Readout device and method for a sensor array

Abstract

In described embodiments, a sensor array comprising a plurality of resistive elements arranged in a plurality of rows and columns is provided. The row driving unit is configured to connect a plurality of rows of resistive elements of the sensor array to a voltage source for driving the voltage source to the row of resistive elements. The row driving unit also includes a switching unit for performing a switching operation, a row driving amplifier, and a feedback instrumentation amplifier (FBIA). Each of the switching units is selectively coupled to each of the row drive amplifiers, and each of the row drive amplifiers is further coupled to each of the plurality of FBIAs. A column scanning unit for detecting a voltage signal of a resistive element includes a column operational amplifier. Each of the column operational amplifiers is further connected to a column of the sensor array.

Description

Technical Field

[0001] The present application relates to readout devices and methods for sensor arrays. Background Art

[0002] Resistive sensor arrays (RSAs) are used to enhance measurement resolution in various wearable electronic devices and health sensing related applications, including temperature and touch sensing. To greatly reduce the complexity and power consumption of the sensor system, RSAs are usually implemented with a shared row (M) and shared column (N) configuration, such that each resistor element is placed between a row electrode and a column electrode in the sensor array. However, this row-column implementation usually introduces crosstalk currents between adjacent or neighboring resistor elements that share a common row or column in the array, which results in high measurement errors when scanning the resistor elements of interest in the sensor array.

[0003] To reduce the crosstalk current effects, some known readout circuit configurations include the use of row drivers consisting of digital buffers or simply operational amplifiers for providing voltages to drive the resistive elements of the sensor array. However, these readout implementations are not suitable due to large measurement errors or requirements for large power consumption or system complexity. In addition, due to limitations imposed by the construction materials, manufacturing techniques, and sensing mechanisms of certain mechanical sensors and actuators, such known methods only evaluate RSA for resistor values ​​with high resistance (e.g., ≥100Ω).

[0004] It would therefore be desirable to provide a readout device for a sensor array that addresses the shortcomings or limitations of the prior art, or at least provides the public with a useful choice. Summary of the invention

[0005] The present invention is intended to provide new and useful devices and methods that can reduce measurement errors in a sensor array, and specifically arrange the resistor elements of the sensor array, drive a voltage source to a row of resistor elements, and detect voltage signals of the resistor elements in the sensor array to minimize errors caused by crosstalk currents induced in the sensor array.

[0006] In broad terms, the present invention proposes a readout device, which includes a sensor array, the sensor array including a plurality of resistor elements arranged in a plurality of rows and columns. One way to implement the device is to configure a row driving unit to connect a voltage source to the plurality of rows of resistor elements of the sensor array, for driving the voltage source to a row of resistor elements, wherein the row driving unit includes a plurality of switching units, a plurality of row driving amplifiers, and a plurality of feedback instrumentation amplifiers (FBIAs), wherein each of the switching units performs a switching operation and is selectively coupled to each of the row driving amplifiers, and each of the row driving amplifiers is coupled to each of the FBIAs.

[0007] In one embodiment, a resistor can be connected between a non-inverting input terminal of each of a plurality of row driver amplifiers and each switching unit, and each switching unit can be selectively coupled to the row driver amplifier via a non-inverting input terminal according to a first state or a second state of the switching unit.

[0008] In an embodiment, the row drive unit may further include a plurality of current sensing resistors, wherein each current sensing resistor may be coupled to a non-inverting input terminal of each of the plurality of row drive amplifiers, and one or more of the FBIAs amplify a voltage across one or more of the current sensing resistors.

[0009] The readout device can reduce parasitic effects attributable to at least one of parasitic resistance of one or more connections or printed circuit board (PCB) lines from the sensor array and an offset voltage applied between input terminals of a row driver amplifier.

[0010] In an embodiment, a readout device can reduce crosstalk current effects associated with reading a resistive element of interest in a selected row of a sensor array, where the crosstalk current effects are attributable to one or more adjacent resistive elements arranged in the same column or different rows as the resistive element of interest, where the adjacent resistive elements are not read in association with the reading of the resistive element of interest.

[0011] In some embodiments, the apparatus may include a column scanning unit for detecting at least one voltage signal of the resistive element, wherein the column scanning unit includes a plurality of column operational amplifiers, wherein each of the column operational amplifiers is connected to one of the plurality of columns of the sensor array.

[0012] The column scanning unit may further include a plurality of feedback resistance elements, wherein each feedback resistance element is connected between an output terminal of the column operational amplifier and an inverting input terminal of the column operational amplifier, and each of the plurality of column operational amplifiers includes a grounded non-inverting input terminal.

[0013] The sensor array may have m column connections and n row connections, and each of the plurality of resistive elements is connected between a corresponding one of the m column connections and a corresponding one of the n row connections.

[0014] In one aspect, the column scanning unit may also include multiple adjacent resistance elements that are read independently of the reading of the resistance element of interest, wherein each adjacent resistance element is connected to the inverting input terminal of each column scanning unit and a feedback resistance element corresponding to each column scanning unit.

[0015] The voltage source may be configured to apply a voltage to one or more of the resistive elements of the sensor array via the one or more switching units operating in the first state.

[0016] In an embodiment, the sensor array may be used to sense microfluidic pressure, and each of the resistive elements has a minimum resistance of 10 ohms and a maximum resistance of 200 ohms.

