JPH06180336A - Capacitance type physical quantity detecting device - Google Patents
Capacitance type physical quantity detecting deviceInfo
- Publication number
- JPH06180336A JPH06180336A JP35358592A JP35358592A JPH06180336A JP H06180336 A JPH06180336 A JP H06180336A JP 35358592 A JP35358592 A JP 35358592A JP 35358592 A JP35358592 A JP 35358592A JP H06180336 A JPH06180336 A JP H06180336A
- Authority
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- Japan
- Prior art keywords
- circuit
- capacitance
- input terminal
- operational amplifier
- physical quantity
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- Measuring Fluid Pressure (AREA)
- Transmission And Conversion Of Sensor Element Output (AREA)
- Measurement Of Resistance Or Impedance (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、静電容量型の物理量測
定装置に関し、特に、微細加工にも対応できるセンサの
回路構造に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capacitance type physical quantity measuring device, and more particularly to a circuit structure of a sensor which can be used for fine processing.
【０００２】[0002]
【従来の技術】従来、半導体基板にギャップ及びダイヤ
フラムを微細加工して、ギャップ間隔が、印加される物
理量によって変化することを利用した静電容量型物理量
測定装置が知られている。この装置は、ギャップ間隔が
静電容量に反比例することから、静電容量の変化を電気
信号に変換して物理量を検出するものである。2. Description of the Related Art Heretofore, there has been known an electrostatic capacitance type physical quantity measuring apparatus which utilizes the fact that a gap and a diaphragm are finely processed on a semiconductor substrate and the gap distance changes depending on the applied physical quantity. Since the gap interval is inversely proportional to the capacitance, this device converts a change in capacitance into an electric signal to detect a physical quantity.
【０００３】[0003]
【発明が解決しようとする課題】しかしながら、容量に
電圧を印加して、容量変化を検出することから、容量セ
ンサを半導体の微細加工で形成するような場合には、印
加電圧によりギャップに体面する電極が静電引力により
接触するという問題がある。However, since a voltage is applied to the capacitance to detect the capacitance change, when the capacitance sensor is formed by fine processing of the semiconductor, the applied voltage causes the gap to face the body. There is a problem that the electrodes come into contact with each other by electrostatic attraction.
【０００４】本発明は上記の課題を解決するために成さ
れたものであり、その目的は、静電引力により対抗する
電極が接触しないように、低電圧で駆動可能とすること
である。The present invention has been made to solve the above problems, and an object thereof is to enable driving at a low voltage so that electrodes facing each other do not come into contact with each other due to electrostatic attraction.
【０００５】[0005]
【０００６】本発明の構成は、演算増幅器を用いて容量
センサの容量変化を検出するようにしたものであり、容
量センサの演算増幅に対する接続に特徴がある。請求項
１記載の発明は、演算増幅器を逆相増幅器として用いた
ものであり、第１の演算増幅器と、入力端子と演算増幅
器の反転入力端子の間に接続された第１の抵抗と、演算
増幅器の反転入力端子と出力端子の間に接続された第２
の抵抗と、入力端子と演算増幅器の非反転入力端子との
間に接続された容量センサと、演算増幅器の非反転入力
端子と共通端子との間に接続された第１のスイッチ手段
とを備え、演算増幅器の出力を出力端子に接続したこと
を特徴とする。The configuration of the present invention is to detect the capacitance change of the capacitance sensor by using the operational amplifier, and is characterized by the connection of the capacitance sensor to the operational amplification. The invention according to claim 1 uses an operational amplifier as a negative phase amplifier, and includes a first operational amplifier, a first resistor connected between an input terminal and an inverting input terminal of the operational amplifier, and an operational amplifier. A second connected between the inverting input and the output of the amplifier
, A capacitance sensor connected between the input terminal and the non-inverting input terminal of the operational amplifier, and a first switch means connected between the non-inverting input terminal of the operational amplifier and the common terminal. The output of the operational amplifier is connected to the output terminal.
【０００７】又、請求項２記載の発明は、演算増幅器を
正相増幅器として動作するように、容量センサを演算増
幅の非反転入力端子に、スイッチ手段により初期充電
と、放置とが可能なように接続したものである。According to the second aspect of the present invention, the capacitance sensor is used as the non-inverting input terminal of the operational amplification so that the operational amplifier operates as a positive phase amplifier, and the switch means enables the initial charging and the leaving. Connected to.
【０００８】又、請求項３記載の発明は、上記回路Ｘ
と、回路Ｘにおいて容量センサの代わりに固定容量とし
た回路Ｙとを用いて、回路Ｘと回路Ｙとを入力側で並列
接続し、出力側を差動増幅器に接続したことを特徴とす
る。The invention according to claim 3 is the circuit X described above.
