TWI427927B - Readout circuit method thereof for converting sensing voltage - Google Patents
Readout circuit method thereof for converting sensing voltage Download PDFInfo
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Description
本發明係有關於一種讀出電路，尤指一種可補償臨界電壓的讀出電路與其訊號轉換方法。The invention relates to a readout circuit, in particular to a readout circuit capable of compensating for a threshold voltage and a signal conversion method thereof.
近年來，具觸碰面板的電子產品已成為流行產品導向，利用觸碰面板作為使用者與電子產品之間的溝通介面，可讓使用者直接透過手指觸碰模式來控制電子產品的操作，而不需透過鍵盤或滑鼠。一般而言，觸碰面板以電阻式觸碰面板及電容式觸碰面板為主，電阻式觸碰面板係以電壓降定位觸碰位置，電容式觸碰面板包含複數感應電容，根據對應於觸碰點之感應電容的電容變化，經訊號處理而定位出觸碰位置。觸碰面板通常包含感測單元與讀出電路，其中感測單元係用來感測觸碰事件以提供感測電壓，而讀出電路則用來將感測電壓轉換為讀出電壓。然而，讀出電路之內部元件的特性參數值會因不同製程、不同溫度、或元件老化等因素而發生漂移現象，導致讀出電壓發生誤差，如此可能會造成後級電路的誤動作。In recent years, electronic products with touch panels have become popular product orientation, using touch panels as a communication interface between users and electronic products, allowing users to directly control the operation of electronic products through finger touch mode. No need to use the keyboard or mouse. Generally, the touch panel is mainly a resistive touch panel and a capacitive touch panel, the resistive touch panel is positioned with a voltage drop, and the capacitive touch panel includes a plurality of sensing capacitors according to corresponding touches. The capacitance change of the sensing capacitor of the touch point is processed by the signal to locate the touch position. The touch panel typically includes a sensing unit for sensing a touch event to provide a sense voltage, and a readout circuit for converting the sense voltage to a sense voltage. However, the characteristic parameter values of the internal components of the readout circuit may drift due to factors such as different processes, different temperatures, or component aging, resulting in errors in the read voltage, which may cause malfunction of the subsequent stage circuit.
依據本發明之實施例揭露一種可補償臨界電壓的讀出電路，用來將感測單元所輸出之感測電壓轉換為讀出電壓。此種讀出電路包含第一開關、第二開關、第一儲能單元、電壓/電流轉換單元、第二儲能單元、第三開關、第四開關、以及第五開關。第一開關包含第一端、第二端與控制端，其中第一開關之第一端電連接於感測單元以接收感測電壓，第一開關之控制端用來接收第一控制訊號。第二開關包含第一端、第二端與控制端，其中第二開關之第一端用來接收電源電壓，第二開關之控制端用來接收第二控制訊號，第二開關之第二端電連接於第一開關之第二端。第一儲能單元包含第一端與第二端，其中第一儲能單元之第一端電連接於第一開關之第二端及第二開關之第二端，第一儲能單元之第二端用來提供驅動電壓。電壓/電流轉換單元電連接於第一儲能單元之第二端，用來根據驅動電壓提供充電電流。第二儲能單元係用來於根據充電電流執行充電程序以產生讀出電壓。第三開關電連接於電壓/電流轉換單元與第二儲能單元，用來根據第三控制訊號控制充電電流輸入至第二儲能單元。第四開關包含第一端、第二端及控制端，其中第四開關之第一端電連接於第二儲能單元，第四開關之第二端係用來接受參考電位，第四開關之控制端係用來接收第四控制訊號，據以重置讀出電壓。第五開關電連接於第一儲能單元與第二儲能單元，用來根據第二控制訊號將驅動電壓設定為讀出電壓。According to an embodiment of the invention, a readout circuit capable of compensating for a threshold voltage is disclosed for converting a sense voltage outputted by the sensing unit into a read voltage. The readout circuit includes a first switch, a second switch, a first energy storage unit, a voltage/current conversion unit, a second energy storage unit, a third switch, a fourth switch, and a fifth switch. The first switch includes a first end, a second end, and a control end, wherein the first end of the first switch is electrically connected to the sensing unit to receive the sensing voltage, and the control end of the first switch is used to receive the first control signal. The second switch includes a first end, a second end and a control end, wherein the first end of the second switch is for receiving a power supply voltage, the control end of the second switch is for receiving the second control signal, and the second end of the second switch Electrically connected to the second end of the first switch. The first energy storage unit includes a first end and a second end, wherein the first end of the first energy storage unit is electrically connected to the second end of the first switch and the second end of the second switch, and the first energy storage unit The two ends are used to provide the driving voltage. The voltage/current conversion unit is electrically connected to the second end of the first energy storage unit for providing a charging current according to the driving voltage. The second energy storage unit is configured to perform a charging process according to the charging current to generate a read voltage. The third switch is electrically connected to the voltage/current conversion unit and the second energy storage unit for controlling the charging current input to the second energy storage unit according to the third control signal. The fourth switch includes a first end, a second end, and a control end, wherein the first end of the fourth switch is electrically connected to the second energy storage unit, the second end of the fourth switch is used to receive the reference potential, and the fourth switch The control terminal is configured to receive the fourth control signal to reset the read voltage. The fifth switch is electrically connected to the first energy storage unit and the second energy storage unit for setting the driving voltage to the read voltage according to the second control signal.