[0017] The sensor array may be a resistive sensor array suitable for use in small electronic devices to replicate the functionality of human skin.

[0018] When reading a resistive element of interest, zero or negligible current may be achieved through each row of multiple adjacent resistive elements associated with the resistive element of interest.

[0019] The voltage drop across each resistive element of the sensor array may be adjusted in response to determined parasitic effects attributable to parasitic resistance of one or more connections or printed circuit board (PCB) lines from the sensor array or an offset voltage applied between input terminals of a row driver amplifier.

[0020] In an embodiment, a plurality of feedback instrumentation amplifiers (FBIAs) may include an inverting input terminal and a non-inverting input terminal, wherein the non-inverting input terminal is connected to a first end of a first switching unit and a first end of a first current sensing resistor, the inverting input terminal is connected to a second end of the first switching unit and a second end of the first current sensing resistor, and the first switching unit and the current sensing resistor are connected in parallel.

[0021] A row of resistance elements may include at least one resistance element having a first end coupled to one end of the current sensing resistor and one end of the switching unit and a second end coupled to one end of an adjacent resistance element.

[0022] The resistive elements of the sensor array may include one or more resistive elements configured to detect measurable levels of voltage, current, or resistance value.

[0023] Each of the plurality of row driver amplifiers may include a non-inverting input terminal connected to the switching unit and grounded via a single resistor, wherein the non-inverting input terminal is selectively connected to a voltage source based on a state of the connected switching unit.

[0024] The output of each of the plurality of FBIAs may be connected to an inverting input terminal of each of the row driver amplifiers via a first resistor, and the inverting input terminal is further connected to the output of each of the row driver amplifiers via a second resistor, wherein the first and second resistors are connected in series between the output of each FBIA and the output of each row driver amplifier.

[0025] According to another aspect of the present invention, there is provided a non-transitory computer-readable medium including executable instructions for measuring voltage values ​​of resistance elements of a sensor array using the readout device as above.

[0026] According to another aspect of the present invention, a method for measuring a voltage value of a resistor element using a readout device is provided, the method may include the following steps: arranging a plurality of resistor elements of a sensor array; connecting the plurality of rows of resistor elements of the sensor array to a voltage source via a row driving unit, the row driving unit being used to drive the voltage source to a row of resistor elements, wherein the row driving unit includes a plurality of switching units, a plurality of row driving amplifiers, and a plurality of feedback instrumentation amplifiers (FBIAs), wherein each of the switching units is selectively coupled to each of the plurality of row driving amplifiers, and each of the row driving amplifiers is coupled to each of the plurality of FBIAs; and performing a switching operation via the plurality of switching units;

[0027] The foregoing summary is illustrative only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Embodiments of the present invention will now be explained for purposes of example only with reference to the following drawings, in which:

[0029] Figure 1 is a schematic diagram showing an inductive crosstalk current path in a resistive sensor array according to an embodiment of the present disclosure.

[0030] Figure 2 is a circuit diagram illustrating a dynamic zero current method (DZCM) circuit design for a 4×4 sensor array according to an embodiment of the present disclosure.

[0031] Figure 3A and Figure 3B is a simplified circuit diagram illustrating a zero potential method (ZPM) and a DZCM circuit design for one unmeasured resistor according to an embodiment of the present disclosure.

[0032] Figure 4 is a simplified circuit diagram illustrating a DZCM circuit model of a 2×2 sensor array including parasitic effects and crosstalk current effects according to an embodiment of the present disclosure.

[0033] Figure 5 Detailed description is given of a DZCM sensor array network extracted and analyzed using Kirchhoff's laws according to an embodiment of the present disclosure.

[0034] Fig. 6A and Figure 6BFIG. 1 is a diagram showing that, for DZCM and ZPM circuit designs according to an embodiment of the present disclosure, the resistor (R um ) are set to 200 ohms and 1 ohm respectively, the resistor of interest (R x ) for various sensor array sizes (S AR ) is a graph showing the influence of measurement error.

[0035] Figure 7 FIG. 1 is a diagram showing that, according to an embodiment of the present disclosure, for DZCM and ZPM circuit designs, the sensor array size (S AR ) is set to 2×2, the resistor of interest (R x ) for various untested resistors (R um )’s influence.

[0036] FIG. 8A to FIG. 8F is a diagram showing the relationship between the resistor of interest (R x ) is set to 1 ohm, 50 ohm, and 200 ohm unmeasured resistors (R um ), the parasitic resistance of both the row and column lines (R par ), the parasitic resistor of the column line (R parcol ) or the parasitic resistor of the row line (R parRow ) for various sensor array sizes (S ar ) is a graph showing the influence of measurement error.

[0037] 9A to 9F is a diagram showing the resistor of interest (R x ) is set to 1 ohm, 50 ohm, and 200 ohm unmeasured resistors (R um ), the offset voltage (Vos C ) or the offset voltage of the row amplifier (Vos R ) for various sensor array sizes (S ar ) is a graph showing the influence of measurement error.

[0038] Fig.10 It is shown that the Figure 1-Figure 5 A block diagram of some or all of a schematic diagram of an example computer system to perform readout of a sensor array. DETAILED DESCRIPTION

[0039] Figure 1 is a schematic diagram 100 illustrating inductive crosstalk current paths in a 3×3 resistive sensor array according to an embodiment of the present disclosure.