And a circuit Y having a fixed capacitance in place of the capacitance sensor in the circuit X, the circuit X and the circuit Y are connected in parallel on the input side, and the output side is connected to the differential amplifier.
【０００９】又、請求項４記載の発明は、上記の回路Ｘ
と回路Ｙとを入力側で並列接続し、回路Ｙの出力側にそ
の出力電圧のレベルを判定し、そのレベルが所定レベル
より低下した時に、回路Ｘと回路Ｙのスイッチ手段を容
量センサ及び固定容量を充電する側に切り換える制御回
路を設けたことである。According to a fourth aspect of the invention, there is provided the above circuit X.
And the circuit Y are connected in parallel on the input side, the level of the output voltage is judged on the output side of the circuit Y, and when the level falls below a predetermined level, the switch means of the circuit X and the circuit Y are fixed to the capacitance sensor and fixed. That is, the control circuit for switching the capacity to the charging side is provided.
【００１０】又、請求項５記載の発明は、請求項３記載
の発明に、さらに、回路Ｙの出力側にその出力電圧のレ
ベルを判定し、そのレベルが所定レベルより低下した時
に、回路Ｘと回路Ｙのスイッチ手段を容量センサ及び固
定容量を充電する側に切り換える制御回路を設けたこと
である。According to a fifth aspect of the present invention, in addition to the third aspect of the invention, the level of the output voltage of the circuit Y is judged on the output side, and when the level drops below a predetermined level, the circuit X And a control circuit for switching the switching means of the circuit Y to the side for charging the capacitance sensor and the fixed capacitance.
【００１１】[0011]
【作用及び発明の効果】スイッチ手段により、容量セン
サは初期電圧に充電され、測定時に、演算増幅器の非反
転入力端子に接続される。この時、容量センサに充電さ
れた電荷は、演算増幅器の非反転入力端子に接続されて
いることから、電荷は放電されない。そして、物理量が
容量センサに印加されると、容量センサの静電容量が変
化し、容量センサの端子間電圧が変化する。この電圧変
化分が、演算増幅器の反転入力端子に接続された第１の
抵抗と、反転入力端子と出力端子間に接続された第２の
抵抗とで決定される増幅率で増幅される。よって、容量
センサには大きな電圧を印加する必要がないので、容量
センサの対抗する電極が静電力により接触することが防
止される。By the switch means, the capacitance sensor is charged to the initial voltage and connected to the non-inverting input terminal of the operational amplifier during measurement. At this time, since the electric charge charged in the capacitance sensor is connected to the non-inverting input terminal of the operational amplifier, the electric charge is not discharged. When a physical quantity is applied to the capacitance sensor, the capacitance of the capacitance sensor changes and the voltage across the terminals of the capacitance sensor changes. This voltage change is amplified with an amplification factor determined by the first resistance connected to the inverting input terminal of the operational amplifier and the second resistance connected between the inverting input terminal and the output terminal. Therefore, since it is not necessary to apply a large voltage to the capacitance sensor, the opposing electrodes of the capacitance sensor are prevented from coming into contact with each other due to electrostatic force.
【００１２】請求項３記載の発明では、上述した作用効
果の他に、差動増幅器を用いていることから、容量セン
サの容量変化量が、その時の信号のレベルとして現れる
ため、測定が容易となる。又、請求項４記載の発明で
は、容量センサに蓄積された電荷が放電して減少した場
合には、制御回路の作動により、スイッチ手段が容量セ
ンサ及び固定容量を充電する方向に切り換えられ、初期
充電が自動的に行われるので、使用性が向上する。According to the third aspect of the invention, in addition to the above-mentioned effects, since the differential amplifier is used, the capacitance change amount of the capacitance sensor appears as the signal level at that time, which facilitates the measurement. Become. Further, in the invention described in claim 4, when the electric charge accumulated in the capacitance sensor is discharged and reduced, the switch circuit is switched to the direction in which the capacitance sensor and the fixed capacitance are charged by the operation of the control circuit. Since charging is done automatically, usability is improved.
