CN1969401B - Transconductance circuit for piezoelectric transducer, Piezoelectric detector and its package - Google Patents
Transconductance circuit for piezoelectric transducer, Piezoelectric detector and its package Download PDFInfo
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- CN1969401B CN1969401B CN2005800108689A CN200580010868A CN1969401B CN 1969401 B CN1969401 B CN 1969401B CN 2005800108689 A CN2005800108689 A CN 2005800108689A CN 200580010868 A CN200580010868 A CN 200580010868A CN 1969401 B CN1969401 B CN 1969401B
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Abstract
A transconductance monitoring and amplifying circuit for a piezoelectric transducer (22, 28, 34, 40) that may be used in, e.g., a motion detector system includes a FET (Q1), with the transducer (22, 28, 34, 40) (and, hence, the signal voltage reference) floating between the gate and source of the FET (Q1), as opposed to being connected to the common ground of the circuit. This permits the development of a larger detector signal and concomitantly the use of a relatively inexpensive FET (Q1) instead of a relatively more expensive high impedance operational amplifier as must be used in conventional transconductance circuits. The FET (Q1) and transducer (22, 28, 34, 40) can be held in a single four-pin package (54).
Description
Technical field
A kind of PZT (piezoelectric transducer) of relate generally to of the present invention system.
Background technology
Piezoelectric sensor systems is used in using widely.Only as a unrestriced example, some safety systems use passive infrared (PIR) motion sensors to detect moving in monitored space, the variation of the far infrared radiation (8-14 micron wave length) that described sensor causes owing to the temperature difference between object (for example people) and its background environment.When detecting, motion sensor sends indication usually to host computer system, and host computer system can transfer to activate and invade " alarm ", changes room lighting, opens door or carry out some other functions.Advantageously, this transducer is simple and relatively cheap.
The detector of pir sensor can comprise pyroelectric detector, and it measures the variation of far infrared radiation.This detector comes work by " piezoelectric effect ", and described piezoelectric effect causes charge migration under the situation that mechanical strain exists.Pyroelectric detector adopts form---two conductive plates that separated by dielectric of capacitor.Dielectric can be a piezoelectric ceramic.When far infrared radiation caused ceramic variations in temperature (and thereby have some mechanical strains), electric charge was moved to another plate from a plate.If there is not external circuit (perhaps very the circuit of high impedance) to be connected to detector (" voltage output mode "), then measurable voltage shows as " capacitor " electric charge.If low-impedance relatively external circuit is connected (" electric current output mode ") between the described plate, then electric current flows.
Piezoelectric detector under the electric current output mode is placed in the transconductance amplifier circuit, wherein, as substituting that the voltage between the plank that allows transducer changes basically, electric charge is used to set up the voltage of circuit output signal with establishment by the feedback resistor conduction of high input impedance operational amplifier.So-called " height " impedance is meant at least 10
7The impedance of ohm.
The present invention relates to provide the cheap version of transconductance circuit.As understood here, because must measure the electric charge that is produced by described piezoelectric detector on a small quantity, the transconductance circuit of piezoelectric detector before requires relatively costly high input impedance operational amplifier.As further understanding of institute here, can utilize the inventive concept here that more cheap circuit is provided.
Summary of the invention
The some versions of transconductance circuit is disclosed, the piezoelectricity far infrared radiation detector that for example can realize in the infrared moving transducer.
Thus, piezoelectric detector comprises PZT (piezoelectric transducer) and the transconductance circuit that is electrically connected with this transducer.Transconductance circuit defines common ground and is not directly connected to the signal voltage benchmark of common ground.
In certain embodiments, the mutual conductance resistor can be connected to the grid of field-effect transistor (FET), and transconductance circuit does not have high input impedance operational amplifier.Output resistor can be connected to the source electrode of FET potentially by bipolar junction transistor (BJT), the base stage of bipolar junction transistor can be connected to the source electrode of FET.If desired, provide " short circuit " capacitor of approximate short circuit current the drain electrode of FET can be connected to the source electrode of FET with the sensor signal operating frequency, and, the output feedback loop divider of alternating current (AC) coupling can be connected FET source electrode and with mutual conductance resistor that the grid of FET is connected between.
