Ranging system and method for reducing transition effects in multi-range material measurements

Abstract

To provide a ranging system and method for reducing transition effects in suitable multi-range material measurements. [Solution] The measurement system includes a gain chain configured to amplify an analog input signal, a range selector configured to select the gain between the analog input signal and multiple analog-to-digital converter (ADC) outputs from multiple ADCs, each ADC output having a path, the gain of each output path consisting of multiple gain stages in the gain chain, and a mixer configured to combine the multiple ADC outputs into a single mixed output.

Description

[Technical Field]

[0001] (Cross-reference of related applications) This application claims priority to U.S. Provisional Patent Application No. 63 / 016,747, “Advanced Analog-to-Digital Conversion Systems and Methods,” filed April 28, 2020, to Fortney; U.S. Provisional Patent Application No. 63 / 034,052, “Advanced Digital-to-Analog Signal Generation Systems and Methods,” filed June 3, 2020, to Fortney; and U.S. Provisional Patent Application No. 63 / 057,745, “Synchronous Source Measure Systems and Methods,” filed July 28, 2020, each of which is incorporated herein by reference as a whole.

[0002] This disclosure relates to measurement systems and methods. More specifically, it relates to avoiding glitches or errors caused by variations in the ranging of electronic equipment used in measurements. More generally, it relates to electronic equipment, analytical instruments, software, and infrastructure for signal supply and signal measurement. This disclosure also relates to systems for measuring signals for material and device characterization and other applications under challenging experimental conditions that may cause high levels of noise and interference. [Background technology]

[0003] Measurements of material and device properties (e.g., electron transport properties such as hole density, mobility, and carrier concentration) often require continuous measurements over several decades or orders of magnitude changes in the properties being measured. Capturing this requires switching between one set of analytical electronics, each configured for different ranges (e.g., several decades or orders of magnitude) in the properties being measured. This switching can cause glitches and / or gaps in the measurement signal. This can also disrupt the data acquisition process in other ways, such as by causing transient events that can impair the measurement.

[0004] Analog-to-digital converters (ADCs) play a crucial role in electronic devices that amplify, filter, sample, and digitize measurement signals in these measurement systems. Therefore, ADC signal processing must be carefully configured for operating conditions, including the range of properties being measured. However, carefully configuring an ADC system for one range is likely to make it unsuitable for others. This can lead to errors, especially when properties vary across the range. Selective amplification can address these errors. However, amplifiers introduce their own errors. These errors stem from amplifier noise, offset, gain error, and phase mismatch. Furthermore, carefully configuring gain across several ranges requires the flexibility that most amplification systems lack. Small signals require high gain to increase resolution and noise performance. As the signal grows throughout the measurement process, that same high gain can saturate the ADC. This can cause distortion and signal loss.

[0005] To increase flexibility in configuring the gain, amplifier stages can be switched on and off, or on and off the signal chain. At any given time, the amplifier that is switched on is configured for the current signal range. When the signal enters a different range, the system switches to a different amplifier chain configured for the new range. However, glitching and discontinuities in the measurement often appear during the transition.

[0006] Figure 1 shows the effect in a measurement that is ranged in the conventional way. Specifically, Figure 1 shows the transition of the measurement signal t TR The conventional ranging data 104 over the discontinuity D that occurs when increasing from a lower range r1 to a higher range r2 is shown. Figure 2 shows an example of a conventional ranging setting 120 that can cause the discontinuity D shown in Figure 1. The conventional ranging setting 120 includes two gain chains A and B. Gain chain A is dedicated to the lower range r1 (Figure 1) and is configured for that purpose. Specifically, amplifier G A The gains of both ADC A and ADC A are configured for the lower range r1. Gain chain B is dedicated to the higher range r2 (Figure 2) and is configured for that purpose. This is amplifier G B This means that the gain of ADC B is configured for r2.

[0007] When the measured signal is small (i.e., within a lower range r1), the channel selection component 122 of the ranging setting 120 selects gain chain A. As the measured signal increases toward a higher range r2, t TR When transitioning between ranges t, the channel selection component 122 engages the electronic gain chain B. In this way, the channel selection component 122 attempts to ensure that the measurement system has gains configured over two different ranges. However, as schematically shown in Figure 1, transition t TRcan introduce discontinuity D in the measurement data. This is because the switching between gain chains A and B can introduce transient signals, noise, or glitches resulting from the "warm-up" of the equipment dedicated to measuring over the range of the transition destination or from the start of use.