【００１３】又、請求項５記載の発明では、請求項３記
載の発明と請求項４記載の発明とを併せた構造であるた
め、信号レベルの直読ができ、容量センサの初期充電が
自動的に行われるために使用性が良い。Further, according to the invention of claim 5, since the structure of the invention of claim 3 and the invention of claim 4 are combined, the signal level can be directly read and the initial charging of the capacitance sensor is automatically performed. Usability is good because it is performed in
【００１４】[0014]
【実施例】以下、本発明を具体的な実施例に基づいて説
明する。 第１実施例 図１において、１は入力端子、２は共通端子、３は出力
端子、８は演算増幅器である。入力端子１と演算増幅器
８の反転入力端子との間に第１の抵抗４が接続されてお
り、反転入力端子と出力端子３との間に第２の抵抗５が
接続されている。又、入力端子１と演算増幅器８の非反
転入力端子との間に容量センサ６が接続されており、非
反転入力端子と共通端子２との間にスイッチ７が接続さ
れている。この装置は、入力端子１と共通端子２との間
に電圧Ｖinが印加され、出力端子３と共通端子２との間
の電圧Ｖout を出力信号として出力する装置である。EXAMPLES The present invention will be described below based on specific examples. First Embodiment In FIG. 1, 1 is an input terminal, 2 is a common terminal, 3 is an output terminal, and 8 is an operational amplifier. The first resistor 4 is connected between the input terminal 1 and the inverting input terminal of the operational amplifier 8, and the second resistor 5 is connected between the inverting input terminal and the output terminal 3. A capacitance sensor 6 is connected between the input terminal 1 and the non-inverting input terminal of the operational amplifier 8, and a switch 7 is connected between the non-inverting input terminal and the common terminal 2. This device is a device in which a voltage Vin is applied between the input terminal 1 and the common terminal 2 and the voltage Vout between the output terminal 3 and the common terminal 2 is output as an output signal.
【００１５】この容量センサ６は良く知られた半導体容
量センサとして構成することができる。即ち、半導体基
板に微小ギャップを隔てたダイヤフラムと、微小ギャッ
プの対抗面に電極を形成し、測定する物理量が圧力の場
合に、この圧力をダイヤフラムに印加し、容量の変化で
圧力を測定することができる。又、演算増幅器８も同一
の半導体基板上に形成することもできる。The capacitance sensor 6 can be constructed as a well-known semiconductor capacitance sensor. That is, when a diaphragm with a minute gap is formed on a semiconductor substrate and an electrode is formed on the opposing surface of the minute gap and the physical quantity to be measured is pressure, this pressure is applied to the diaphragm and the pressure is measured by the change in capacitance. You can Further, the operational amplifier 8 can also be formed on the same semiconductor substrate.
【００１６】次に、本装置の動作について説明する。入
力端子１と共通端子２の間には適当な定電圧Ｖinが印加
され、共通端子２は接地されている。動作は充電期間と
動作期間に分けられる。この装置では、充電期間は基準
となる物理量が容量センサに印加されている。例えば、
加速度センサでは、基準加速度（零を含む）が印加さ
れ、圧力センサでは基準圧力（大気圧、零圧力を含む）
が印加されている。そして、スイッチ７がオフされた動
作期間の任意時刻において、測定すべき物理量が容量セ
ンサに印加される。そして、その物理量の印加後の出力
信号から物理量が測定される。Next, the operation of this apparatus will be described. An appropriate constant voltage Vin is applied between the input terminal 1 and the common terminal 2, and the common terminal 2 is grounded. The operation is divided into a charging period and an operating period. In this device, a reference physical quantity is applied to the capacitance sensor during the charging period. For example,
Reference acceleration (including zero) is applied to the acceleration sensor, and reference pressure (including atmospheric pressure and zero pressure) is applied to the pressure sensor.
Is being applied. Then, at an arbitrary time during the operation period when the switch 7 is turned off, the physical quantity to be measured is applied to the capacitance sensor. Then, the physical quantity is measured from the output signal after the application of the physical quantity.
【００１７】充電期間では、スイッチ７が閉じられ、容
量センサ６の一方の端子が接地されるので、容量センサ
６は電圧Ｖinにより充電される。この時、出力端子３の
電圧Ｖout は、During the charging period, the switch 7 is closed and one terminal of the capacitance sensor 6 is grounded, so that the capacitance sensor 6 is charged by the voltage Vin. At this time, the voltage Vout of the output terminal 3 is
【００１８】[0018]
【数１】Ｖout ＝−Ｖin・Ｒ２／Ｒ１ となる。## EQU1 ## Vout = -Vin.R2 / R1.
【００１９】また、この時の容量センサ６の静電容量を
Ｃ、容量センサ６に蓄えられた電荷量をＱとするとFurther, assuming that the capacitance of the capacitance sensor 6 at this time is C and the amount of charge accumulated in the capacitance sensor 6 is Q.
【数２】Ｑ＝Ｃ・Ｖin となる。## EQU2 ## Q = C.Vin.
