stepup transformer, and is used for bias voltage is supplied to capacitor loudspeaker;
Output voltage is provided with part, comprises first feedback resistor and second feedback resistor, and selects a conduct the described resistor to be used for the feedback resistor of amplifier according to the pattern signalization of the outside supply that part is set from output voltage;
Be used to carry out first switching device shifter of first sensitivity adjusting; And
Be used to carry out second switching device shifter of second sensitivity adjusting,
Wherein, can regulate the sensitivity of described capacitor loudspeaker by described first sensitivity adjusting and described second sensitivity adjusting, wherein said first sensitivity adjusting is one that selects in described first feedback resistor and second feedback resistor, described second sensitivity adjusting is that each resistor values in described first feedback resistor and second feedback resistor is provided with, and
Wherein, each resistor in the described resistor has the definite resistance of the value of setting according to the bias voltage of capacitor loudspeaker.
11. power circuit as claimed in claim 10, wherein,
Discharger and comprises discharging resistor and discharge switch between the earth terminal of the other end of high resistance device and power circuit.
12. power circuit as claimed in claim 10, wherein,
The voltage supply circuit response is optionally exported a plurality of bias voltages from the sensitivity switching signal of outside.
13. power circuit as claimed in claim 11 comprises:
First timer makes the discharge switch open and close,
Wherein, first timer response sensitivity switching signal is with discharge switch open and close predetermined amount of time.
14. power circuit as claimed in claim 11 further comprises:
Charger is connected in parallel between the two ends of resistor, and comprises charge switch and charging resistor.
15. power circuit as claimed in claim 14 comprises:
Second timer makes the charge switch open and close,
Wherein, second timer response sensitivity switching signal is with charge switch open and close predetermined amount of time.
16. power circuit as claimed in claim 10, wherein, the discharger that is connected to the other end of high resistance device is the charge/discharge switch that is connected between the two ends of resistor.
17. power circuit as claimed in claim 16, wherein, the voltage supply circuit response is from the sensitivity switching signal of outside, optionally export a plurality of bias voltages, voltage supply circuit comprises the 3rd timer that is used to make charge/discharge switch opens and closure, and the 3rd timer response sensitivity switching signal is with charge/discharge switch opens and closed predetermined amount of time.
18. power circuit as claimed in claim 11 further comprises:
The 4th timer makes the discharge switch open and close,
Wherein, the response of the 4th timer is from the control signal of outside, with discharge switch open and close predetermined amount of time.
19. power circuit as claimed in claim 10, wherein, power circuit is formed in the chip large scale integrated circuit.
20. a microphone unit comprises power circuit as claimed in claim 10.
21. power circuit as claimed in claim 10, voltage supply circuit comprises:
The power supply stepup transformer;
Amplifier moves as supply voltage with the voltage that generates by the power supply stepup transformer, and is used for bias voltage is supplied to sensor; And
Output voltage is provided with part, comprises the feedback resistor that is used for amplifier, and the resistance of this feedback resistor is to determine according to the value of setting of the bias voltage of sensor.
22. power circuit as claimed in claim 10, voltage supply circuit comprises:
The power supply stepup transformer;
Amplifier moves as supply voltage with the voltage that generates by the power supply stepup transformer, and is used for bias voltage is supplied to sensor;
Output voltage is provided with part, comprises the feedback resistor that is used for amplifier, and the resistance of this feedback resistor is to determine according to the value of setting of the bias voltage of sensor; And
Storer, the value of setting that is used to store bias voltage.
23. power circuit as claimed in claim 10, voltage supply circuit comprises:
The power supply stepup transformer;
Amplifier moves as supply voltage with the voltage that generates by the power supply stepup transformer, and is used for bias voltage is supplied to sensor;
Output voltage is provided with part, comprises the feedback resistor that is used for amplifier, and the resistance of this feedback resistor is to determine according to the value of setting of bias voltage.
Wherein feedback resistor comprises first feedback resistor and second feedback resistor at least, and selects a conduct first feedback resistor and second feedback resistor to be used for the feedback resistor of amplifier according to the pattern signalization of the outside supply that part is set from output voltage.