[0040] Referring to the circuit diagram 100, each resistor element (e.g., R 22 ) is located between the row and column electrodes using a row-column configuration. This resistive sensor array (RSA) configuration reduces the number of connections and simplifies sensor manufacturing. However, the row-column configuration has a large number of adjacent unmeasured elements R um Undesirable crosstalk occurs between Figure 1 The resistor located between the driven row electrode (the xth row electrode) and the scanned column electrode (the yth column electrode) is designated as the scanned resistance element, for example, R 22 When trying to read the value of a resistive element, other parasitic paths involving adjacent unmeasured resistors appear in parallel with the resistive element, such as Figure 1 As shown by the dotted arrow in .

[0041] For example, to determine the target resistor "R 22 ”, it is necessary to evaluate the current flowing through it (denoted as “I22”) and the voltage difference across the element (denoted as “U22”). The voltage difference ‘U22’ is equal to the voltage difference between the row and column lines, i.e. ‘Vrow2-Vcol2’. In contrast, ‘I22’ cannot be measured directly because the current ‘Icol2’ in the column line includes the current from the adjacent unmeasured resistor R um The crosstalk current, such as Figure 1 As illustrated by the dashed arrow line in . Therefore, the precise determination of 'R22' cannot be easily determined from 'Icol2' and 'U22'. The crosstalk current changes the measured value of the target element, which in turn affects the excitation acting on the resistance element to be scanned. In order to improve the measurement accuracy, a comprehensive analysis and appropriate methods are required to eliminate the errors caused by crosstalk.

[0042] The Zero Potential Method (ZPM) scheme (not shown) is used for resistive sensor arrays, but suffers from parasitic effects that lead to degradation of crosstalk current effects. The above problems arise for the following reasons:

[0043] 1. The crosstalk current effect is significantly contributed by parasitic resistances originating from connecting wires and printed circuit board (PCB) lines; and

[0044] 2. The crosstalk current effect is caused by the offset voltage of the row and column driver amplifiers.

[0045] Since these problems are inherent to the electrical components involved, eliminating these problems presents a significant challenge. In order to mitigate the above problems, a dynamic zero current method (DZCM) circuit scheme has been proposed.

[0046] Figure 2 is a circuit diagram 200 illustrating a dynamic zero current method (DZCM) circuit design for a 4×4 sensor array according to an embodiment of the present disclosure.

[0047] The operating principle of the DZCM schematic 200 involves driving both ends of adjacent unmeasured resistors to zero potential. As a result, minimal current flows through these resistors, resulting in the cutting off of the crosstalk current path. In the ZPM design, non-zero currents caused by parasitic resistances and amplifier offset voltages lead to measurement errors in low-value RSA. To address this problem, the proposed DZCM includes a feedback network within the row drive unit 210 of the readout schematic 200, which forces zero current through each row of adjacent unmeasured resistors. This feedback mechanism can flexibly adjust the node potentials of the sensor's resistor array 220 to match the varying parasitic resistances and amplifier offset voltages in the readout system.

[0048] The DZCM circuit design 200 includes a current sensing resistor, denoted as R sen , which performs the function of converting current into voltage. In order to amplify R sen The voltage across the resistor is measured using a feedback instrumentation amplifier (FBIA). The circuit design also has a switch, denoted SW1, which is closed (ON) in the row containing the measured resistor. Additionally, a switch, denoted SW, is open (OFF) in the adjacent unmeasured row. Note that Figure 2 All amplifiers depicted in are non-ideal.

[0049] In an example embodiment, a 4×4 RSA 220 featuring four row connections and four column connections is provided. To detect the output of the sensors in the array 220, the first row connection is driven to a fixed voltage, and the current on the four column connections is detected after the drive voltage is applied to the row connections. This enables measurement data to be acquired for the four cells located in the first row connection, one column at a time. By utilizing this process, four cells in a row can be measured in a single step. Once the results for all sensors in the first row have been obtained, the process is repeated for the second row, and so on, until all row connections have been measured. During scanning of a row of interest in the array 220, each resistor located in the scanned row is referred to as a resistive element of interest A (being tested), while the resistors in the remaining rows are designated as adjacent or neighboring resistors R that are not measured. um .

[0050] In an example embodiment, the readout circuit 200 includes a row driving unit 210 configured to convert a voltage source V in The multiple rows of resistor elements connected to the sensor array 220 are used to convert the voltage source V inDrive to a row of resistor elements. The row driving unit 210 includes a switching unit SW1 or SW, a plurality of row driving amplifiers and a feedback instrumentation amplifier FBIA. Each of the switching units SW1 or SW is capable of performing a switching operation and is selectively coupled to each of the row driving amplifiers. Each of the row driving amplifiers is coupled to each of the FBIAs. The device also includes a column scanning unit 230 for detecting at least one voltage signal of the resistor element. The column scanning unit 230 includes a column operational amplifier, wherein each of the column operational amplifiers is connected to a column of the sensor array.

[0051] In one aspect, a resistor is connected between a non-inverting input terminal of each of a plurality of row driver amplifiers and each switching unit SW1 or SW, and each of the switching units SW1 or SW is selectively coupled to the row driver amplifier via a non-inverting input terminal according to a first state or a second state of the switching unit SW1 or SW.

[0052] In an embodiment, the row driving unit 210 further includes a plurality of current sensing resistors R sen , where each current sensing resistor R sen coupled to the non-inverting input terminal of each of the plurality of row driver amplifiers, and one or more amplifying current sensing resistors R in FBIA sen The voltage across one or more of the terminals.