【００２０】動作期間ではスイッチ７が開かれる。この
状態で物理量が変化しセンサの容量値がＣ１になったと
すると、電荷量Ｑは変化しないため容量センサ６の両端
にかかる電圧が変化し、その値をＶ１とすると、During the operation period, the switch 7 is opened. If the physical quantity changes in this state and the capacitance value of the sensor becomes C1, the charge quantity Q does not change, so the voltage applied across the capacitance sensor 6 changes, and if that value is V1, then
【数３】Ｑ＝Ｃ１・Ｖ１ となる。数２、数３より、(3) Q = C1 · V1. From equations 2 and 3,
【数４】Ｖ１＝Ｖin・Ｃ／Ｃ１ となり、容量の変化に反比例することがわかる。また、
この時の出力電圧をＶout1とすると[Equation 4] V1 = Vin · C / C1 and it can be seen that it is inversely proportional to the change in capacitance. Also,
If the output voltage at this time is Vout1,
【数５】Ｖout1＝Ｖin−Ｖ１−（Ｒ２／Ｒ１）・Ｖ１＝
｛１−〔１＋（Ｒ２／Ｒ１）〕・（Ｃ／Ｃ１）｝・Ｖin 物理量が変化する前後の出力電位差は、数１、数５よ
り、[Formula 5] Vout1 = Vin−V1- (R2 / R1) · V1 =
{1- [1+ (R2 / R1)] · (C / C1)} · Vin The output potential difference before and after the physical quantity changes is given by
【数６】Ｖout1−Ｖout ＝〔１＋（Ｒ２／Ｒ１）〕・
〔１−Ｃ／Ｃ１〕・Ｖin[Equation 6] Vout1−Vout = [1+ (R2 / R1)] ・
[1-C / C1] ・ Vin
【００２１】容量の変化量（Ｃ１−Ｃ）をΔＣ、出力電
圧の変化量（Ｖout1−Ｖout)をΔVとすると、When the change amount of capacitance (C1-C) is ΔC and the change amount of output voltage (Vout1-Vout) is ΔV,
【数７】Ｃ１＝Ｃ＋ΔＣ[Formula 7] C1 = C + ΔC
【数８】Ｖout1−Ｖout ＝ΔＶ 数７、数８を数６に代入して、[Equation 8] Vout1−Vout = ΔV Equations 7 and 8 are substituted into Equation 6 to obtain
【数９】ΔＶ＝〔１＋（Ｒ２／Ｒ１）〕・（ΔＣ／Ｃ
１）・Ｖin＝Ｇ・（ΔＣ／Ｃ１）・Ｖin となる。ΔＶは入力電圧Ｖinと増幅率Ｇ＝１＋（Ｒ２／
Ｒ１）の値を適当に選択することで、ΔＣ／Ｃ１を任意
に増幅できる。[Formula 9] ΔV = [1+ (R2 / R1)] · (ΔC / C
1) · Vin = G · (ΔC / C1) · Vin. ΔV is the input voltage Vin and the amplification factor G = 1 + (R2 /
By properly selecting the value of R1), ΔC / C1 can be arbitrarily amplified.
【００２２】このように、Ｇを大きくすれば小さい電圧
Ｖinで済むので、容量センサを小型にした場合に、静電
力による電極の接触を防止することができる。よって、
高密度で集積した容量型物理量測定装置を製造すること
が可能となる。また、充電時に蓄えられた電荷量が変化
しなければ、電源投入時に充電するのみで良いことや、
充電時以外はスイッチ７は開閉動作をしないため低ノイ
ズという特徴も有する。In this way, if G is increased, a small voltage Vin is sufficient, so that when the capacitance sensor is downsized, it is possible to prevent the electrodes from coming into contact with each other due to electrostatic force. Therefore,
It is possible to manufacture a capacitance type physical quantity measuring device integrated at high density. Also, if the amount of charge stored at the time of charging does not change, it is only necessary to charge when the power is turned on,
Since the switch 7 does not open and close except during charging, it has a feature of low noise.
【００２３】第２実施例 本実施例は、第１実施例と異なり、正相増幅器として構
成した点が異なる。共通端子２と演算増幅器８の反転入
力端子との間に第１の抵抗４が接続されており、演算増
幅器８の反転入力端子と出力端子３との間に第２の抵抗
５が接続されている。そして、入力端子１と共通端子２
との間にスイッチ７を介して、容量センサ６が配設され
ている。又、スイッチ７は、切替えにより、容量センサ
６の一端を入力端子１に接続し、又は、演算増幅器８の
非反転入力端子に接続する。この装置は、入力端子１と
共通端子２との間に電圧Ｖinが印加され、出力端子３と
共通端子２との間の電圧Ｖout を出力信号として出力す
る装置である。Second Embodiment This embodiment is different from the first embodiment in that it is configured as a positive phase amplifier. The first resistor 4 is connected between the common terminal 2 and the inverting input terminal of the operational amplifier 8, and the second resistor 5 is connected between the inverting input terminal of the operational amplifier 8 and the output terminal 3. There is. Then, the input terminal 1 and the common terminal 2
The capacitance sensor 6 is disposed between the switch and the switch via a switch 7. The switch 7 connects one end of the capacitance sensor 6 to the input terminal 1 or the non-inverting input terminal of the operational amplifier 8 by switching. This device is a device in which a voltage Vin is applied between the input terminal 1 and the common terminal 2 and the voltage Vout between the output terminal 3 and the common terminal 2 is output as an output signal.