[0008] Discontinuity D results in two types of ranging errors. These errors occur when two ranges (e.g., r1 and r2) have different configured amplifier profiles (A and B respectively). In the first type of error, the amplifier profile mismatch causes unwanted amplitude discontinuities or fluctuations (ΔV) in the measured output voltage. In the second type, the temporal data discontinuity, the data flow can be interrupted during the transition between ranges. In FIG. 1, this appears as a data gap during the period from t TR to t B The temporal data discontinuity occurs when the changing range is associated with the "warm-up" or a new electronic device being engaged, specifically, the amplifier associated with profile B. Collecting data is inaccurate or impossible until these transient events dissipate. Transient events from the cool-down or stop of the amplifier associated with amplifier profile A can also cause delays or glitches in the measurement system.

[0009] Configuring settings such as 120 to eliminate discontinuity D is difficult or impossible. The configuration is limited by the simplicity and lack of variability of the components (G A [[ID=?]]、ADC A、G B and ADC B). Therefore, there is a significant need for a new and improved solution to provide a robust and high-quality low-noise source or measurement signal even when the measurement signal varies over several decades or orders of magnitude. There is a significant need for a flexible solution to reduce the discontinuities as shown in FIG. 1 or to provide a smoother transition between ranges that eliminates them. SUMMARY OF THE INVENTION MEANS FOR SOLVING THE PROBLEM It should be noted that there seems to be an unclear part in the original text where "G 、ADC A、G " is presented. This might be a formatting or content error in the original. The translation is done based on the best understanding of the available text.

[0010] Aspects of the present disclosure include a gain chain configured to amplify an analog input signal, and a range selector configured to select a gain between the analog input signal and a plurality of analog-to-digital converter (ADC) outputs from a plurality of ADCs, wherein each ADC output has a path, and the gain of each output path can be composed of a plurality of gain stages in the gain chain, and a mixer configured to combine the plurality of ADC outputs into a single mixed output, including a measurement system.

[0011] The plurality of ADCs may include a first ADC and a second ADC. The step of combining the plurality of ADC outputs may be performed according to mixed output = αE first +(1-α)E second where E first may be the output of the first ADC, E second may be the output of the second ADC, and α may be a mixing parameter that varies from 1 to zero. The system may include two or more ADCs. The first part of the gain chain may be connected to the first of the plurality of ADCs, and the second part of the gain chain may be connected to the second of the plurality of ADCs. The range selector may select the gain for the first of the plurality of ADCs from the first part of the gain chain and the gain for the second of the plurality of ADCs from the second part of the gain chain. Each gain stage in the gain chain may be connected to each of the plurality of ADCs via one or more switch banks. The range selector may select the first part of the shared gain stage for the first of the plurality of ADCs and the second part of the shared gain stage for the second of the plurality of ADCs by setting switches in one or more switch banks. The range selector may include a first and a second multiplexer. The first multiplexer may select the first part of the shared gain stage. The second multiplexer may select the second part of the shared gain stage.

[0012] The selection of the first part of the common gain stage may include steps of configuring the gain for the first of the plurality of ADCs, and the selection of the second part of the common gain stage may include steps of configuring the gain for the second of the plurality of ADCs. The steps of configuring the gains for the first and second of the plurality of ADCs may include steps of configuring the gain according to at least one range of the input signal. The mixer may be configured to select the output from the first ADC as a single mixed output when the input signal may be within the first range. The mixer may be configured to select the output from the second ADC as a single mixed output when the input signal may be within the second range. The mixer may be configured to select a mixture of the outputs from the first and second ADCs as a single mixed output when the input signal may be between the first and second ranges.

[0013] The system may maintain the second ADC online during the first transition period when the input signal may be within the first range. The system may maintain the first ADC online during the second period when the input signal may be within the second range. The range selector may be configured to configure the gain for at least one of the first ADC and the second ADC based on the expected range of the input signal. During the hysteresis period, the system may maintain the first ADC offline. The system may maintain the second ADC online. The system may maintain the gain of the second ADC constant. The hysteresis period may be between the first transition period and the second transition period.