In specific unrestricted embodiment, the mutual conductance resistor is connected to the grid of FET by standard input impedance operational amplifier.The paraphase input of operational amplifier can be connected to the source electrode of FET, and the input of the noninvert of operational amplifier can be connected to the signal voltage benchmark.And, the output feedback loop divider of AC coupling can be connected operational amplifier output and with mutual conductance resistor that the grid of FET is connected between.
On the other hand, in comprising the mutual conductance detector circuit of PZT (piezoelectric transducer), field-effect transistor (FET) is connected to the transducer that is used to amplify its signal.This circuit also has circuit common ground and signal voltage datum node, and this node is in the AC current potential that is different from ground connection.
In yet another aspect, circuit comprises PZT (piezoelectric transducer) and transconductance amplifier circuit, and the latter receives from the signal of transducer and handles this signal to produce output along electric pathway.Transconductance amplifier circuit does not comprise high input impedance operational amplifier.
In a circuit execution mode, piezoelectric detector comprises PZT (piezoelectric transducer) and is electrically connected to the transconductance circuit of this transducer.As previously mentioned, transconductance circuit comprises the PZT (piezoelectric transducer) of the grid that is connected to field-effect transistor (FET), and transconductance circuit does not have operational amplifier.But transconductance circuit comprises the mutual conductance resistor that is connected to the FET grid and first and second transistors except this FET.In a specific implementations of this last circuit, feedback circuit partly comprises the first transistor and transistor seconds, and transistor seconds is electrically connected to mutual conductance resistor and the first transistor.
On the other hand, piezoelectric detector comprises and held three parts, i.e. PZT (piezoelectric transducer), the field-effect transistor (FET) of definition grid and the shell of the mutual conductance resistor that is connected with grid.First to the 4th electric connector is positioned on the shell and is electrically connected to FET source electrode, FET drain electrode, PZT (piezoelectric transducer) and mutual conductance resistor in the enclosure respectively.Described connector mechanically can be coupled with the circuit element outside the shell.
In a particular embodiment, feedback circuit part circuit can be connected to first connector, so that be connected to the feedback circuit part by the FET source drive.And power circuit can be connected to second connector, so that power supply is connected to the drain electrode of FET.In addition, circuit-line can be connected to the 3rd connector, so that the transconductance circuit of at least a portion is connected to transducer.In addition, feedback line can be connected to the 4th connector, so that at least a portion circuit is connected to the mutual conductance resistor.
In yet another aspect, be used for operationally the method that will engage with transconductance circuit with the PZT (piezoelectric transducer) of the gate coupled of field-effect transistor (FET), be included in PZT (piezoelectric transducer), FET and mutual conductance resistor are provided in the single shell.This method also is included in provides four connectors on the shell, and these connectors is connected to the some parts of transconductance circuit.
Description of drawings
With reference to the accompanying drawings, can understand the details of the present invention best about its structure and operation, in the accompanying drawings, similar part like the invoking marks representation class, and wherein:
Fig. 1 is the block diagram of native system architecture;
Fig. 2 is the schematic diagram of first embodiment of this transconductance circuit;
Fig. 3 is the schematic diagram of second embodiment of this transconductance circuit;
Fig. 4 is the schematic diagram of the 3rd embodiment of this transconductance circuit;
Fig. 5 is the schematic diagram of the 4th embodiment of this transconductance circuit;
Fig. 6 is the schematic diagram of the revision of first embodiment shown in Fig. 2, and wherein the interchange (AC) to transducer is separated from each other to avoid enough higher positions may make the saturated DC output of circuit if be connected with direct current (DC);
Fig. 7 is the schematic diagram of the revision of second embodiment shown in Fig. 3, wherein is connected with DC to the AC of transducer to be separated from each other;
Fig. 8 is the schematic diagram of the revision of the 3rd embodiment shown in Fig. 4, wherein is connected with DC to the AC of transducer to be separated from each other;
Fig. 9 is the schematic diagram of the revision of the 4th embodiment shown in Fig. 5, wherein is connected with DC to the AC of transducer to be separated from each other;
Figure 10 is the schematic diagram of another alternative embodiment of this transconductance circuit; With
Figure 11 is the perspective view of transducer packing.