[0053] The readout device can reduce parasitic effects attributable to at least one of parasitic resistance of one or more connections or printed circuit board (PCB) lines from the sensor array and an offset voltage applied between input terminals of a row driver amplifier.

[0054] In an embodiment, the readout device can reduce crosstalk current effects associated with reading a resistive element of interest A in a selected row of a sensor array, where the crosstalk current effects are attributable to one or more neighboring resistive elements R arranged in the same column or a different row as the resistive element of interest A. um , where the adjacent resistor element R is read without being associated with the reading of the resistor element A of interest um .

[0055] The column scanning unit 230 may further include a plurality of feedback resistance elements, each of which is connected between an output terminal of a column operational amplifier and an inverting input terminal of the column operational amplifier, and each of the plurality of column operational amplifiers includes a grounded non-inverting input terminal.

[0056] In some embodiments, each column scanning unit 230 outputs an output voltage V via each corresponding column operational amplifier. outA multimeter can be used to measure the output voltage V of each of the column op amps. out .

[0057] The sensor array may have m column connections and n row connections, and each of the plurality of resistive elements is connected between a corresponding one of the m column connections and a corresponding one of the n row connections.

[0058] In one aspect, column scanning unit 230 also includes a plurality of adjacent resistor elements R that are not read in association with the reading of resistor element A of interest. um The connection of each adjacent resistor element R um Connected to the inverting input terminal of each column scanning unit 230 and a feedback resistance element corresponding to each column scanning unit 230 .

[0059] Voltage source V in The sensor array 220 may be configured to apply a voltage to one or more of the resistive elements via the one or more switching units SW1 or SW2 operating in the first state.

[0060] In an embodiment, the sensor array 220 may be used to sense microfluidic pressure, and each of the resistive elements has a minimum resistance of 10 ohms and a maximum resistance of 200 ohms.

[0061] The sensor array 220 may be a resistive sensor array suitable for use in small electronic devices to replicate the functionality of human skin.

[0062] When reading a resistor element A of interest, the plurality of adjacent resistor elements R associated with the resistor element A of interest may be read. um Each row achieves zero or negligible current.

[0063] The voltage drop across each resistive element of sensor array 220 may be adjusted in response to determined parasitic effects attributable to parasitic resistance of one or more connections or printed circuit board (PCB) lines from sensor array 220 or an offset voltage applied between input terminals of a row driver amplifier.

[0064] In an embodiment, the plurality of feedback instrumentation amplifiers (FBIA) may include an inverting input terminal and a non-inverting input terminal, wherein the non-inverting input terminal is connected to the first end of the first switching unit SW1 and the first current sensing resistor R sen The first end of the inverting input terminal is connected to the second end of the first switching unit SW1 and the first current sensing resistor R sen The second end of the first switching unit SW1 and the current sensing resistor R sen Connect in parallel.

[0065] A row of resistor elements may include at least one resistor element having a current sensing resistor R coupled to the current sensing resistor R sen and a first end of one end of the switching unit SW1 or SW and coupled to an adjacent resistor element R um one end of the second end.

[0066] The resistive elements of sensor array 220 may include one or more resistive elements configured to detect measurable levels of voltage, current, or resistance value.

[0067] Each of the plurality of row driver amplifiers may include a non-inverting input terminal connected to the switching unit SW1 or SW and grounded via a single resistor, wherein the non-inverting input terminal is selectively connected to a voltage source V based on a state of the connected switching unit SW1 or SW. in .

[0068] The output of each of the plurality of FBIAs may be connected to an inverting input terminal of each of the row driver amplifiers via a first resistor, and the inverting input terminal is further connected to the output of each of the row driver amplifiers via a second resistor, wherein the first resistor and the second resistor are connected in series between the output of each FBIA and the output of each row driver amplifier.

[0069] Figure 3A and Figure 3B are simplified circuit diagrams 300 and 310 illustrating zero potential method (ZPM) and DZCM circuit designs for one unmeasured resistor according to embodiments of the present disclosure.

[0070] To illustrate the properties of ZPM and DZCM, the present invention discloses simplified network configurations 300 and 310, which feature only one unmeasured resistor R um , to demonstrate the parasitic effects attributable to this single resistor. Figure 3 presents the circuit diagrams of simplified models of a) ZPM and b) DZCM, where all amplifiers are assumed to be ideal.

[0071] according to Figure 3A The simplified model 300 can be used to convert R um The current is derived as:

[0072] Equation 1a: I um–ZMP =(v os1 –v os2 ) / (R um +R par )

[0073] according to Figure 3B The simplified model 310 can be used to convert R um The current is derived as:

[0074] Equation 1b:

[0075] In the present invention, the current of the unmeasured resistor of the zero point module (ZPM) and the double zero current module (DZCM) is designated as I um-ZPM and I um-DZCM The expressions for these currents are provided in Equations 1a and 1b, respectively. The offset voltages for the row and column driver amplifiers are given by V os1 and V os2 In addition, the parasitic resistance of the row and column lines is represented by R par denoted by R sen The gain of the feedback input amplifier (FBIA) is represented by A f , and the current through the sense resistor is specified as I sen .

[0076] From Equation 1a of ZPM and Equation 1b of DZCM, we can see that due to the presence of R in the denominator sen (1+A f ) term, I calculated from Equation 1b um-DZCM Relatively smaller than I in Equation 1a um-ZPM .