依據本發明之實施例揭露另揭露一種訊號轉換方法，用於可補償臨界電壓的讀出電路，據以將感測單元所輸出之感測電壓轉換為讀出電壓。此讀出電路包含第一開關、第二開關、第一儲能單元、電壓/電流轉換單元、第二儲能單元、第三開關、第四開關、以及第五開關，其中第一開關係用來根據第一控制訊號將感測電壓輸入為內部電壓，第二開關係用來根據第二控制訊號將電源電壓輸入為內部電壓，第一儲能單元係用來根據內部電壓調整驅動電壓，電壓/電流轉換單元係用來根據驅動電壓提供充電電流，第二儲能單元係用來根據充電電流執行充電程序以產生讀出電壓，第三開關係用來根據第三控制訊號控制充電電流輸入至第二儲能單元，第四開關係用來根據第四控制訊號重置讀出電壓，第五開關係用來根據第二控制訊號將驅動電壓設定為讀出電壓。此種訊號轉換方法包含：於第一時段內，提供第二控制訊號以導通第二開關，據以將電源電壓輸入為內部電壓；於第一時段內，第二控制訊號另導通第五開關，據以將驅動電壓設定為讀出電壓；於第一時段內，提供第三控制訊號以導通第三開關，使電壓/電流轉換單元所提供之充電電流可輸入至第二儲能單元，進而將讀出電壓與驅動電壓上拉為電源電壓與臨界電壓之第一差值電壓，其中臨界電壓係為電壓/電流轉換單元之特性參數值；於第二時段內，提供第四控制訊號以導通第四開關，據以將讀出電壓重置為參考電位；於第二時段內，提供第二控制訊號以截止第二開關以及第五開關，據以使驅動電壓成為浮接電壓；於第三時段內，提供第一控制訊號以導通第一開關，據以將內部電壓從電源電壓切換為感測電壓；於第三時段內，第一儲能單元根據內部電壓之電壓切換將驅動電壓從第一差值電壓調整為感測電壓與臨界電壓之第二差值電壓；於第三時段內，電壓/電流轉換單元根據第二差值電壓提供充電電流；以及於第三時段內，提供第三控制訊號以導通第三開關，使充電電流輸入至第二儲能單元以上拉讀出電壓。According to an embodiment of the present invention, a signal conversion method for reading a threshold voltage can be used to convert a sensing voltage outputted by a sensing unit into a read voltage. The readout circuit includes a first switch, a second switch, a first energy storage unit, a voltage/current conversion unit, a second energy storage unit, a third switch, a fourth switch, and a fifth switch, wherein the first open relationship is used The sensing voltage is input as an internal voltage according to the first control signal, and the second opening relationship is used to input the power voltage into an internal voltage according to the second control signal, and the first energy storage unit is configured to adjust the driving voltage according to the internal voltage, and the voltage The /current conversion unit is configured to provide a charging current according to the driving voltage, the second energy storage unit is configured to perform a charging procedure according to the charging current to generate the readout voltage, and the third open relationship is used to control the charging current input according to the third control signal The second energy storage unit is configured to reset the read voltage according to the fourth control signal, and the fifth open relationship is configured to set the driving voltage to the read voltage according to the second control signal. The signal conversion method includes: providing a second control signal to turn on the second switch during the first time period, thereby inputting the power voltage into the internal voltage; and in the first time period, the second control signal is further turned on by the fifth switch. According to the driving voltage is set as the read voltage; during the first time period, the third control signal is provided to turn on the third switch, so that the charging current provided by the voltage/current conversion unit can be input to the second energy storage unit, and then The read voltage and the driving voltage are pulled up to be the first difference voltage between the power supply voltage and the threshold voltage, wherein the threshold voltage is a characteristic parameter value of the voltage/current conversion unit; and during the second time period, the fourth control signal is provided to be turned on. a fourth switch, according to which the read voltage is reset to a reference potential; during the second time period, a second control signal is provided to turn off the second switch and the fifth switch, so that the driving voltage becomes a floating voltage; Providing a first control signal to turn on the first switch, thereby switching the internal voltage from the power voltage to the sensing voltage; during the third time period, the first energy storage unit is internally The voltage voltage switching adjusts the driving voltage from the first difference voltage to a second difference voltage between the sensing voltage and the threshold voltage; and during the third time period, the voltage/current converting unit provides the charging current according to the second difference voltage; During the third time period, a third control signal is provided to turn on the third switch, and the charging current is input to the second energy storage unit to pull the read voltage.
依據本發明之實施例另揭露一種可補償臨界電壓的讀出電路，用來將感測單元所輸出之感測電壓轉換為讀出電壓。此種讀出電路包含第一開關、第二開關、第一儲能單元、電壓/電流轉換單元、第二儲能單元、第三開關、第四開關、以及第五開關。第一開關電連接於感測單元，用來透過第一控制訊號之控制將感測電壓輸入為內部電壓。第二開關電連接於第一開關，用來透過第二控制訊號之控制將電源電壓輸入為內部電壓。第一儲能單元電連接於第一開關與第二開關，用來根據內部電壓調整驅動電壓。電壓/電流轉換單元電連接於第一儲能單元，用來根據驅動電壓提供充電電流。第二儲能單元係用來根據充電電流執行充電程序以產生讀出電壓。第三開關電連接於電壓/電流轉換單元與第二儲能單元之間，用來透過第三控制訊號之控制將充電電流輸入至第二儲能單元。第四開關電連接於第二儲能單元，用來透過第四控制訊號之控制以重置讀出電壓。第五開關電連接於第一儲能單元與第二儲能單元，用來透過第二控制訊號之控制將驅動電壓設定為讀出電壓。在此讀出電路的運作中，當第一開關在導通狀態時，第二開關係在截止狀態，當第二開關在導通狀態時，第一開關係在截止狀態。According to an embodiment of the invention, a readout circuit capable of compensating for a threshold voltage is used to convert the sense voltage outputted by the sensing unit into a read voltage. The readout circuit includes a first switch, a second switch, a first energy storage unit, a voltage/current conversion unit, a second energy storage unit, a third switch, a fourth switch, and a fifth switch. The first switch is electrically connected to the sensing unit for inputting the sensing voltage into an internal voltage through control of the first control signal. The second switch is electrically connected to the first switch for inputting the power voltage into the internal voltage through the control of the second control signal. The first energy storage unit is electrically connected to the first switch and the second switch for adjusting the driving voltage according to the internal voltage. The voltage/current conversion unit is electrically connected to the first energy storage unit for providing a charging current according to the driving voltage. The second energy storage unit is configured to perform a charging process based on the charging current to generate a read voltage. The third switch is electrically connected between the voltage/current conversion unit and the second energy storage unit for inputting the charging current to the second energy storage unit through the control of the third control signal. The fourth switch is electrically connected to the second energy storage unit for controlling the read voltage by the control of the fourth control signal. The fifth switch is electrically connected to the first energy storage unit and the second energy storage unit for setting the driving voltage to the read voltage through the control of the second control signal. In the operation of the readout circuit, when the first switch is in the on state, the second on relationship is in the off state, and when the second switch is in the on state, the first on relationship is in the off state.