Embodiment
Initially, the non-limiting system of example is shown, usually represents, be used to detect mobile object 12, such as the people with 10 with reference to figure 1.System 10 comprises optical system 14, and it can comprise that suitable speculum, lens and other are known in the art the parts of image focusing on passive infrared (PIR) detector system 16 that are used for object 12.In response to mobile object 12, PIR detector system 16 generates and can be filtered by signal processing circuit 18, amplification and digitized signal, and treatment system 20 (such as, computer or application-specific IC) receive this signal and determine whether to activate and can hear alarm 21 or other output equipment that maybe can see, such as the activation system that is used for door, or the like.
After having described an application of piezoelectric detector of the present invention, focus on Fig. 2-5 now, they show the various execution modes of notion of the present invention.As shown in Figure 2, PZT (piezoelectric transducer) 22 is provided in the transconductance circuit 24 of (DC) voltage source 26 that has direct current.Circuit 24 can be looked at as the supervisory circuit that is used for PZT (piezoelectric transducer) 22.And circuit 24 impedances bufferings (impedance-buffer) and amplification are from the signal of transducer 22.
According to present principles, " transconductance circuit " is such circuit, and wherein as substituting that the voltage between the plank that allows transducer (for example transducer 22) changes basically, electric charge is used to set up the voltage of circuit output signal with establishment by the resistor conduction.
PZT (piezoelectric transducer) 22 can be any PZT (piezoelectric transducer).In an example explanation, PZT (piezoelectric transducer) 22 is pyroelectric detectors of measuring changes in far infrared radiation by " piezoelectric effect ", described piezoelectric effect causes charge migration under the situation that mechanical strain exists, the variations in temperature that described mechanical strain can be caused by for example far infrared radiation and bringing out.PZT (piezoelectric transducer) 22 can be taked the form of capacitor, i.e. two conductive plates that separate by dielectric, and dielectric can be a piezoelectric ceramic.When the pottery of PZT (piezoelectric transducer) 22 stood mechanical strain, electric charge was moved to another plate from a plate.
In circuit 24 as shown in Figure 2, transducer 22 is connected between the source electrode and grid of junction field effect transistor (FET) Q1, and in non-limiting example, this junction field effect transistor can be realized by the FET of model 2N4338.The drain electrode of FET Q1 shown in power supply 26 is connected to, described power supply can be five volts of power supplys setting up by one or more dry cell batteries.
As shown in Figure 2, be changed to voltage by source current transmission through output resistor R1 with FET Q1.This voltage is connected via mutual conductance resistor R 2 and causes that electric current flows back to the grid of FET Q1, wherein resistor R 1, R2 are connected to ground connection, not transducer 22 " floating " (that is, its signal criterion voltage is not connected to ground connection) between the source electrode and grid of FET Q1 at that time.
Utilize said structure, those skilled in the art will recognize that, FET Q1 controls the feedback current that arrives the grid of FET Q1 through mutual conductance resistor R 2 by the voltage that changes output resistor R1 two ends, and the voltage at described resistor R 1 two ends applies the voltage of identical change between mutual conductance resistor R 2 via the ground connection node.At interchange (AC) component of output resistor R1 two ends measuring circuit 24 output, it can be mechanically multiplies each other by the resistance with the output current of transducer 22 and mutual conductance resistor R 2 with enough precision and calculates, to react the circuit function of reality.The direct current of described output (DC) component is determined by the gate-to-source operating voltage of FET Q1.