【００２４】まず、充電期間において、スイッチ７はａ
端子とｃ端子とを接続する状態となり、容量センサ６に
電圧Ｖinにより充電される。次に、測定期間において、
スイッチ７は端子ｂと端子ｃとを接続する状態となる。
この初期状態におけるＶoutは次式で表される。First, during the charging period, the switch 7 is set to a
The terminal and the c terminal are connected, and the capacitance sensor 6 is charged with the voltage Vin. Next, in the measurement period,
The switch 7 will be in the state which connects the terminal b and the terminal c.
Vout in this initial state is expressed by the following equation.
【００２５】[0025]
【数１０】Ｖout ＝Ｖin（１＋Ｒ２／Ｒ１） 次に、この状態から容量センサ６に物理量が印加され
て、容量センサ６の静電容量がＣからＣ１に変化したと
する。この時の出力Ｖout1は次式で表される。## EQU10 ## Vout = Vin (1 + R2 / R1) Next, assume that a physical quantity is applied to the capacitance sensor 6 from this state and the capacitance of the capacitance sensor 6 changes from C to C1. The output Vout1 at this time is expressed by the following equation.
【数１１】 Ｖout1＝Ｖin（１＋Ｒ２／Ｒ１）（Ｃ／Ｃ１） よって、出力電圧の変化ΔＶは、次式で表現される。Vout1 = Vin (1 + R2 / R1) (C / C1) Therefore, the change ΔV in the output voltage is expressed by the following equation.
【数１２】 ΔＶ＝−Ｖin（１＋Ｒ２／Ｒ１）（ΔＣ／Ｃ１） となる。[Formula 12] ΔV = −Vin (1 + R2 / R1) (ΔC / C1)
【００２６】よって、第１実施例と同様に、利得Ｇ（＝
１＋Ｒ２／Ｒ１）を適切に設定することによって、容量
センサ６に印加する電圧Ｖinを小さくしても、容量の変
化率を増幅して観測することが可能となる。Therefore, as in the first embodiment, the gain G (=
By appropriately setting (1 + R2 / R1), the rate of change in capacitance can be amplified and observed even if the voltage Vin applied to the capacitance sensor 6 is reduced.
【００２７】第３実施例 本実施例は、第１実施例の回路を４端子回路網と見なし
た時、同様な回路Ｘ、Ｙを並列接続したものである。但
し、回路Ｘと回路Ｙとで回路定数は等しく、回路Ｘは物
理量を印加する容量センサ６で構成するが回路Ｙは物理
量により静電容量の変化しない固定容量６' が用いられ
ている。又、出力側は、差動増幅器９により接続し、そ
れぞれの出力ＶoutXとＶoutYとを差動増幅して出力Ｖou
t を得るようにしている。Third Embodiment In this embodiment, when the circuit of the first embodiment is regarded as a four-terminal circuit network, similar circuits X and Y are connected in parallel. However, the circuit X and the circuit Y have the same circuit constant, and the circuit X is composed of the capacitance sensor 6 which applies a physical quantity, but the circuit Y uses a fixed capacitance 6 ′ whose capacitance does not change depending on the physical quantity. Further, the output side is connected by a differential amplifier 9, and the outputs VoutX and VoutY are differentially amplified and output Vou.
trying to get t.
【００２８】このような構成の時、測定時の物理量が印
加された状態で回路Ｘの出力は数５となり、回路Ｙの出
力は容量が変化しないので数１となる。よって、差動増
幅器９の出力Ｖout は、数９となる。このように、本実
施例では、物理量の変化率が出力電圧の信号レベルにそ
のまま反映される。With such a configuration, the output of the circuit X becomes the expression 5 while the physical quantity at the time of measurement is applied, and the output of the circuit Y becomes the expression 1 because the capacitance does not change. Therefore, the output Vout of the differential amplifier 9 is given by Equation 9. As described above, in this embodiment, the rate of change of the physical quantity is directly reflected on the signal level of the output voltage.