[0014] Multiple ADC output paths may comprise two ADC output paths, which may be configured independently as high-range and low-range paths. The low-range path may have a first gain for converting the analog input signal. The high-range path may have a second gain for converting the analog input signal. The second gain may be lower than the first gain. The paths may include a mixing device configured to combine lower-range outputs with higher-range outputs. The system may include a device configured to vary the amount of gain combined from the low-range and high-range paths. The high-range path may be connected to a first gain chain, and the low-range path may be connected to a second gain chain. The system may include a selector for selecting the gain stage of the first gain chain for the first gain and the gain stage of the second gain chain for the second gain. The first and second gains may each have gain stages in a gain chain common to the low-range and high-range paths. The gains of each output path may be substantially identical. The mixer may average the output from each path to reduce noise in a single output.

[0015] Aspects of the present disclosure may further include the steps of amplifying an analog input signal using a gain chain, selecting a gain between the analog input signal and a plurality of analog-to-digital converter (ADC) outputs from a plurality of ADCs, wherein each ADC output has a path, and the gain of each output path may consist of a gain stage in the gain chain, and combining the plurality of ADC outputs into a single mixed output.

[0016] The first part of the gain chain may be connected to a first of several ADCs, and the second part of the gain chain may be connected to a second of several ADCs. Each gain stage in the gain chain may be connected to each of several ADCs via one or more switch banks. The method may further include the step of configuring two ADC output paths independently as high-range and low-range paths. The method may include the step of applying a first gain from the low-range path to convert the analog input signal. The method may include the step of applying a second gain from the high-range path to convert the analog input signal, the second gain may be lower than the first gain. The method may include the step of combining the lower-range output with the higher-range output. The method may include the step of varying the amount of gain combined from the high-range and low-range paths. The present invention provides, for example, the following: (Item 1) A measurement system, A gain chain configured to amplify an analog input signal, A range selector configured to select the gain between the analog input signal and a plurality of ADC outputs from a plurality of analog-to-digital converters (ADCs), wherein each ADC output has a path, and the gain of each output path is comprised of a plurality of gain stages in the gain chain. A mixer configured to combine the aforementioned multiple ADC outputs into a single mixed output, A measurement system equipped with the following features. (Item 2) The plurality of ADCs comprises a first ADC and a second ADC, Combining the aforementioned multiple ADC outputs means Mixed output = αE first +(1-α)E second It will be carried out in accordance with, During the ceremony, E first This is the output of the first ADC, E secondThis is the output of the second ADC, α is a mixture parameter that varies from 1 to 0. The system described in item 1. (Item 3) A system comprising two or more ADCs, as described in either item 1 or 2. (Item 4) The first portion of the gain chain is connected to the first of the plurality of ADCs, and the second portion of the gain chain is connected to the second of the plurality of ADCs. The aforementioned plurality of ADCs comprises at least two types of ADCs. A system that is at least one of the systems described in any one of items 1-3. (Item 5) The system according to item 4, wherein the range selector selects the gain for a first of the plurality of ADCs from a first part of the gain chain and the gain for a second of the plurality of ADCs from a second part of the gain chain. (Item 6) The system according to any one of items 1-5, wherein each of the gain stages in the gain chain is connected to each of the plurality of ADCs via one or more switch banks. (Item 7) The system according to item 6, wherein the range selector selects a first portion of the shared gain stage with respect to a first of the plurality of ADCs and a second portion of the shared gain stage with respect to a second of the plurality of ADCs by setting a switch in one or more switch banks. (Item 8) The range selector comprises first and second multiplexers, The first multiplexer selects a first portion of the shared gain stage, and the second multiplexer selects a second portion of the shared gain stage. The system described in item 6. (Item 9) The system according to item 8, wherein the selection of a first portion of the shared gain stage includes configuring the gain for a first of the plurality of ADCs, and the selection of a second portion of the shared gain stage includes configuring the gain for a second of the plurality of ADCs. (Item 10) The system according to item 9, wherein configuring the gains for the first and second of the plurality of ADCs includes configuring the gains according to at least one range of the input signal. (Item 11) The aforementioned mixer is, When the input signal is within a first range, the output from the first ADC is selected as the single mixed output, When the input signal is within the second range, the output from the second ADC is selected as the single mixed output. When the input signal is between the first and second ranges, a mixture of the outputs from the first and second ADCs is selected as the single mixed output. A system configured to perform any one of items 1-10. (Item 12) The aforementioned system, When the input signal is within the first range, the second ADC is kept online during the first transition period. When the input signal is within the second range, the first ADC is kept online during the second cycle. The system described in item 11. (Item 13) The system according to item 12, wherein the range selector is configured to configure the gain for at least one of the first ADC and the second ADC based on the expected range of the input signal. (Item 14) During the hysteresis period, the system Keep the first ADC offline, Keep the aforementioned second ADC online, Maintaining a constant gain for the second ADC, The system described in item 12. (Item 15) The system according to item 14, wherein the hysteresis period is between the first transition period and the second transition period. (Item 16) The aforementioned multiple ADC output paths are Two ADC output paths, one for high range and one for low range, which can be configured independently: The low-range path has a first gain for converting the analog input signal, The high-range path has a second gain for converting the analog input signal, the second gain being lower than the first gain. Two ADC output paths, A mixing device configured to combine an output in a lower range with an output in a higher range, A device configured to vary the amount of gain combined from the low-range path and the high-range path. A system comprising any one of items 1-15. (Item 17) The system according to item 16, wherein the high-range path is connected to a first gain chain, and the low-range path is connected to a second gain chain. (Item 18) The system according to item 16, further comprising a selector for selecting a gain stage of the first gain chain with respect to the first gain and a gain stage of the second gain chain with respect to the second gain. (Item 19) The system according to item 16, wherein the first and second gains each comprise a gain stage in a gain chain common to the low-range path and the high-range path. (Item 20) The gains of each output path are substantially the same. The mixer averages the outputs from each path and reduces noise in the single output. A system described in any one of items 1-19. (Item 21) It is a method, Amplifying an analog input signal using a gain chain, The process involves selecting the gain between the analog input signal and multiple ADC outputs from multiple analog-to-digital converters (ADCs), wherein each ADC output has a path, and the gain of each output path is comprised of gain stages in the gain chain. The above multiple ADC outputs are combined into a single mixed output. Methods that include... (Item 22) The method according to item 21, wherein the first portion of the gain chain is connected to a first of the plurality of ADCs, and the second portion of the gain chain is connected to a second of the plurality of ADCs. (Item 23) The method according to any one of items 21 and 22, wherein each gain stage in the gain chain is connected to each of the plurality of ADCs via one or more switch banks. (Item 24) The two ADC output paths are configured independently as a high-range path and a low-range path, Applying the first gain from the low-range path to convert the analog input signal, The process involves applying a second gain from the aforementioned high-range path to convert the analog input signal, wherein the second gain is lower than the first gain. Combining an output in a lower range than the aforementioned with an output in a higher range, The amount of gain combined from the high-range path and the low-range path is varied. The method described in any one of items 21-23, further including the method described in any one of items 21-23. [Brief explanation of the drawing]