In other words, with the non-transconductance circuit contrast of tradition, the common ground of the relative circuit of signal voltage datum node of circuit 24 and floating, in the non-transconductance circuit of tradition, signal voltage datum node ground connection and FET are used as the buffer with the piezoelectric detector of voltage output mode work.Therefore, compare with the conventional voltage Qatput mode circuit, this combination results of transconductance circuit structure the bigger signal voltage of characteristic, and advantageously relatively cheap FET Q1 is used in permission, the type of using in described FETQ1 and the conventional voltage Qatput mode circuit is identical, to substitute more expensive high input impedance operational amplifier relatively.It seems that in another way with the contrast of conventional voltage Qatput mode circuit, the circuit 24 shown in Fig. 2 has three functional blocks in fact, promptly be, transducer 22, FET Q1 and mutual conductance resistor R 2, wherein the latter is a feedback element.
Fig. 3-5 shows the various circuit that added parts to the circuit of Fig. 2, is used to increase the further signal that is produced by circuit.As shown in Figure 3, PZT (piezoelectric transducer) 28 is provided in the transconductance circuit 30 with dc voltage source 32.In circuit 30 as shown in Figure 3, transducer 28 is connected between the source electrode and grid of junction field effect transistor (FET) Q1, and therefore the signal voltage benchmark of circuit 30 floats with respect to the circuit common ground.Power supply 32 is connected to the drain electrode of FET Q1 by drain resistance device R9.
In the circuit shown in Fig. 3, except the other circuit element of discussing below, not only provide FET Q1, bipolar junction transistor (BJT) Q2 also is provided.If wish that cheap standard input impedance operational amplifier can be used to replace BJT Q2." standard input impedance " is meant and is no more than 10
7The impedance of ohm.
In the embodiment shown in Fig. 3, the base stage of BJT Q2 be connected to transducer 28 and be connected to shown in the source electrode of FET Q1, wherein the emitter of BJT Q2 is connected to the output resistor R1 of ground connection and the collector electrode of BJT Q2 is connected to power supply 32, and separates with the drain electrode of FET Q1 by drain resistance device R9.Because the additional gain that provides by BJT Q2 and because its base stage is connected to the source electrode of FETQ1, the output feedback loop divider of being set up by resistor R 3, R4 and capacitor C3 can be added, so that for example 10 times of the basic mutual conductance voltage amplifications that will produce, and this voltage is fed back to the grid of FET Q1 by mutual conductance resistor R 2 as electric current at mutual conductance resistor R 2 two ends.Therefore, the AC component of circuit 30 outputs (measuring at output resistor R1 two ends) can be ten times that the circuit 24 shown in Fig. 2 is exported among Fig. 3, and prerequisite is to provide identical excitation energy to two circuit transducers.
In addition, in the circuit shown in Fig. 3 30, the drain electrode of FET Q1 is in fact by shorted condenser C
5By the source electrode of short circuit (being the AC signal) to FET Q1, as previously mentioned, the source electrode of FET Q1 is the signal voltage datum node.The drain electrode of FET Q1 short circuit in fact is connected to the signal voltage datum node, and the internal capacitance of FET Q1 is no longer set up the feedback element of not expecting, thus the high frequency response of expanded circuit 30.
With reference now to Fig. 4,, PZT (piezoelectric transducer) 34 is provided in the transconductance circuit 36 with dc voltage source 38.In circuit 36 as shown in Figure 4, transducer 34 is connected between the source electrode and grid of junction field effect transistor (FET) Q1, and therefore the signal voltage benchmark of circuit 36 floats with respect to the circuit common ground.As directed, power supply 38 is connected to the drain electrode of FET Q1.