下文依本發明讀出電路與其訊號轉換方法，特舉實施例配合所附圖式作詳細說明，但所提供之實施例並非用以限制本發明所涵蓋的範圍，而方法流程步驟編號更非用以限制其執行先後次序，任何由方法步驟重新組合之執行流程，所產生具有均等功效的方法，皆為本發明所涵蓋的範圍。In the following, the readout circuit and its signal conversion method according to the present invention are described in detail with reference to the accompanying drawings, but the embodiments are not intended to limit the scope of the present invention, and the method flow number is not used. In order to limit the order of execution, any method of re-combining the execution of the method steps, resulting in equal efficiency, is within the scope of the present invention.
第1圖為本發明讀出電路之第一實施例示意圖。如第1圖所示，讀出電路100包含第一電晶體110、第二電晶體120、電容125、以及第三電晶體130，其中第二電晶體120與第三電晶體130之電路功能為開關，第一電晶體110之電路功能為電壓至電流轉換。讀出電路100可將感測單元190所產生之感測電壓Vs1轉換為讀出電壓Vout1。Figure 1 is a schematic view of a first embodiment of a readout circuit of the present invention. As shown in FIG. 1, the readout circuit 100 includes a first transistor 110, a second transistor 120, a capacitor 125, and a third transistor 130. The circuit functions of the second transistor 120 and the third transistor 130 are The circuit function of the first transistor 110 is a voltage to current conversion. The readout circuit 100 can convert the sensing voltage Vs1 generated by the sensing unit 190 into the readout voltage Vout1.
在讀出電路100的運作中，第一電晶體110係用來根據感測電壓Vs1提供充電電流Ich1，第二電晶體120係用來透過第一控制訊號Sc1之控制將充電電流Ich1輸入至電容125，電容125係用來根據從第二電晶體120輸入之充電電流Ich1執行充電程序以產生讀出電壓Vout1，第三開關130係用來透過第二控制訊號Sc2之控制以重置讀出電壓Vout1。當第二電晶體120導通使充電電流Ich1可輸入電容125時，第一電晶體110所提供的充電電流Ich1可以下列公式(1)表示。In the operation of the readout circuit 100, the first transistor 110 is used to provide a charging current Ich1 according to the sensing voltage Vs1, and the second transistor 120 is used to input the charging current Ich1 to the capacitor through the control of the first control signal Sc1. 125. The capacitor 125 is configured to perform a charging process to generate the read voltage Vout1 according to the charging current Ich1 input from the second transistor 120, and the third switch 130 is configured to reset the read voltage by controlling the second control signal Sc2. Vout1. When the second transistor 120 is turned on so that the charging current Ich1 can be input to the capacitor 125, the charging current Ich1 supplied from the first transistor 110 can be expressed by the following formula (1).
Ich 1=K (Vdd -Vs 1-Vth 1)2 …公式(1) Ich 1= K ( Vdd - Vs 1- Vth 1) 2 ...Formula (1)
在公式(1)中，K為製程參數，Vdd為電源電壓，Vth1為第一電晶體110之臨界電壓。然而臨界電壓Vth1會因不同製程、不同溫度、或電晶體老化等因素而變化，甚至同一製程不同批次所生產之電晶體也會有臨界電壓漂移現象。所以，即使輸入相同感測電壓Vs1至第一電晶體110，第一電晶體110可能因臨界電壓漂移而輸出不同的充電電流Ich1，導致讀出電壓Vout1發生誤差。In the formula (1), K is a process parameter, Vdd is a power supply voltage, and Vth1 is a threshold voltage of the first transistor 110. However, the threshold voltage Vth1 may vary due to factors such as different processes, different temperatures, or aging of the transistor, and even the transistors produced in different batches of the same process may have a critical voltage drift phenomenon. Therefore, even if the same sensing voltage Vs1 is input to the first transistor 110, the first transistor 110 may output a different charging current Ich1 due to the threshold voltage drift, resulting in an error in the read voltage Vout1.
第2圖為本發明讀出電路之第二實施例示意圖。如第2圖所示，讀出電路200包含第一開關210、第二開關220、第一儲能單元215、電壓/電流轉換單元225、第三開關230、第二儲能單元235、第四開關240、以及第五開關250。讀出電路200可將感測單元290所產生之感測電壓Vs轉換為讀出電壓Vout。Figure 2 is a schematic view showing a second embodiment of the readout circuit of the present invention. As shown in FIG. 2, the readout circuit 200 includes a first switch 210, a second switch 220, a first energy storage unit 215, a voltage/current conversion unit 225, a third switch 230, a second energy storage unit 235, and a fourth The switch 240 and the fifth switch 250. The readout circuit 200 can convert the sensed voltage Vs generated by the sensing unit 290 into the readout voltage Vout.