[0077] An example embodiment for calculating the measurement error assumes that A f =1000, R sen =1.0W, R um =10.0W, R par =1.0W, and R a =R b =1.0kW, where V os1 =1.00mV and V os2 = -1.00 mV. Then, Equation 1a yields I for ZPM um-ZPM =0.18 mA, and Equation 1b for DZCM yields I um-DZCM = 0.0019 mA. In this example calculation, V os1 、V os2 and R par As a result, the negative feedback in the DZCM circuit reduces its parasitic current to 1% of the parasitic current in the ZPM circuit. Therefore, the DZCM minimizes the measurement error in low-value RSA to a great extent.

[0078] Figure 4 is a simplified circuit diagram 400 illustrating a DZCM circuit model of a 2×2 sensor array including parasitic effects and crosstalk current effects according to an embodiment of the present disclosure.

[0079] In order to evaluate the crosstalk current impact in DZCM, Figure 4 As shown, the 2×2 array is derived from the 4×4 array by further simplification. The reduced array network 400 includes V os1 、V os2 and R par Based on the previous discussion and Equations 1a and 1b, the adjacent unmeasured resistor R in the DZCM 21 and R 22 The crosstalk current 420 from R in DZCM represents only 1% of the crosstalk current in ZPM. 21 and R 22 The crosstalk current effect 420 is considered to be negligible and can be ignored. It is worth noting that when the following equation 2 is derived, Figure 4 R shown in 21 and R 22 Can be safely ignored.

[0080] based on Figure 4 From the simplified circuit diagram 400, the following equations can be derived:

[0081] Equation 2a: V a =V os21 +I f1 R par =V os21 +I 11 R par

[0082] Equation 2b: V b =V os11 +V in -I b R par =V os11 +V in -(I 11 +I 12 )R par

[0083] Equation 2c: V d =I f2 R par +V os22 =I 12 R par +V os22

[0084] Equation 2d: V b -V a =I 11 R 11

[0085] Equation 2e: V b -Vd =I 12 R 12

[0086] use Figure 5 Kirchhoff's laws are depicted in the circuit diagram 500 to check Figure 4 The DZCM network 400 presented in FIG.

[0087] To simplify the calculation, assume that R11 = R x , R12=R um And 10*R par <R um ≈R x After substituting equations 2d and 2e into equations 2a, 2b, and 2c, we obtain equation 3:

[0088] Equation 3a: I 11 (R x +2R par )+I 12 R par =V os11 +V in –V os21

[0089] Equation 3b: I 11 R par +I 12 (R um +2R par )=V os11 +V in –V os22

[0090] Equation 3 is a non-homogeneous linear equation R·I=V, and after several solution steps, V os12 The crosstalk current effect at is derived as:

[0091] Equation 4:

[0092] Due to R par < <R um ≈R x , so equation 4 can be simplified to:

[0093] Equation 5:

[0094] However, if we assume that R par < <R um ≈R x , then for the ZPM 2×2 array circuit model including parasitic and crosstalk effects, the following equation for the crosstalk current effect is derived:

[0095] Equation 6:

[0096] Obviously, Equation 5 shows similarity to Equation 6, except that the variables in Equation 6 are missing. Since there are no variables in Equation 5 Equation 5 therefore results in a lower error produced by Vos12 compared to Equation 6, thereby producing favorable results with respect to the DZCM array network.

[0097] Turning now to a description of various experiments used to evaluate embodiments of the present disclosure, some of these embodiments illustrate embodiments of the present disclosure in addition to those discussed above.

[0098] A number of experiments have been designed to evaluate the performance of ZPM and DZCM under optimal conditions. The experimental configuration is shown in Table 1.

[0099]

[0100] Table 1. Experimental configuration of DZCM with selected combinations

[0101] The measurement of an ideal single resistor from a multimeter is denoted as R id At the same time, the voltage of the output amplifier of the array resistor is measured by a multimeter as V out The resistor of interest, R, can be obtained using the following equation x Resistance value: R id With R x The measured percentage error between is estimated as follows:

[0102] Experiment (EXP) A analyzes the effect of the resistor R um fixed at its lower and upper limits (i.e., 1Ω and 200Ω, respectively) and R par and V os When set to zero, R x Effect on e% for arrays of various sizes.

[0103] EXP B analyzes the x Increase and R par and V os When it is zero, the array resistor R is not measured um Effect on e% in the simplest 2×2 array.

[0104] EXP C analyzes the situation when the array resistor R is not measured. um and R x Fixed at 1Ω(V in =10mV)、50Ω(V in =100mV), 200Ω(V in=1000mV) and the offset voltage V os When the parasitic resistance of the column and row (R parCol and R parRow ) on e%. As R um and R x The increase of V in The reason is to avoid crosstalk current effect. If V in Fixed at 10mV and R x If the resistance increases to 50Ω or 200Ω, the crosstalk current effect will exceed R x The array size is set to 6×6 and 12×12.

[0105] EXP D analyzes the situation when the array resistor R is not measured. um and R x Fixed to 1Ω(V in =10mV)、50Ω(V in =100mV), 200Ω(V in =1000mV) and R par When set to zero, V os Effect on e%. The array size is set to 6×6 and 12×12.