In the embodiment shown in Fig. 4, cheap standard input impedance operational amplifier U1 has its paraphase that is connected with the source electrode of transducer 34 and FET Q1 input, and the source electrode of FET Q1 is connected to ground connection (promptly by resistor R 4) indirectly.The output of operational amplifier U1 is fed back to the grid of FET Q1 by mutual conductance resistor R 3.And the noninvert input of operational amplifier U1 is connected to voltage divider, and this voltage divider is made of the resistor R 2 of resistor R 1 that is connected with power supply 38 and ground connection.
The such situation of circuit as described above is fed grid to FET Q1 from the voltage at the FET source resistance device R2 two ends that source current produces as electric current.The feedback path expansion is by the operational amplifier U1 in the circuit 36 as shown in Figure 4 and by mutual conductance resistor R 3.Mutual conductance electric current summing junction is positioned at the grid of FET Q1, the paraphase input of its buffering operational amplifier U1.The noninvert input of operational amplifier U1 is " floating " signal voltage datum node of circuit 36.Operational amplifier U1 changes its out-put supply with the feedback current of control through mutual conductance resistor R 3, and wherein the output signal of circuit is the AC component of the output voltage of operational amplifier U1, and the DC component is determined by the gate-to-source operating voltage of FET Q1.
Fig. 5 is illustrated in the PZT (piezoelectric transducer) 40 in the transconductance circuit 42 with dc voltage source 44, except resistor R 5 and capacitor C3 being provided between input of the noninvert of operational amplifier U1 and the feedback resistor R3, providing the mutual conductance resistance R 6 between the grid of right tap of resistor R 5/ capacitor C3 and FET Q1, it is all identical with the circuit 36 shown in Fig. 4 in fact in all respects.By the sufficient gain that operational amplifier U1 provides, can be by the output voltage divider of resistor R 3 and R5 and capacitor C3 foundation with for example ten times of basic mutual conductance voltage amplifications.
Fig. 6-9 corresponds respectively to Fig. 2-5, circuit separately is as directed in fact identical, except the variation shown in Fig. 6-9, wherein be connected with DC and be separated from each other to the AC of transducer, to avoid this high DC output that circuit is entered being called the condition of " saturated ", under this condition, circuit DC output voltage should (position of calculating from ideal) than the anode tap corrigendum of power supply or more negative than the cathode terminal of power supply.Because this is impossible actually, circuit DC output may become " being stuck " for the anode tap of power supply or cathode terminal, in this case, the AC signal can not be arranged, otherwise circuit can not be worked fully.This high DC output can be derived from because the caused DC of the bleeder resistance in parallel that exists in some transducers amplifies.When correct work, the circuit as shown in Fig. 6-9 comes work as their separately counterparts in Fig. 2-5, because the signal of AC just of Shi Yonging in the present invention, rather than the DC signal.
Capacitor C by the AC component transmission of transducer output signal is blocked by DC-through AC-in Fig. 6 and 8
Ac, from here again to signal processing circuit, i.e. FET Q1 among Fig. 6 and the operational amplifier U1 among Fig. 8, simultaneously with the DC component of transducer output signal by DC grounding resistor R
DCAnd be diverted to ground connection, finish the above-mentioned AC that from DC, separates.On the other hand in Fig. 7 and 9, recognize capacitor C3 that AC-blocks by DC-Already in these circuit, the output of respective transducer is connected to the circuit between capacitor C3 and the resistor (R4 among Fig. 7, R5 among Fig. 9) in these circuit.
Figure 10 illustrates and the similar circuit of circuit shown in Fig. 9, and wherein similarly invoking marks is represented similar portions, but wherein operational amplifier U1 is replaced by the PNP transistor Q3 with NPN transistor Q4 cascade, to reach more cheap realization.More specifically, in Figure 10, mutual conductance resistance R 6 is connected to the grid of FET Q1, its drain electrode is connected to power line 46, and its source electrode is connected to the bleeder circuit that comprises resistor R 1 and R2 by the output line 48 of having placed PNP transistor Q3 therein, and the work for FET Q1 provides bias voltage signal to these resistance by the source voltage of setting up FET Q1.PNP transistor Q3 cushions this offset signal to set up the source electrode bias voltage of FET Q1.And it is as directed, transistor Q3 is with FET drain electrode-be delivered to the base stage of NPN transistor Q4 to-source electrode output current, wherein, because the gain of transistor Q4, the more megacryst pipe output current (collector-emitter current) that generation matches, itself then be converted back to by the load resistance that is connected with supply voltage and be voltage.