24. one kind is used to regulate micropkonic sensitivity of method, comprises:
Reference tone reftone is input to loudspeaker;
Micropkonic output and the reference voltage that is used for reference tone reftone compared;
Export the value of setting according to comparative result, this value of setting is used to be provided with the bias voltage to the loudspeaker bias voltage; And
Storage value of setting and be identified for the feedback resistance value of the amplifier of output offset voltage according to the value of setting, wherein,
Select a conduct the first feedback resistor value and the second feedback resistor value to be used for the feedback resistance value of amplifier according to the pattern signalization of the outside supply that part is set from output voltage.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2005001380 | 2005-01-06 | ||
| JP2005001380A JP4390716B2 (en) | 2005-01-06 | 2005-01-06 | Voltage supply circuit, microphone unit and method for adjusting sensitivity of microphone unit |
| JP2005285002 | 2005-09-29 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1828469A CN1828469A (en) | 2006-09-06 |
| CN100587646C true CN100587646C (en) | 2010-02-03 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200610005754A Expired - Fee Related CN100587646C (en) | 2005-01-06 | 2006-01-06 | Voltage supply circuit, power supply circuit, microphone unit, and sensitivity adjustment method |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP4390716B2 (en) |
| CN (1) | CN100587646C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103328932A (en) * | 2011-02-28 | 2013-09-25 | 富士电机株式会社 | Semiconductor integrated circuit and semiconductor physical quantity sensor device |
Families Citing this family (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4722655B2 (en) * | 2005-09-29 | 2011-07-13 | ルネサスエレクトロニクス株式会社 | Power supply circuit and microphone unit using the same |
| US8170237B2 (en) * | 2005-07-19 | 2012-05-01 | Audioasics A/S | Programmable microphone |
| JP5097511B2 (en) * | 2007-11-19 | 2012-12-12 | 株式会社船井電機新応用技術研究所 | Voice input device, manufacturing method thereof, and information processing system |
| JP5067838B2 (en) * | 2007-01-31 | 2012-11-07 | 株式会社オーディオテクニカ | Microphone power supply |
| JP2009087293A (en) * | 2007-10-03 | 2009-04-23 | Nec Electronics Corp | Stabilized power supply circuit |
| US8401208B2 (en) * | 2007-11-14 | 2013-03-19 | Infineon Technologies Ag | Anti-shock methods for processing capacitive sensor signals |
| JP5320784B2 (en) * | 2008-03-24 | 2013-10-23 | ソニー株式会社 | Signal processing apparatus and signal processing method |
| US8666095B2 (en) | 2008-05-05 | 2014-03-04 | Epcos Pte Ltd | Fast precision charge pump |
| JP2009284110A (en) * | 2008-05-20 | 2009-12-03 | Funai Electric Advanced Applied Technology Research Institute Inc | Voice input device and method of manufacturing the same, and information processing system |
| JP5166117B2 (en) * | 2008-05-20 | 2013-03-21 | 株式会社船井電機新応用技術研究所 | Voice input device, manufacturing method thereof, and information processing system |
| JP2009284111A (en) | 2008-05-20 | 2009-12-03 | Funai Electric Advanced Applied Technology Research Institute Inc | Integrated circuit device and voice input device, and information processing system |
| TWI385573B (en) * | 2008-08-27 | 2013-02-11 | Realtek Semiconductor Corp | Audio device and audio input/output method |
| CN102055419A (en) * | 2010-11-30 | 2011-05-11 | 中国船舶重工集团公司第七一五研究所 | High-efficiency linear power amplifier for underwater acoustic communication |
| CN104168529B (en) * | 2013-05-17 | 2018-08-28 | 上海耐普微电子有限公司 | The micromachined microphones of multi-mode |
| JP6310317B2 (en) * | 2014-04-25 | 2018-04-11 | ローム株式会社 | Microphone bias circuit, audio interface circuit, electronic equipment |
| CN105843316B (en) * | 2016-05-31 | 2017-10-24 | 上海华虹宏力半导体制造有限公司 | Charge pump reference voltage adjusts circuit |
-
2005
- 2005-01-06 JP JP2005001380A patent/JP4390716B2/en not_active Expired - Fee Related
-
2006
- 2006-01-06 CN CN200610005754A patent/CN100587646C/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103328932A (en) * | 2011-02-28 | 2013-09-25 | 富士电机株式会社 | Semiconductor integrated circuit and semiconductor physical quantity sensor device |
| CN103328932B (en) * | 2011-02-28 | 2015-08-05 | 富士电机株式会社 | SIC (semiconductor integrated circuit) and semiconductor physical quantity sensor device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1828469A (en) | 2006-09-06 |
| JP4390716B2 (en) | 2009-12-24 |
| JP2006191359A (en) | 2006-07-20 |
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