[0106] Experimental results of DZCM under ideal resistor conditions

[0107] Experiment A:

[0108] Fig. 6A and Figure 6B FIG. 1 is a diagram showing that, for DZCM and ZPM circuit designs according to an embodiment of the present disclosure, the resistor (R um ) are set to 200 ohms and 1 ohm respectively, the resistor of interest (R x ) for various sensor array sizes (S AR ) is a graph showing the influence of measurement error.

[0109] like Fig. 6A As shown, in R um =200Ω:

[0110] When R x When the R falls within the range of 1Ω to 10Ω, the measurement errors of DZCM and ZPM are found to be comparable. x Within this range, the additional feedback network of DZCM does not significantly improve the system performance.

[0111] like Figure 6B As shown, in R um =1Ω:

[0112] In the range of 1Ω to 10Ω R x In the range, the e% of DZCM is less than that of ZPM, indicating the advantage of DZCM feedback network in reducing crosstalk current.

[0113] In conclusion, Fig. 6A and Figure 6B shows that at 1Ω<R x <10Ω and R um =1Ω, the improvement of DZCM in reducing measurement error. That is, in low resistance RSA, DZCM can reduce measurement error.

[0114] Experiment B:

[0115] Figure 7 FIG. 1 is a diagram showing that, according to an embodiment of the present disclosure, for DZCM and ZPM circuit designs, the sensor array size (S AR ) is set to 2×2, the resistor of interest (R x ) for various untested resistors (R um )’s influence.

[0116] like Figure 7 As shown, at 1Ω <R x In the <10Ω range, the e% of DZCM is smaller or similar to that of ZPM.

[0117] Experiment C:

[0118] FIG. 8A to FIG. 8F FIG. 2 is a diagram showing the unmeasured resistor (Rx) when the resistor of interest (Rx) is set to 1 ohm, 50 ohm, and 200 ohm according to an embodiment of the present disclosure. um ), the parasitic resistance of both the row and column lines (R par ), the parasitic resistor of the column line (R parcol ) or the parasitic resistor of the row line (R parRow ) for various sensor array sizes (S AR ) is a graph showing the influence of measurement error.

[0119] like Fig. 8A , Figure 8B and Figure 8C As shown, when R parRow (parasitic resistance of the row line) changes from 0Ω to 3.5Ω and R um =R x =1Ω, 50Ω, 200Ω, ZPM's R x Error and R in DZCM x The error is the same.

[0120] When RparCol When the parasitic resistance of the column line changes from 0Ω to 3.5Ω, R um =R x =1Ω, 50Ω, 200Ω, if Fig.8D , Fig. 8E and Fig.8F As shown, the R x The error is higher than the R of DZCM x Error. Larger array sizes lead to larger error differences between ZPM and DZCM. This error difference increases with R parCol This is due to the presence of a negative feedback network in the DZCM, which effectively reduces the R par parasitic effects.

[0121] Experiment D:

[0122] 9A to 9F is a diagram showing the resistor of interest (R x ) is set to 1 ohm, 50 ohm, and 200 ohm unmeasured resistors (R um ), the offset voltage (Vos C ) or the offset voltage of the row amplifier (Vos R ) for various sensor array sizes (S AR ) is a graph showing the influence of measurement error.

[0123] To analyze the system performance in terms of offset voltage, the error variation is preferred over the absolute error. As discussed in Experiment A, the absolute error can be eliminated by manual operation. On the other hand, as v osC (column amplifier offset voltage) and v osR (the offset voltage of the row amplifier) ​​changes, the fluctuation of e% is non-zero. This instability in the measurement error is usually caused by temperature drift and process variations of the amplifier chip.

[0124] There are offset voltages across rows and columns in the RSA. osC In the experiment of the effect, v osR Keep constant at zero, v osC The voltage is changed from -3mV to 3mV in 1mV steps. Similarly, for evaluating v osR The second study of the impact, v osC Fixed to zero, v osR The offset voltage v changes from -3mV to 3mV in 1mV steps. osR and v osC is applied to the positive inputs of all row and column amplifiers, labeled v os1 and vos2 (See Figure 3A and Figure 3B ). Error variation is defined as the difference in measurement error associated with the experimental conditions.

[0125] like Figure 9A-9E As shown, when v osC and v osR When changing from -3mV to +3mV in 1mV steps, DZCM (curve with solid dots) has lower R than ZPM (curve with open dots) in all array sizes. x This shows that DZCM can eliminate the error caused by the row / column amplifier v osR and v osC Such improvements can be demonstrated in the above equations (5) and (1b) respectively. The DZCM equation (5) has one less term than the ZPM equation (6). This is because, according to equation (5), A in the DZCM feedback network f The presence of helps to reduce the impact of offset voltage on error measurements.

[0126] like Fig.9F As shown, when v osR When changing from -3mV to +3mV in 1mV steps, DZCM has larger R than ZPM in all array sizes. x The error changes. This indicates that DZCM is not suitable for high-value RSA. However, the error gap between DZCM and ZPM decreases as the array size increases. This means that DZCM will have better performance when high-value RSA has a larger array size.

[0127] These properties are shown in Table 2:

[0128]

[0129] Table 2: In S AR =6×6 and 12×12 cases v osR 、v osC R x Error change

[0130] Fig.10 It is shown that the Figure 1-Figure 5 A block diagram of a technical architecture 1000 of a sensing device and / or a control device corresponding to the sensing device to perform readout of a sensor array is provided in some or all of a circuit schematic.