To offer mutual conductance resistor R 6 from the feedback signal of FETQ1 source electrode by feedback line 50 as before, and as mentioned above, in the particular electrical circuit shown in Figure 10, it provides by PNP transistor Q3 and NPN transistor Q4 and feedback resistor R3.According to respect to Fig. 5 and 9 aforesaid principles, PZT (piezoelectric transducer) is connected to capacitor C3 (in the voltage divider part of circuit) via transducer circuit 52, and its AC that is provided to the signal voltage datum node connects.
Above all circuit comprise PZT (piezoelectric transducer) and the mutual conductance resistor that is connected in parallel in the FET grid, the drain electrode of FET is connected to the feedback fraction that power supply and source electrode are connected to circuit.Figure 11 shows can provide PZT (piezoelectric transducer), FET and mutual conductance resistor for convenience in individual packaging, on this packing, provide such as, but not limited to four connectors that are pin, so that transducer, FET source electrode, FET grid and mutual conductance resistor are connected to foregoing circuit.Other connector construction, for example electric wire of socket, pad, welding or the like can use, as long as these connectors can be from the external reference of shell.
Thus, Figure 11 shows packaging structure, and usually by 54 expressions, it comprises shell 55 empty, parallelepiped-shaped, and this shell comprises four aerial lugs 56,58,60,62, and being such as but not limited to is pin.Empty shell 55 has held described PZT (piezoelectric transducer), FET and the mutual conductance resistor in any circuit as implied above.Thus, first and second connectors 56 and 58 can be electrically connected to the FET in the shell 55.More specifically, first connector 56 can be connected to the drain electrode of FET, and is utilized as the circuit as shown in Figure 10 of explanation, and first connector 56 can externally be connected to circuit 46 by the connector of complementary shape, thereby the FET drain electrode is connected to power supply.On the other hand, the 2nd FET connector 58 connects the FET source electrode in the shells 55, and it can engage then be connected to the connector of the complementary shape of circuit 48 among Figure 10, thus the circuit part shown in the FET source electrode is connected to.
The 3rd connector 60 can internally be connected to the mutual conductance resistor.The 3rd connector 60 can be followed externally and engage with the connector of complementary shape, thereby the circuit among Figure 10 50 is connected to mutual conductance resistor R 6 in the shell 55.The 4th connector 62 can be connected to the PZT (piezoelectric transducer) that is included in packaging structure 54 inboards.The 4th connector 62 can then be connected to circuit 52, and as shown in the explanation circuit of Figure 10, circuit 52 connects another circuit structure with the PZT (piezoelectric transducer) at FET grid place.Preferably, three parts of empty outer cover packaging structure 54, promptly PZT (piezoelectric transducer), FET and mutual conductance resistor are packaged in the pure nitrogen gas 64.Be appreciated that physical connector as shown in Figure 10 arranges it only is example, and can realize other connector layout (for example, a connector being arranged on each side of shell 55 4 sides).
The packing of four connectors, three parts above utilizing is included in the inboard of shell 55 with very high resistance (such as 125G ohm mutual conductance resistance normally) the minimum electric current that is associated.The transducer of circuit outside, FET and mutual conductance resistor use than the high a lot of electric current of the electric current that flows through inside the shell.Therefore, when making single shell and be used for comprising as shown in Figure 10 entire circuit, this shell is very expensive, and simple four pins packing as shown in Figure 11 is cheap, and it can be made into just suitable size and holds aforesaid three parts.