【００２９】第４実施例 第１の実施例では、容量センサ６の電荷量がスイッチ７
や演算増幅器８の入力端子のリーク電流により徐徐に減
少する。第４の実施例の回路は、図４に示すように、第
１の実施例の回路Ｘと同様な構成の回路Ｙを入力側での
み並列接続したものである。但し、回路Ｘと回路Ｙとで
回路定数は等しく、回路Ｘは物理量を印加する容量セン
サ６で構成するが回路Ｙは物理量により静電容量の変化
しない固定容量６' が用いられている。そして、回路Ｙ
は演算増幅器８’の出力が所定のレベルまで変化したこ
とを感知してスイッチ７、７’を制御し、電荷量を初期
化する制御回路１０を付加した構造とした。このような
構成とする事により電荷量の変化を感知して自動的に電
荷量の初期化ができる。Fourth Embodiment In the first embodiment, the amount of charge of the capacitance sensor 6 is the switch 7
And the leak current of the input terminal of the operational amplifier 8 gradually decreases. In the circuit of the fourth embodiment, as shown in FIG. 4, a circuit Y having the same configuration as the circuit X of the first embodiment is connected in parallel only on the input side. However, the circuit X and the circuit Y have the same circuit constant, and the circuit X is composed of the capacitance sensor 6 which applies a physical quantity, but the circuit Y uses a fixed capacitance 6 ′ whose capacitance does not change depending on the physical quantity. And circuit Y
Has a structure in which a control circuit 10 which senses that the output of the operational amplifier 8'changes to a predetermined level and controls the switches 7 and 7'to initialize the charge amount is added. With such a configuration, the change in the charge amount can be detected and the charge amount can be automatically initialized.
【００３０】第５実施例 第５実施例は、図３の第３実施例の回路に、図４の第４
実施例の回路のように、容量センサ６と固定容量６' と
を初期状態に充電する制御回路１０を付加したものであ
る。また、第３、第４、第５の実施例のようなスイッチ
の自動制御、差動増幅は第２の実施例にも適用できる。Fifth Embodiment In the fifth embodiment, the circuit of the third embodiment of FIG.
Like the circuit of the embodiment, a control circuit 10 for charging the capacitance sensor 6 and the fixed capacitance 6 ′ to the initial state is added. The automatic switch control and differential amplification as in the third, fourth and fifth embodiments can also be applied to the second embodiment.
【図１】本発明の第１実施例にかかる装置を示した回路
図。FIG. 1 is a circuit diagram showing an apparatus according to a first embodiment of the present invention.
【図２】本発明の第２実施例にかかる装置を示した回路
図。FIG. 2 is a circuit diagram showing an apparatus according to a second embodiment of the present invention.
【図３】本発明の第３実施例にかかる装置を示した回路
図。FIG. 3 is a circuit diagram showing an apparatus according to a third embodiment of the present invention.
【図４】本発明の第４実施例にかかる装置を示した回路
図。FIG. 4 is a circuit diagram showing an apparatus according to a fourth embodiment of the present invention.
【図５】本発明の第５実施例にかかる装置を示した回路
図。FIG. 5 is a circuit diagram showing an apparatus according to a fifth embodiment of the present invention.
１…入力端子 ２…共通端子 ３…出力端子 ４…第１の抵抗 ５…第２の抵抗 ８…演算増幅器 ６…容量センサ ６' …固定容量DESCRIPTION OF SYMBOLS 1 ... Input terminal 2 ... Common terminal 3 ... Output terminal 4 ... 1st resistance 5 ... 2nd resistance 8 ... Operational amplifier 6 ... Capacitance sensor 6 ' ... Fixed capacity
Claims (5)
化させ、静電容量を電気信号に変換することにより、物
理量を検出する静電容量式物理量検出装置において、 第１の演算増幅器と、 入力端子と前記演算増幅器の反転入力端子の間に接続さ
れた第１の抵抗と、 前記演算増幅器の反転入力端子と出力端子の間に接続さ
れた第２の抵抗と、 前記入力端子と前記演算増幅器の非反転入力端子との間
に接続された容量センサと、 前記演算増幅器の非反転入力端子と共通端子との間に接
続された第１のスイッチ手段とを備え、前記演算増幅器
の出力を出力端子に接続したことを特徴とする静電容量
式物理量検出装置。1. An electrostatic capacitance type physical quantity detection device for detecting a physical quantity by changing the electrostatic capacity according to a physical quantity to be detected and converting the electrostatic capacity into an electric signal. A first resistor connected between the input terminal and the inverting input terminal of the operational amplifier, a second resistor connected between the inverting input terminal and the output terminal of the operational amplifier, the input terminal and the An output of the operational amplifier, comprising: a capacitance sensor connected between the operational amplifier and a non-inverting input terminal; and a first switch means connected between the operational amplifier non-inverting input terminal and a common terminal. Is connected to the output terminal of the electrostatic capacity type physical quantity detection device.