[0131] For example, the control device may include a server, a cloud computing device, a wearable device, etc., and may receive data from and / or send data to another device such as a sensing device. The sensing device may include a plurality of sensor elements (e.g., an array of sensor elements), each of which is configured to measure voltage information. The sensing device may further include an integrated readout circuit, such as described above with respect to Figure 2 An example DZCM circuit design is described. The sensing device can utilize a variety of sensor technologies, such as charge coupled device (CCD) technology and complementary metal oxide semiconductor (CMOS) technology.

[0132] The technology architecture includes a processor 1022 (which may be referred to as a central processor unit or CPU) that communicates with memory devices including secondary storage 1024 (such as a disk drive), read-only memory (ROM) 1026, and random access memory (RAM) 1028. The processor 1022 may be implemented as one or more CPU chips. The technology architecture may also include input / output (I / O) devices 1030 and network connection devices 1032.

[0133] Secondary storage 1024 is typically comprised of one or more disk drives or tape drives and is used for non-volatile storage of data and as an overflow data storage device if RAM 1028 is not large enough to hold all working data. Secondary storage 1024 may be used to store programs that are loaded into RAM 1028 when those programs are selected for execution.

[0134] In this embodiment, the secondary storage 1024 has a command processing component 1024a, which includes non-transitory instructions that are operated by the processor 1022 to perform various operations of the method of the present disclosure. ROM 1026 is used to store instructions and possible data that are read during program execution. Secondary storage 1024, RAM 1028, and / or ROM 1026 may be referred to as computer-readable storage media and / or non-transitory computer-readable media in some contexts.

[0135] I / O devices 1030 may include a printer, a video monitor, a liquid crystal display (LCD), a plasma display, a touch screen display, a keyboard, a keypad, switches, a dial, a mouse, a trackball, a voice recognizer, a card reader, a paper tape reader, one or more different sensors such as touch sensors, force sensors, motion sensors, temperature sensors, and biosensors, or other well-known input devices.

[0136] The processor 1022 executes instructions, codes, computer programs, scripts that it accesses from a hard disk, floppy disk, optical disk (these various disk-based systems can all be considered secondary storage 1024), flash drive, ROM 1026, RAM 1028, or network connection device 1032. Although only one processor 1022 is shown, multiple processors may be present. Thus, although instructions may be discussed as being executed by a processor, the instructions may be executed by one or more processors simultaneously, serially, or otherwise.

[0137] Although the technical architecture is described with reference to a single control device or sensing device, it should be understood that the technical architecture can be formed by two or more devices that communicate with each other to collaborate to perform tasks. For example, but not by way of limitation, the application can be divided in a manner that allows concurrent and / or parallel processing of the instructions of the application. Alternatively, the data processed by the application can be divided in a manner that allows different parts of the data set to be processed concurrently and / or in parallel by two or more devices. In an embodiment, the technical architecture 1000 can use virtualization software to provide the functions of multiple servers that are not directly bound to multiple devices in the technical architecture 1000. In an embodiment, the functions disclosed above can be provided by executing an application and / or multiple applications in a cloud computing environment. Cloud computing can include providing computing services via a network connection using dynamically scalable computing resources. The cloud computing environment can be established by an enterprise and / or can be rented from a third-party provider as needed.

[0138] By programming and / or loading executable instructions onto the technical architecture, at least one of the CPU 1022, RAM 1028, and ROM 1026 is changed, thereby partially transforming the technical architecture into a special-purpose machine or device having novel functions taught by the present disclosure. The fields of electrical engineering and software engineering are based on the fact that functions that can be implemented by loading executable software into a computer can be converted into hardware implementations through well-known design rules.

[0139] Although the foregoing description has described exemplary embodiments, those skilled in the art will appreciate that many variations of the embodiments are possible within the scope and spirit of the invention.

Claims

1. A reading device, comprising: a sensor array comprising a plurality of resistive elements; and A row driving unit electrically couples a voltage source to a plurality of rows of resistor elements of the sensor array for driving the voltage source to a row of resistor elements among the plurality of rows of resistor elements, wherein the row driving unit comprises a plurality of switching units, a plurality of row driving amplifiers, and a plurality of feedback instrumentation amplifiers (FBIAs), wherein each of the switching units performs a switching operation and is selectively electrically coupled to each of the row driving amplifiers, and each of the row driving amplifiers is coupled to each of the FBIAs.

2. A read-out device according to claim 1, wherein a resistor is electrically coupled between a non-inverting input terminal of each of the plurality of row driver amplifiers and each switching unit, and each of the switching units is selectively electrically coupled to the row driver amplifier via the non-inverting input terminal according to a first state or a second state of the switching unit.

3. A readout device according to claim 1 or 2, wherein the row driving unit further includes a plurality of current sensing resistors, wherein each current sensing resistor is electrically coupled to a non-inverting input terminal of each of the plurality of row driving amplifiers, and one or more of the FBIAs amplify the voltage across one or more of the current sensing resistors.

4. A readout device according to any of the preceding claims, wherein parasitic effects attributable to at least one of parasitic resistance of one or more connections or printed circuit board (PCB) lines from the sensor array and an offset voltage applied between the input terminals of the row driver amplifier are reduced.