On shell and be electrically connected to respectively in the enclosure drain electrode, source electrode, mutual conductance resistor (R2, R3, R6) and PZT (piezoelectric transducer) (22,28,34,40) first to the 4th electric connector (56,58,60,62), described connector mechanically can be coupled with the circuit element outside the shell (55).
Claims (17)
1. piezoelectric detector comprises:
Comprise PZT (piezoelectric transducer) (22,28,34,40) transconductance circuit (24,30,36,42), this transconductance circuit (24,30,36,42) definition common ground and be not directly connected to the signal voltage benchmark of common ground, described transconductance circuit comprises the mutual conductance resistor (R2 of the grid that is connected to field-effect transistor (Q1), R3, R6), described transconductance circuit (24,30,36,42) do not have impedance greater than 10
7The operational amplifier of ohm, described field-effect transistor is also connected to described PZT (piezoelectric transducer).
2. according to the detector of claim 1, wherein (R3 R6) is connected to grid by operational amplifier (U1) to the mutual conductance resistor.
3. according to the detector of claim 2, wherein the paraphase of operational amplifier (U1) input is connected to the source electrode of field-effect transistor (Q1).
4. according to the detector of claim 3, wherein the input of the noninvert of operational amplifier (U1) is connected to the signal voltage benchmark.
5. according to the detector of claim 1, comprise the output resistor (R1) that is connected to field-effect transistor (Q1) source electrode, obtain the output of described circuit at these output resistor two ends.
6. according to the detector of claim 5, wherein output resistor (R1) is connected to field-effect transistor (Q1) by bipolar junction transistor (Q2).
7. according to the detector of claim 6, wherein the base stage of bipolar junction transistor (Q2) is connected to the source electrode of field-effect transistor (Q1).
8. according to the detector of claim 1, comprise the shorted condenser (C that the drain electrode of field-effect transistor (Q1) is connected to field-effect transistor (Q1) source electrode
3).
9. according to the detector of claim 1, comprise output voltage divider between the source electrode of the grid that is connected field-effect transistor (Q1) and field-effect transistor (Q1) (R3, R4, C3 and R3, R5, C3).
10. one kind comprises PZT (piezoelectric transducer) (22,28,34,40) mutual conductance detector circuit, wherein field-effect transistor (Q1) is connected to the described transducer (22,28,34 that is used to amplify transducer signal, 40), circuit common ground and signal voltage datum node, this node is in any AC current potential except that ground connection.
11. mutual conductance detector circuit according to claim 10, comprise the mutual conductance resistor (R2 that is connected to field-effect transistor (Q1) grid, R3, R6), the mutual conductance detector circuit does not have high input impedance operational amplifier, described field-effect transistor is also connected to described PZT (piezoelectric transducer), and described high impedance is the impedance of at least 10 megohms.
12. a circuit comprises:
PZT (piezoelectric transducer) (22,28,34,40);
Transconductance circuit (24,30,36,42), it receives from transducer (22 along electric pathway, 28,34,40) signal, and handle this signal to produce output, this transconductance circuit (24,30,36,42) do not comprise high input impedance operational amplifier, described high impedance is the impedance of at least 10 megohms.
13. a piezoelectric detector comprises:
The transconductance circuit that comprises PZT (piezoelectric transducer), described PZT (piezoelectric transducer) is connected to the grid of the field-effect transistor (Q1) of transconductance circuit, this transconductance circuit does not have operational amplifier, this transconductance circuit also comprises the mutual conductance resistor (R6) that is connected to field-effect transistor (Q1) grid, this circuit comprises the first transistor (Q3) and the transistor seconds (Q4) except this field-effect transistor (Q1), and field-effect transistor (Q1), the first transistor (Q3) and transistor seconds (Q4) are electrically connected to each other.
14. according to the detector of claim 13, comprise the feedback circuit part that is connected to field-effect transistor (Q1) source electrode (50, R3).
15. according to the detector of claim 14, wherein transistor seconds (Q4) is electrically connected to mutual conductance resistor (R6) and the first transistor (Q3).