在讀出電路200的運作中，第一開關210係用來透過第一控制訊號Sct1之控制將感測電壓Vs輸入為內部電壓Vx，而第二開關220係用來透過第二控制訊號Sct2之控制將電源電壓Vdd輸入為內部電壓Vx，第一開關210與第二開關220並不會同時導通，但第一開關210與第二開關220可同時截止，當第一開關210在導通狀態時，第二開關220係在截止狀態，或者當第二開關220在導通狀態時，第一開關210係在截止狀態。第一儲能單元215係用來根據內部電壓Vx調整驅動電壓Vdr。電壓/電流轉換單元225係用來根據驅動電壓Vdr提供充電電流Ich。第三開關230係用來透過第三控制訊號Sct3之控制將充電電流Ich輸入至第二儲能單元235。第二儲能單元235係用來根據充電電流Ich執行充電程序以產生讀出電壓Vout。第四開關240係用來透過第四控制訊號Sct4之控制以重置讀出電壓Vout。第五開關250係用來透過第二控制訊號Sct2之控制將驅動電壓Vdr設定為讀出電壓Vout。In the operation of the readout circuit 200, the first switch 210 is configured to input the sense voltage Vs into the internal voltage Vx through the control of the first control signal Sct1, and the second switch 220 is configured to transmit the second control signal Sct2. Controlling the power supply voltage Vdd as the internal voltage Vx, the first switch 210 and the second switch 220 are not simultaneously turned on, but the first switch 210 and the second switch 220 can be simultaneously turned off, when the first switch 210 is in the on state, The second switch 220 is in an off state, or when the second switch 220 is in an on state, the first switch 210 is in an off state. The first energy storage unit 215 is for adjusting the driving voltage Vdr according to the internal voltage Vx. The voltage/current conversion unit 225 is for supplying a charging current Ich in accordance with the driving voltage Vdr. The third switch 230 is configured to input the charging current Ich to the second energy storage unit 235 through the control of the third control signal Sct3. The second energy storage unit 235 is configured to perform a charging process according to the charging current Ich to generate the readout voltage Vout. The fourth switch 240 is used to control the read voltage Vout through the control of the fourth control signal Sct4. The fifth switch 250 is configured to set the driving voltage Vdr to the read voltage Vout by the control of the second control signal Sct2.
在第2圖所示的實施例中，第一開關210包含第一電晶體211，第二開關220包含第二電晶體221，第一儲能單元215包含第一電容216，第三開關230包含第三電晶體231，第二儲能單元235包含第二電容236，第四開關240包含第四電晶體241，第五開關250包含第五電晶體251，電壓/電流轉換單元225包含第六電晶體226。第一電晶體211、第二電晶體221、第三電晶體231、第五電晶體251與第六電晶體226係為P型薄膜電晶體(Thin Film Transistor)或P型場效電晶體(Field Effect Transistor)，第四電晶體241係為N型薄膜電晶體或N型場效電晶體。請注意，第一電晶體211至第六電晶體226並不一定要設定為如上所述之P型電晶體或N型電晶體，而可根據控制訊號、電源電壓或參考電位的不同輸入設計而作不同設定，譬如若第四開關240係依具低準位電壓之第四控制訊號Sct4以重置讀出電壓Vout，則第四開關240所包含之第四電晶體241應被設定為N型電晶體，其餘同理類推。In the embodiment shown in FIG. 2, the first switch 210 includes a first transistor 211, the second switch 220 includes a second transistor 221, the first energy storage unit 215 includes a first capacitor 216, and the third switch 230 includes The third transistor 231, the second energy storage unit 235 includes a second capacitor 236, the fourth switch 240 includes a fourth transistor 241, the fifth switch 250 includes a fifth transistor 251, and the voltage/current conversion unit 225 includes a sixth battery Crystal 226. The first transistor 211, the second transistor 221, the third transistor 231, the fifth transistor 251, and the sixth transistor 226 are P-type thin film transistors or P-type field effect transistors (Field). Effect Transistor), the fourth transistor 241 is an N-type thin film transistor or an N-type field effect transistor. Please note that the first to sixth transistors 211 to 226 do not have to be set to the P-type transistor or the N-type transistor as described above, but can be designed according to different input signals of the control signal, the power supply voltage or the reference potential. For different settings, for example, if the fourth switch 240 is based on the fourth control signal Sct4 having a low level voltage to reset the read voltage Vout, the fourth transistor 241 included in the fourth switch 240 should be set to the N type. The transistor, the rest is analogous.