化させ、静電容量を電気信号に変換することにより、物
理量を検出する静電容量式物理量検出装置において、 第１の演算増幅器と、 共通端子と前記演算増幅器の反転入力端子の間に接続さ
れた第１の抵抗と、 前記演算増幅器の反転入力端子と出力端子の間に接続さ
れた第２の抵抗と、 一端が前記共通端子に接続された容量センサと、 前記演算増幅器の非反転入力端子と前記入力端子と間に
介在され、切替え動作により、前記入力端子と前記容量
センサの他端とを接続し、又は、前記演算増幅器の非反
転入力端子と前記容量センサの他端とを接続することが
可能なスイッチ手段と、 を備え、前記演算増幅器の出力を出力端子に接続したこ
とを特徴とする静電容量式物理量検出装置。2. A capacitance type physical quantity detection device for detecting a physical quantity by changing the capacitance according to a physical quantity to be detected and converting the capacitance into an electric signal, the first operational amplifier and A first resistor connected between a common terminal and the inverting input terminal of the operational amplifier, a second resistor connected between the inverting input terminal and the output terminal of the operational amplifier, and one end of the common terminal Is interposed between the non-inverting input terminal and the input terminal of the operational amplifier, and connects the input terminal and the other end of the capacitive sensor by a switching operation, or the operational amplifier. And a switch means capable of connecting the other end of the capacitance sensor to the other end of the capacitance sensor, and the output of the operational amplifier is connected to the output terminal. .
器、第１の抵抗、第２の抵抗、容量センサ、スイッチ手
段で構成される回路Ｘにおいて前記容量センサを固定容
量に交換した回路Ｙを設け、回路Ｘと回路Ｙとを入力側
で並列接続し、出力側にそれぞれの出力を差動増幅する
差動増幅器とを設けたことを特徴とする請求項１又は請
求項２に記載の静電容量式物理量検出装置。3. A circuit Y comprising the operational amplifier, the first resistance, the second resistance, the capacitance sensor and the switch means according to claim 1, wherein the capacitance sensor is replaced with a fixed capacitance. 3. The circuit X and the circuit Y are connected in parallel on the input side, and a differential amplifier for differentially amplifying the respective outputs is provided on the output side, according to claim 1 or 2. Capacitance type physical quantity detection device.
器、第１の抵抗、第２の抵抗、容量センサ、スイッチ手
段でされる回路Ｘにおいて前記容量センサを固定容量に
交換した回路Ｙを設け、回路Ｘと回路Ｙとを入力側で並
列接続し、前記回路Ｙの出力に回路Ｙの出力電圧レベル
を検出し、所定レベルより低下した場合に、前記回路Ｘ
及び前記回路Ｙのスイッチ手段を前記容量センサを充電
する側に切り換える制御回路を設けたことを特徴とする
請求項１又は請求項２に記載の静電容量式物理量検出装
置。4. A circuit Y comprising the operational amplifier, the first resistance, the second resistance, the capacitance sensor, and the switch means, wherein the capacitance sensor is replaced with a fixed capacitance in the circuit X according to claim 1 or 2. The circuit X and the circuit Y are connected in parallel on the input side, the output voltage level of the circuit Y is detected at the output of the circuit Y, and the circuit X is detected when the output voltage level falls below a predetermined level.
3. A capacitance type physical quantity detection device according to claim 1, further comprising a control circuit for switching the switch means of the circuit Y to a side for charging the capacitance sensor.
定レベルより低下した場合に、前記回路Ｘ及び前記回路
Ｙのスイッチ手段を前記容量センサを充電する側に切り
換える制御回路を前記回路Ｙの出力に設けたことを特徴
とする請求の範囲３に記載の静電容量式物理量検出装
置。5. A control circuit for detecting the output voltage level of the circuit Y, and switching the switch means of the circuit X and the circuit Y to the side for charging the capacitance sensor when the output voltage level is lower than a predetermined level. The electrostatic capacitance type physical quantity detection device according to claim 3, wherein the electrostatic capacitance type physical quantity detection device is provided at the output of the.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP35358592A JPH06180336A (en) | 1992-12-14 | 1992-12-14 | Capacitance type physical quantity detecting device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP35358592A JPH06180336A (en) | 1992-12-14 | 1992-12-14 | Capacitance type physical quantity detecting device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06180336A true JPH06180336A (en) | 1994-06-28 |
Family
ID=18431839
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP35358592A Pending JPH06180336A (en) | 1992-12-14 | 1992-12-14 | Capacitance type physical quantity detecting device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06180336A (en) |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5973538A (en) * | 1996-06-26 | 1999-10-26 | Sumitomo Medal Industries, Ltd. | Sensor circuit |
| WO1999042848A3 (en) * | 1998-02-19 | 1999-11-25 | Sumitomo Metal Ind | Capacitance detection system and method |