[0017] [Figure 1] Figure 1 shows the effect of range transitions on data collected by a typical measurement system without seamless ranging capabilities.

[0018] [Figure 2] Figure 2 shows an example of a conventional ranging setting 120 that can cause the discontinuity D shown in Figure 1.

[0019] [Figure 3] Figure 3 compares a voltage measurement with seamless ranging 302 with the same measurement performed with a conventional setting 104 (from Figure 1) that lacks seamless ranging capability.

[0020] [Figure 4] Figure 4 shows one modified example 400 that implements seamless ranging via a double amplification chain.

[0021] [Figure 5] Figure 5 shows another exemplary amplification chain 500 according to an aspect of this disclosure.

[0022] [Figure 6A] Figure 6A provides a schematic embodiment of the automatic ranging algorithm 600 according to an aspect of this disclosure.

[0023] [Figure 6B] Figure 6B shows the measurement data corresponding to the automatic ranging algorithm 600.

[0024] [Figure 6C] Figure 6C shows algorithm 600 in flowchart form.

[0025] [Figure 6D] Figure 6D shows another automatic ranging algorithm 620 in flowchart form.

[0026] [Figure 7A] Figure 7A shows another modification 700, which shares a gain stage while using multiple ADCs (i.e., ADC A 708a and ADC B 708b), according to aspects of the present disclosure.

[0027] [Figure 7B] Figure 7B shows that the measurement signal 750a of the modified example 700 exhibits a discontinuity in magnitude 752 during the r1 / r2 transition in tTR.