第一開關210包含第一端、第二端與控制端，其中第一端電連接於感測單元290以接收感測電壓Vs，控制端用來接收第一控制訊號Sct1，第二端用來提供內部電壓Vx。第二開關220包含第一端、第二端與控制端，其中第一端用來接收電源電壓Vdd，控制端用來接收第二控制訊號Sct2，第二端電連接於第一開關210之第二端。第一儲能單元215包含第一端與第二端，其中第一端電連接於第一開關210之第二端，第二端用來提供驅動電壓Vdr。電壓/電流轉換單元225包含第一端、第二端與控制端，其中第一端用來接收電源電壓Vdd，控制端電連接於第一儲能單元215之第二端，第二端用來輸出充電電流Ich。第三開關230包含第一端、第二端與控制端，其中第一端電連接於電壓/電流轉換單元225之第二端以接收充電電流Ich，控制端用來接收第三控制訊號Sct3，第二端用來輸出充電電流Ich。第二儲能單元235包含第一端與第二端，其中第一端電連接於第三開關230之第二端以接收充電電流Ich，第二端電連接於參考電位Vref。在一實施例中，第二儲能單元235之第二端所電連接之參考電位Vref可為接地電位。第四開關240包含第一端、第二端與控制端，其中第一端電連接於第二儲能單元235之第一端，控制端用來接收第四控制訊號Sct4，第二端電連接於第二儲能單元235之第二端。第五開關250包含第一端、第二端與控制端，其中第一端電連接於第二儲能單元235之第一端以接收讀出電壓Vout，控制端用來接收第二控制訊號Sct2，第二端電連接於第一儲能單元215之第二端。The first switch 210 includes a first end, a second end, and a control end, wherein the first end is electrically connected to the sensing unit 290 to receive the sensing voltage Vs, the control end is used to receive the first control signal Sct1, and the second end is used to receive the first control signal Sct1. Provide internal voltage Vx. The second switch 220 includes a first end, a second end, and a control end, wherein the first end is configured to receive the power voltage Vdd, the control end is configured to receive the second control signal Sct2, and the second end is electrically connected to the first switch 210 Two ends. The first energy storage unit 215 includes a first end and a second end, wherein the first end is electrically connected to the second end of the first switch 210, and the second end is used to provide the driving voltage Vdr. The voltage/current conversion unit 225 includes a first end, a second end, and a control end, wherein the first end is for receiving the power voltage Vdd, the control end is electrically connected to the second end of the first energy storage unit 215, and the second end is used for The charging current Ich is output. The third switch 230 includes a first end, a second end, and a control end, wherein the first end is electrically connected to the second end of the voltage/current conversion unit 225 to receive the charging current Ich, and the control end is configured to receive the third control signal Sct3, The second end is used to output the charging current Ich. The second energy storage unit 235 includes a first end and a second end, wherein the first end is electrically connected to the second end of the third switch 230 to receive the charging current Ich, and the second end is electrically connected to the reference potential Vref. In an embodiment, the reference potential Vref electrically connected to the second end of the second energy storage unit 235 may be a ground potential. The fourth switch 240 includes a first end, a second end, and a control end, wherein the first end is electrically connected to the first end of the second energy storage unit 235, the control end is configured to receive the fourth control signal Sct4, and the second end is electrically connected At the second end of the second energy storage unit 235. The fifth switch 250 includes a first end, a second end, and a control end, wherein the first end is electrically connected to the first end of the second energy storage unit 235 to receive the read voltage Vout, and the control end is configured to receive the second control signal Sct2 The second end is electrically connected to the second end of the first energy storage unit 215.
第3圖為第2圖所示之讀出電路的工作相關訊號波形示意圖，其中橫軸為時間軸。在第3圖中，由上往下的訊號分別為第一控制訊號Sct1、第二控制訊號Sct2、第三控制訊號Sct3、第四控制訊號Sct4、驅動電壓Vdr、內部電壓Vx、以及讀出電壓Vout。如第3圖所示，於第一時段內，第一控制訊號Sct1具高準位電壓以截止第一電晶體211，第二控制訊號Sct2具低準位電壓以導通第二電晶體221與第五電晶體251，第三控制訊號Sct3具低準位電壓以導通第三電晶體231，第四控制訊號Sct4具低準位電壓以截止第四電晶體241。Fig. 3 is a schematic diagram showing the waveforms of the operation-related signals of the readout circuit shown in Fig. 2, wherein the horizontal axis is the time axis. In FIG. 3, the signals from top to bottom are the first control signal Sct1, the second control signal Sct2, the third control signal Sct3, the fourth control signal Sct4, the driving voltage Vdr, the internal voltage Vx, and the read voltage. Vout. As shown in FIG. 3, during the first time period, the first control signal Sct1 has a high level voltage to turn off the first transistor 211, and the second control signal Sct2 has a low level voltage to turn on the second transistor 221 and the first The fifth transistor 251, the third control signal Sct3 has a low level voltage to turn on the third transistor 231, and the fourth control signal Sct4 has a low level voltage to turn off the fourth transistor 241.
此時，內部電壓Vx因第二電晶體221導通而被設定為電源電壓Vdd，驅動電壓Vdr因第五電晶體251導通而被設定為讀出電壓Vout，從而驅動第六電晶體226提供充電電流Ich經由第三電晶體231對第二電容236充電，據以將讀出電壓Vout與驅動電壓Vdr上拉為第一差值電壓Vdd-Vth，其中Vth為第六電晶體226之臨界電壓，換句話說，臨界電壓Vth即為電壓/電流轉換單元225之特性參數值。At this time, the internal voltage Vx is set to the power supply voltage Vdd due to the second transistor 221 being turned on, and the driving voltage Vdr is set to the read voltage Vout due to the fifth transistor 251 being turned on, thereby driving the sixth transistor 226 to supply the charging current. The Ich charges the second capacitor 236 via the third transistor 231, thereby pulling up the read voltage Vout and the driving voltage Vdr into a first difference voltage Vdd-Vth, where Vth is the threshold voltage of the sixth transistor 226, In other words, the threshold voltage Vth is the characteristic parameter value of the voltage/current conversion unit 225.