5. A readout device according to any of the preceding claims, wherein crosstalk current effects associated with reading a resistor element of interest in a selected row of the sensor array are reduced, wherein the crosstalk current effects are attributable to one or more adjacent resistor elements arranged in the same column or different row as the resistor element of interest, wherein the adjacent resistor elements are not read in association with the reading of the resistor element of interest.

6. The readout device according to any one of the preceding claims, further comprising a column scanning unit for detecting at least one voltage signal of a resistance element among the plurality of resistance elements, wherein the column scanning unit comprises a plurality of column operational amplifiers and a plurality of feedback resistance elements, wherein each of the column operational amplifiers is electrically coupled to one of the plurality of columns of the sensor array, wherein each feedback resistance element is electrically coupled between an output terminal of the column operational amplifier and an inverting input terminal of the column operational amplifier, and each of the plurality of column operational amplifiers comprises a non-inverting input terminal connected to ground.

7. A readout device according to any of the preceding claims, wherein the sensor array has m column connections and n row connections, and each of the plurality of resistor elements is connected between a corresponding one of the m column connections and a corresponding one of the n row connections.

8. A read-out device according to any of the preceding claims, wherein the column scanning unit further comprises a plurality of adjacent resistance elements, which are read independently of the reading of the resistance element of interest, wherein each adjacent resistance element is electrically coupled to an inverting input terminal of each column scanning unit and a feedback resistance element corresponding to each column scanning unit.

9. A readout device according to any of the preceding claims, wherein the voltage source is configured to apply a voltage to one or more of the resistive elements of the sensor array via one or more switching units operated in a first state.

10. A readout device according to any one of the preceding claims, wherein the sensor array is used to sense microfluidic pressure and each of the resistive elements has a minimum resistance of 10 ohms and a maximum resistance of 200 ohms.

11. A readout device according to any one of the preceding claims, wherein the sensor array is a resistive sensor array suitable for use in small-scale electronic devices replicating the function of human skin.

12. A readout device according to any one of the preceding claims, wherein when reading a resistive element of interest, zero or negligible current is achieved through each row of a plurality of adjacent resistive elements associated with the resistive element of interest.

13. A readout device according to any of the preceding claims, wherein the voltage drop across each of the resistive elements of the sensor array is adjusted in response to determined parasitic effects attributable to parasitic resistance of one or more connections or printed circuit board (PCB) lines from the sensor array or an offset voltage applied between the input terminals of the row driver amplifier.

14. A readout device according to any of the preceding claims, wherein at least one of the plurality of feedback instrumentation amplifiers (FBIA) comprises an inverting input terminal and a non-inverting input terminal, wherein the non-inverting input terminal is electrically coupled to a first end of a first switching unit and a first end of a first current sensing resistor, the inverting input terminal is electrically coupled to a second end of the first switching unit and a second end of the first current sensing resistor, and the first switching unit and the current sensing resistor are electrically coupled in parallel.

15. A readout device according to any of the preceding claims, wherein the row of resistor elements includes at least one resistor element, the at least one resistor element having a first end electrically coupled to one end of the current sensing resistor and one end of the switching unit and a second end electrically coupled to one end of an adjacent resistor element.

16. A readout device according to any preceding claim, wherein the resistive elements of the sensor array comprise one or more resistive elements configured to detect a measurable level of voltage, current or resistance value.

17. A readout device according to any of the preceding claims, wherein each of the plurality of row driver amplifiers comprises a non-inverting input terminal electrically coupled to a switching unit and electrically coupled to ground via a single resistor, wherein the non-inverting input terminal is selectively electrically coupled to the voltage source based on a state of the electrically coupled switching unit.

18. A readout device according to any of the preceding claims, wherein the output of each of the plurality of FBIAs is electrically coupled to the inverting input terminal of each of the row driver amplifiers via a first resistor, and the inverting input terminal is further electrically coupled to the output of each of the row driver amplifiers via a second resistor, wherein the first resistor and the second resistor are electrically coupled in series between the output of each FBIA and the output of each row driver amplifier.

19. A non-transitory computer readable medium comprising executable instructions that, when executed by one or more computers, cause the one or more computers to measure voltage values ​​of resistive elements of a sensor array using a readout device, the readout device comprising: a sensor array comprising a plurality of resistive elements arranged in a plurality of rows and columns; and A row driving unit electrically couples a plurality of rows of resistor elements of the sensor array to a voltage source for driving the voltage source to a row of resistor elements among the plurality of rows of resistor elements, wherein the row driving unit comprises a plurality of switching units, a plurality of row driving amplifiers, and a plurality of feedback instrumentation amplifiers (FBIAs), wherein each of the plurality of switching units performs a switching operation and is selectively coupled to each of the plurality of row driving amplifiers, and each of the row driving amplifiers is coupled to each of the plurality of FBIAs.

20. A method for measuring a voltage value of a resistance element using a readout device, the method comprising: Arranging a plurality of resistive elements of a sensor array; electrically connecting a plurality of rows of resistor elements of the sensor array to a voltage source via a row driving unit for driving the voltage source to a row of resistor elements among the plurality of rows of resistor elements, wherein the row driving unit comprises a plurality of switching units, a plurality of row driving amplifiers, and a plurality of feedback instrumentation amplifiers (FBIAs), wherein each of the switching units is selectively coupled to each of the plurality of row driving amplifiers, and each of the row driving amplifiers is coupled to each of the plurality of FBIAs; as well as A switching operation is performed via the plurality of switching units.

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