16. detector according to claim 13, comprise and physically only hold PZT (piezoelectric transducer), field-effect transistor (Q1), with the transducer of mutual conductance resistor (R6) packing (54), this transducer comprises and is used for being connected with power supply and is electrically connected to first connector (56) of the accessible outside that field-effect transistor (Q1) drains, be electrically connected to second connector (58) of the accessible outside of field-effect transistor (Q1) source electrode, be electrically connected to the 3rd connector (60) of the accessible outside of mutual conductance resistor (R6), the 4th connector (62) with the accessible outside that is electrically connected to PZT (piezoelectric transducer).
17. a piezoelectric detector packing (54) comprising:
Shell (55);
PZT (piezoelectric transducer) in shell (22,28,34,40);
Field-effect transistor in shell (Q1), this field-effect transistor (Q1) definition and transducer (22,28,34,40) grid of Lian Jieing, the grid of this field effect transistor are also connected to mutual conductance resistor (R2, R3, R6), this field-effect transistor (Q1) also defines source electrode and drain electrode;
First connector to the, four connectors (56,58,60 on shell, 62), these first connector to the, four connectors (56,58,60,62) be electrically connected to respectively in the enclosure drain electrode, source electrode, mutual conductance resistor (R2, R3, R6) and PZT (piezoelectric transducer) (22,28,34,40), described four connectors mechanically are coupled with shell (55) circuit element outward.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US10/812,603 | 2004-03-30 | ||
| US10/812,603 US7042134B2 (en) | 2003-03-31 | 2004-03-30 | Transconductance circuit for piezoelectric transducer |
| PCT/US2005/008726 WO2005101538A2 (en) | 2003-03-31 | 2005-03-16 | Transconductance circuit for piezoelectric transducer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1969401A CN1969401A (en) | 2007-05-23 |
| CN1969401B true CN1969401B (en) | 2010-06-09 |
Family
ID=38077170
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2005800108689A Expired - Fee Related CN1969401B (en) | 2004-03-30 | 2005-03-16 | Transconductance circuit for piezoelectric transducer, Piezoelectric detector and its package |
Country Status (3)
| Country | Link |
|---|---|
| CN (1) | CN1969401B (en) |
| BR (1) | BRPI0509551A (en) |
| RU (1) | RU2390882C2 (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1159659A (en) * | 1995-08-31 | 1997-09-17 | 株式会社村田制作所 | Piezoelectric transducer |
| CN1299530A (en) * | 1998-04-29 | 2001-06-13 | 爱特梅尔股份有限公司 | Crystal osciallator with controlled duty cycle |
| US6647764B1 (en) * | 1998-10-26 | 2003-11-18 | Frank Paul | Quartz crystal microbalance with feedback loop for automatic gain control |
-
2005
- 2005-03-16 BR BRPI0509551-4A patent/BRPI0509551A/en not_active Application Discontinuation
- 2005-03-16 CN CN2005800108689A patent/CN1969401B/en not_active Expired - Fee Related
- 2005-03-16 RU RU2006135801/28A patent/RU2390882C2/en active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1159659A (en) * | 1995-08-31 | 1997-09-17 | 株式会社村田制作所 | Piezoelectric transducer |
| CN1299530A (en) * | 1998-04-29 | 2001-06-13 | 爱特梅尔股份有限公司 | Crystal osciallator with controlled duty cycle |
| US6647764B1 (en) * | 1998-10-26 | 2003-11-18 | Frank Paul | Quartz crystal microbalance with feedback loop for automatic gain control |
Also Published As
| Publication number | Publication date |
|---|---|
| BRPI0509551A (en) | 2007-09-18 |
| CN1969401A (en) | 2007-05-23 |
| RU2390882C2 (en) | 2010-05-27 |
| RU2006135801A (en) | 2008-04-20 |
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| C14 | Grant of patent or utility model | ||
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| CF01 | Termination of patent right due to non-payment of annual fee |
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