於第二時段內，第一控制訊號Sct1具高準位電壓以截止第一電晶體211，第二控制訊號Sct2具高準位電壓以截止第二電晶體221與第五電晶體251，第三控制訊號Sct3具高準位電壓以截止第三電晶體231，第四控制訊號Sct4具高準位電壓以導通第四電晶體241。此時，讀出電壓Vout被重置為參考電位Vref，驅動電壓Vdr因第五電晶體251截止而成為浮接電壓。During the second time period, the first control signal Sct1 has a high level voltage to turn off the first transistor 211, and the second control signal Sct2 has a high level voltage to turn off the second transistor 221 and the fifth transistor 251, and third. The control signal Sct3 has a high level voltage to turn off the third transistor 231, and the fourth control signal Sct4 has a high level voltage to turn on the fourth transistor 241. At this time, the read voltage Vout is reset to the reference potential Vref, and the drive voltage Vdr becomes a floating voltage due to the fifth transistor 251 being turned off.
於第三時段內，第一控制訊號Sct1具低準位電壓以導通第一電晶體211，第二控制訊號Sct2具高準位電壓以截止第二電晶體221與第五電晶體251，第三控制訊號Sct3具低準位電壓以導通第三電晶體231，第四控制訊號Sct4具低準位電壓以截止第四電晶體241。此時，內部電壓Vx因第一電晶體211導通而從電源電壓Vdd切換為感測電壓Vs，另由於驅動電壓Vdr仍保持浮接狀態，所以可藉由第一電容216的耦合作用將驅動電壓Vdr由第一差值電壓Vdd-Vth切換為第二差值電壓Vs-Vth，亦即內部電壓Vx與驅動電壓Vdr係被同步下拉壓差ΔV=Vdd-Vs。因此在第三時段由第六電晶體226所提供的充電電流Ich可以下列公式(2)表示。During the third time period, the first control signal Sct1 has a low level voltage to turn on the first transistor 211, and the second control signal Sct2 has a high level voltage to turn off the second transistor 221 and the fifth transistor 251, and third. The control signal Sct3 has a low level voltage to turn on the third transistor 231, and the fourth control signal Sct4 has a low level voltage to turn off the fourth transistor 241. At this time, the internal voltage Vx is switched from the power supply voltage Vdd to the sensing voltage Vs due to the conduction of the first transistor 211, and since the driving voltage Vdr remains in the floating state, the driving voltage can be driven by the coupling of the first capacitor 216. Vdr is switched from the first difference voltage Vdd-Vth to the second difference voltage Vs-Vth, that is, the internal voltage Vx and the driving voltage Vdr are synchronously pulled down by a voltage difference ΔV=Vdd-Vs. Therefore, the charging current Ich supplied from the sixth transistor 226 in the third period can be expressed by the following formula (2).
Ich =K (Vdd -Vs )2 …公式(2) Ich = K ( Vdd - Vs ) 2 ...Formula (2)
由公式(2)可知充電電流Ich實質上不受第六電晶體226之臨界電壓Vth所影響，而此穩定的充電電流Ich即可經由第三電晶體231對第二電容236充電以上拉讀出電壓Vout。也就是說，由於讀出電路200具臨界電壓補償機制，即使第六電晶體226之臨界電壓Vth因不同製程、不同溫度、老化或其他因素而變化，電壓/電流轉換單元225根據相同感測電壓Vs所提供的充電電流Ich仍相同，據以避免讀出電壓Vout發生誤差。It can be seen from the formula (2) that the charging current Ich is substantially unaffected by the threshold voltage Vth of the sixth transistor 226, and the stable charging current Ich can be charged to the second capacitor 236 via the third transistor 231. Voltage Vout. That is, since the readout circuit 200 has a threshold voltage compensation mechanism, even if the threshold voltage Vth of the sixth transistor 226 varies due to different processes, different temperatures, aging, or other factors, the voltage/current conversion unit 225 is based on the same sense voltage. The charging current Ich provided by Vs is still the same, in order to avoid an error in the read voltage Vout.
第4圖為本發明訊號轉換方法的流程圖。第4圖所示之流程990係為基於第2圖所示之讀出電路200的訊號轉換方法。流程990所示之訊號轉換方法包含下列步驟：步驟S910：於第一時段內，提供第二控制訊號Sct2以導通第二開關220，據以將電源電壓Vdd輸入為內部電壓Vx；步驟S915：於第一時段內，第二控制訊號Sct2另導通第五開關250，據以將驅動電壓Vdr設定為讀出電壓Vout；步驟S920：於第一時段內，提供第三控制訊號Sct3以導通第三開關230，使電壓/電流轉換單元225所提供之充電電流Ich可輸入至第二儲能單元235，進而將讀出電壓Vout與驅動電壓Vdr上拉為第一差值電壓Vdd-Vth，其中臨界電壓Vth係為電壓/電流轉換單元225之特性參數值；步驟S925：於第二時段內，提供第四控制訊號Sct4以導通第四開關240，據以將讀出電壓Vout重置為參考電位Vref；步驟S930：於第二時段內，提供第二控制訊號Sct2以截止第五開關250，據以使驅動電壓Vdr成為浮接電壓；步驟S935：於第三時段內，提供第一控制訊號Sct1以導通第一開關210，據以將內部電壓Vx從電源電壓Vdd切換為感測電壓Vs；步驟S940：於第三時段內，第一儲能單元215根據內部電壓Vx之電壓切換將驅動電壓Vdr從第一差值電壓Vdd-Vth調整為第二差值電壓Vs-Vth；步驟S945：於第三時段內，電壓/電流轉換單元225根據第二差值電壓Vs-Vth提供充電電流Ich；以及步驟S950：於第三時段內，提供第三控制訊號Sct3以導通第三開關230，使充電電流Ich輸入至第二儲能單元235以上拉讀出電壓Vout。Figure 4 is a flow chart of the signal conversion method of the present invention. The flow 990 shown in Fig. 4 is a signal conversion method based on the readout circuit 200 shown in Fig. 2. The signal conversion method shown in the process 990 includes the following steps: Step S910: During the first time period, the second control signal Sct2 is provided to turn on the second switch 220, thereby inputting the power voltage Vdd into the internal voltage Vx; step S915: During the first time period, the second control signal Sct2 is further turned on by the fifth switch 250, so as to set the driving voltage Vdr to the read voltage Vout; and in step S920, the third control signal Sct3 is provided to turn on the third switch in the first time period. 