| US6194888B1 (en) | 1998-02-05 | 2001-02-27 | Sumitomo Metal Industries Limited | Impedance-to-voltage converter and converting method |
| US6335642B1 (en) | 1998-01-23 | 2002-01-01 | Sumitomo Metal Industries Limited | Impedance-to-voltage converter |
| WO2004017036A2 (en) * | 2002-08-16 | 2004-02-26 | Rosemount Inc. | Pressure measurement device including a capacitive pressure sensor in an amplifier feedback path |
| US6828806B1 (en) | 1999-07-22 | 2004-12-07 | Sumitomo Metal Industries, Ltd. | Electrostatic capacitance sensor, electrostatic capacitance sensor component, object mounting body and object mounting apparatus |
| US6906548B1 (en) | 2000-11-02 | 2005-06-14 | Tokyo Electron Limited | Capacitance measurement method of micro structures of integrated circuits |
| WO2007091419A1 (en) * | 2006-02-07 | 2007-08-16 | Pioneer Corporation | Electrostatic capacity detection device |
| CN103528603A (en) * | 2012-07-05 | 2014-01-22 | 北斗电子工业株式会社 | Static capacitive moisture detector |
| JP2016510547A (en) * | 2013-01-17 | 2016-04-07 | マイクロチップ テクノロジー インコーポレイテッドＭｉｃｒｏｃｈｉｐ Ｔｅｃｈｎｏｌｏｇｙ Ｉｎｃｏｒｐｏｒａｔｅｄ | Physical force capacity type touch sensor |
| CN113075459A (en) * | 2021-03-18 | 2021-07-06 | 合肥恒钧检测技术有限公司 | Electrostatic capacity detection device |
-
1992
- 1992-12-14 JP JP35358592A patent/JPH06180336A/en active Pending
Cited By (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5973538A (en) * | 1996-06-26 | 1999-10-26 | Sumitomo Medal Industries, Ltd. | Sensor circuit |
| US6335642B1 (en) | 1998-01-23 | 2002-01-01 | Sumitomo Metal Industries Limited | Impedance-to-voltage converter |
| US6194888B1 (en) | 1998-02-05 | 2001-02-27 | Sumitomo Metal Industries Limited | Impedance-to-voltage converter and converting method |
| WO1999042848A3 (en) * | 1998-02-19 | 1999-11-25 | Sumitomo Metal Ind | Capacitance detection system and method |
| AU731610B2 (en) * | 1998-02-19 | 2001-04-05 | Tokyo Electron Limited | Capacitance detection system and method |
| US6326795B1 (en) | 1998-02-19 | 2001-12-04 | Sumitomo Metal Industries, Ltd. | Capacitance detection system and method |
| US6828806B1 (en) | 1999-07-22 | 2004-12-07 | Sumitomo Metal Industries, Ltd. | Electrostatic capacitance sensor, electrostatic capacitance sensor component, object mounting body and object mounting apparatus |
| US7161360B2 (en) | 1999-07-22 | 2007-01-09 | Tokyo Electron Ltd. | Electrostatic capacitance sensor, electrostatic capacitance sensor component, object mounting body and object mounting apparatus |
| US6906548B1 (en) | 2000-11-02 | 2005-06-14 | Tokyo Electron Limited | Capacitance measurement method of micro structures of integrated circuits |
| US7176706B2 (en) | 2000-11-02 | 2007-02-13 | Tokyo Electron Limited | Capacitance measurement method of micro structures of integrated circuits |
| US6828802B2 (en) | 2002-08-16 | 2004-12-07 | Rosemount Inc. | Pressure measurement device including a capacitive sensor in an amplifier feedback path |
| WO2004017036A3 (en) * | 2002-08-16 | 2004-03-25 | Rosemount Inc | Pressure measurement device including a capacitive pressure sensor in an amplifier feedback path |
| JP2005535900A (en) * | 2002-08-16 | 2005-11-24 | ローズマウント インコーポレイテッド | Pressure measuring device with capacitive pressure sensor in amplifier feedback path |
| WO2004017036A2 (en) * | 2002-08-16 | 2004-02-26 | Rosemount Inc. | Pressure measurement device including a capacitive pressure sensor in an amplifier feedback path |
| DE10393130B4 (en) * | 2002-08-16 | 2019-01-24 | Rosemount Inc. | A pressure measuring device with a capacitive pressure sensor in an amplifier feedback path |
| WO2007091419A1 (en) * | 2006-02-07 | 2007-08-16 | Pioneer Corporation | Electrostatic capacity detection device |
| JP4902552B2 (en) * | 2006-02-07 | 2012-03-21 | パイオニア株式会社 | Capacitance detection device |
| US8164352B2 (en) | 2006-02-07 | 2012-04-24 | Pioneer Corporation | Capacitance detecting apparatus |
| CN103528603A (en) * | 2012-07-05 | 2014-01-22 | 北斗电子工业株式会社 | Static capacitive moisture detector |
| JP2016510547A (en) * | 2013-01-17 | 2016-04-07 | マイクロチップ テクノロジー インコーポレイテッドＭｉｃｒｏｃｈｉｐ Ｔｅｃｈｎｏｌｏｇｙ Ｉｎｃｏｒｐｏｒａｔｅｄ | Physical force capacity type touch sensor |
| CN113075459A (en) * | 2021-03-18 | 2021-07-06 | 合肥恒钧检测技术有限公司 | Electrostatic capacity detection device |
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