230, the charging current Ich provided by the voltage/current conversion unit 225 can be input to the second energy storage unit 235, thereby pulling up the read voltage Vout and the driving voltage Vdr into a first difference voltage Vdd-Vth, wherein the threshold voltage Vth is the characteristic parameter value of the voltage/current conversion unit 225; step S925: during the second time period, providing the fourth control signal Sct4 to turn on the fourth switch 240, thereby resetting the read voltage Vout to the reference potential Vref; Step S930: In the second time period, the second control signal Sct2 is provided to turn off the fifth switch 250, so that the driving voltage Vdr becomes the floating voltage; step S935: providing the first control in the third time period No. Sct1 to turn on the first switch 210, thereby switching the internal voltage Vx from the power supply voltage Vdd to the sensing voltage Vs; Step S940: in the third time period, the first energy storage unit 215 will drive according to the voltage switching of the internal voltage Vx The voltage Vdr is adjusted from the first difference voltage Vdd-Vth to the second difference voltage Vs-Vth; step S945: in the third period, the voltage/current conversion unit 225 supplies the charging current Ich according to the second difference voltage Vs-Vth And step S950: in the third period, the third control signal Sct3 is provided to turn on the third switch 230, and the charging current Ich is input to the second energy storage unit 235 to pull the readout voltage Vout.
在上述訊號轉換方法的流程990中，參考電位Vref可為接地電位，第二時段係在第一時段之後且第三時段係在第二時段之後，亦即第一時段、第二時段與第三時段係不互相重疊。於第一時段內之程序另包含提供第一控制訊號Sct1以截止第一開關210，以及提供第四控制訊號Sct4以截止第四開關240。於第二時段內之程序另包含提供第一控制訊號Sct1以截止第一開關210，以及提供第三控制訊號Sct3以截止第三開關230。於第三時段內之程序另包含提供第二控制訊號Sct2以截止第二開關220與第五開關250，以及提供第四控制訊號Sct4以截止第四開關240。In the flow 990 of the above signal conversion method, the reference potential Vref may be a ground potential, the second time period is after the first time period and the third time period is after the second time period, that is, the first time period, the second time period, and the third time. The time periods do not overlap each other. The program in the first time period further includes providing a first control signal Sct1 to turn off the first switch 210, and providing a fourth control signal Sct4 to turn off the fourth switch 240. The program in the second time period further includes providing the first control signal Sct1 to turn off the first switch 210, and providing the third control signal Sct3 to turn off the third switch 230. The program in the third time period further includes providing the second control signal Sct2 to turn off the second switch 220 and the fifth switch 250, and providing the fourth control signal Sct4 to turn off the fourth switch 240.
綜上所述，在本發明讀出電路的運作中，電壓/電流轉換單元所使用電晶體的臨界電壓係可被補償，據以使電壓/電流轉換單元所提供之充電電流不受臨界電壓影響，所以即使臨界電壓因不同製程、不同溫度、老化或其他因素而變化，讀出電路仍可精確地將感測電壓轉換為讀出電壓。In summary, in the operation of the readout circuit of the present invention, the threshold voltage of the transistor used in the voltage/current conversion unit can be compensated, so that the charging current provided by the voltage/current conversion unit is not affected by the threshold voltage. Therefore, even if the threshold voltage varies due to different processes, different temperatures, aging, or other factors, the readout circuit can accurately convert the sense voltage into a read voltage.
雖然本發明已以實施例揭露如上，然其並非用以限定本發明，任何具有本發明所屬技術領域之通常知識者，在不脫離本發明之精神和範圍內，當可作各種更動與潤飾，因此本發明之保護範圍當視後附之申請專利範圍所界定者為準。While the present invention has been described above by way of example, it is not intended to limit the invention, and the invention may be modified and modified without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.
100、200．．．讀出電路100, 200. . . Readout circuit
110、211．．．第一電晶體110, 211. . . First transistor
120、221．．．第二電晶體120, 221. . . Second transistor
125．．．電容125. . . capacitance
130、231．．．第三電晶體130, 231. . . Third transistor
190、290．．．感測單元190, 290. . . Sensing unit
210．．．第一開關210. . . First switch
215．．．第一儲能單元215. . . First energy storage unit
216．．．第一電容216. . . First capacitor
220．．．第二開關220. . . Second switch
225．．．電壓/電流轉換單元225. . . Voltage/current conversion unit
226．．．第六電晶體226. . . Sixth transistor
230．．．第三開關230. . . Third switch
235‧‧‧第二儲能單元235‧‧‧Second energy storage unit
236‧‧‧第二電容236‧‧‧second capacitor
240‧‧‧第四開關240‧‧‧fourth switch
241‧‧‧第四電晶體241‧‧‧4th transistor
250‧‧‧第五開關250‧‧‧ fifth switch
251‧‧‧第五電晶體251‧‧‧ fifth transistor
990‧‧‧流程990‧‧‧ Process
Ich、Ich1‧‧‧充電電流Ich, Ich1‧‧‧Charging current
S910~S950‧‧‧步驟S910~S950‧‧‧Steps
Sc1、Sct1‧‧‧第一控制訊號Sc1, Sct1‧‧‧ first control signal
Sc2、Sct2‧‧‧第二控制訊號Sc2, Sct2‧‧‧ second control signal
Sct3‧‧‧第三控制訊號Sct3‧‧‧ third control signal
Sct4‧‧‧第四控制訊號Sct4‧‧‧ fourth control signal
Vdd‧‧‧電源電壓Vdd‧‧‧Power supply voltage
Vdr‧‧‧驅動電壓Vdr‧‧‧ drive voltage
Vout、Vout1‧‧‧讀出電壓Vout, Vout1‧‧‧ read voltage
Vref‧‧‧參考電位Vref‧‧‧ reference potential
Vs、Vs1‧‧‧感測電壓Vs, Vs1‧‧‧ sense voltage
Vth、Vth1‧‧‧臨界電壓Vth, Vth1‧‧‧ threshold voltage
Vx‧‧‧內部電壓Vx‧‧‧ internal voltage
△V‧‧‧壓差△V‧‧‧ differential pressure
第1圖為本發明讀出電路之第一實施例示意圖。Figure 1 is a schematic view of a first embodiment of a readout circuit of the present invention.
第2圖為本發明讀出電路之第二實施例示意圖。Figure 2 is a schematic view showing a second embodiment of the readout circuit of the present invention.
第3圖為第2圖所示之讀出電路的工作相關訊號波形示意圖，其中橫軸為時間軸。Fig. 3 is a schematic diagram showing the waveforms of the operation-related signals of the readout circuit shown in Fig. 2, wherein the horizontal axis is the time axis.
第4圖為本發明訊號轉換方法的流程圖。Figure 4 is a flow chart of the signal conversion method of the present invention.
200．．．讀出電路200. . . Readout circuit
210．．．第一開關210. . . First switch
211．．．第一電晶體211. . . First transistor
215．．．第一儲能單元215. . . First energy storage unit
216．．．第一電容216. . . First capacitor
220．．．第二開關220. . . Second switch
221．．．第二電晶體221. . . Second transistor
225．．．電壓/電流轉換單元225. . . Voltage/current conversion unit
226．．．第六電晶體226. . . Sixth transistor
230．．．第三開關230. . . Third switch
231．．．第三電晶體231. . . Third transistor
235．．．第二儲能單元235. . . Second energy storage unit
236．．．第二電容236. . . Second capacitor
240．．．第四開關240. . . Fourth switch
241．．．第四電晶體241. . . Fourth transistor
250．．．第五開關250. . . Fifth switch
251．．．第五電晶體251. . . Fifth transistor
290．．．感測單元290. . . Sensing unit
Ich．．．充電電流Ich. . . recharging current
Sct1．．．第一控制訊號Sct1. . . First control signal
Sct2．．．第二控制訊號Sct2. . . Second control signal
Sct3．．．第三控制訊號Sct3. . . Third control signal
Sct4．．．第四控制訊號Sct4. . . Fourth control signal
Vdd．．．電源電壓Vdd. . . voltage
Vdr．．．驅動電壓Vdr. . . Driving voltage
Vout．．．讀出電壓Vout. . . Read voltage
Vref．．．參考電位Vref. . . Reference potential
Vs．．．感測電壓Vs. . . Sense voltage
Vx．．．內部電壓Vx. . . Internal voltage
Claims (19)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| TW99119304A TWI427927B (en) | 2010-06-14 | 2010-06-14 | Readout circuit method thereof for converting sensing voltage |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| TW99119304A TWI427927B (en) | 2010-06-14 | 2010-06-14 | Readout circuit method thereof for converting sensing voltage |
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| Publication Number | Publication Date |
|---|---|
| TW201145830A TW201145830A (en) | 2011-12-16 |
| TWI427927B true TWI427927B (en) | 2014-02-21 |
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| TW99119304A TWI427927B (en) | 2010-06-14 | 2010-06-14 | Readout circuit method thereof for converting sensing voltage |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN105051549B (en) * | 2013-03-29 | 2017-09-26 | 东芝三菱电机产业系统株式会社 | Voltage measuring device |
| TWI684089B (en) * | 2019-04-29 | 2020-02-01 | 世界先進積體電路股份有限公司 | Voltage regulation circuit |
| US10719097B1 (en) | 2019-06-13 | 2020-07-21 | Vanguard International Semiconductor Corporation | Voltage regulation circuit suitable to provide output voltage to core circuit |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5043820A (en) * | 1989-03-27 | 1991-08-27 | Hughes Aircraft Company | Focal plane array readout employing one capacitive feedback transimpedance amplifier for each column |
| US20080111714A1 (en) * | 2006-11-14 | 2008-05-15 | Viktor Kremin | Capacitance to code converter with sigma-delta modulator |
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2010
- 2010-06-14 TW TW99119304A patent/TWI427927B/en active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5043820A (en) * | 1989-03-27 | 1991-08-27 | Hughes Aircraft Company | Focal plane array readout employing one capacitive feedback transimpedance amplifier for each column |
| US20080111714A1 (en) * | 2006-11-14 | 2008-05-15 | Viktor Kremin | Capacitance to code converter with sigma-delta modulator |
Non-Patent Citations (1)
| Title |
|---|
| Ming-Hua Tang; Yi-Chun Zhou; Xue-Jun Zheng; Zong-ting Guo; Chuan-Pin Cheng; Zhi Ye; Zen-Shun Hu, "A novel design of 0.25mum2.5 V 2T-2C sensing scheme for FeRAM," Solid-State and Integrated Circuit Technology, 2006. ICSICT '06. 8t * |
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| TW201145830A (en) | 2011-12-16 |
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