[0028] [Figure 8] Figure 8 shows another modification 800, according to aspects of this disclosure, in which a preamplifier 804a precedes the gain chain 700c and / or a preamplifier 804b in one of the two paths.

[0029] [Figure 9] Figure 9 shows an interpolation algorithm 910 that is directed to eliminate or reduce discontinuities 752 according to the aspects of this disclosure.

[0030] [Figure 10A] Figure 10A shows a generalized variation of gain selection that may be used in accordance with this disclosure.

[0031] [Figure 10B] Figure 10B shows an exemplary gain path (gain path A) that can be created using Modification 1000.

[0032] [Figure 10C] Figure 10C shows another gain path (gain path B) for Modification 1000, including two variations, namely high-range and low-range variations.

[0033] [Figure 11] Figure 11 shows another modification 1100, which includes variable gain selection by gain stage selectors 1116a-1116n, according to aspects of the present disclosure.

[0034] [Figure 12A]Figure 12A is a schematic diagram of an exemplary mixing and automatic ranging algorithm 1200, which can be implemented by range mixers 410, 510, 710, 1010, and 1110.

[0035] [Figure 12B] Figure 12B shows an asymmetric automatic ranging algorithm 1250, which can be implemented by range mixers 410, 510, 710, 1010, and 1110.

[0036] [Figure 13A] Figure 13A shows a flowchart 1300 representing a range change prediction algorithm 1300 that can be implemented by range mixers 410, 510, 710, 1010, and 1110 when implementing the algorithms disclosed herein (e.g., 600, 620, 910, 1200, and 1250).

[0037] [Figure 13B] Figure 13B shows another part of flowchart 1300.

[0038] [Figure 13C] Figure 13C shows another part of flowchart 1300.

[0039] [Figure 14-1] Figure 14 shows an exemplary implementation of the range-mixed algorithm 1400. [Figure 14-2] Figure 14 shows an exemplary implementation of the range-mixed algorithm 1400.

[0040] [Figure 15] Figure 15 illustrates a measurement signal chain 1500 between an exemplary head unit 1550 and an exemplary measurement pod 1560, which may use variations 400, 500, 700, 800, 1000, 1100 and algorithms 600, 620, 910, 1200, 1250, 1300, and 1400.

[0041] [Figure 16] Figure 16 shows another exemplary modification 1600, according to aspects of the present disclosure, in which the head unit 1550 may have six channels capable of supporting three measurement type pods 1560a and three source type pods 1560b. [Modes for carrying out the invention]

[0042] Detailed explanation This disclosure introduces systems and methods that can be adapted to measurements across a wide dynamic range with relatively low error, noise, or glitching. Here, “glitching” refers to unintended irregularities or inconsistencies that may adversely affect the measurement or operation. The modifications disclosed herein accomplish this in several different ways. One method is to configure separate and dynamic gain chains with respect to separate ranges. Another is to combine separate ranges by mixing gain profiles with respect to the ranges. Yet another is to introduce a shared gain stage that can be dynamically assigned to separate ranges. These and further methods are generally referred to herein as “seamless ranging.” They are discussed in more detail below.

[0043] Figure 3 compares a voltage measurement with seamless ranging 302 according to this disclosure with the same measurement performed with a conventional setting 104 that lacks seamless ranging capability. Figure 3 shows discontinuities D in the measurement data 104 over the range transition Δt. This is because different sets of devices with different measurement profiles (e.g., accuracy, gain, etc.) are used to measure data in ranges r1 and r2. As will be discussed, switching between ranges r1 and r2 in system 120 may involve transient signals, noise, or glitches resulting from the “warm-up” or initial use of the instrument dedicated to measuring over the transition range (r2).

[0044] Figure 3 also illustrates how the transition Δt can be smoothed by the seamless ranging capability described herein (continuous ranging measurement data 302). This smoothing effect is represented in Figure 3 as avoidance of discontinuity D by the continuous ranging data 302. Although only two exemplary ranges r1 and r2 are discussed in the context of Figure 3, it should be understood that the continuous ranging technique can be applied to any suitable number of ranges related to a particular measurement. For example, the number of ranges may be three, four, or more in some cases. In each of these cases, continuous ranging can be configured to ensure a smooth transition between each range change, regardless of the direction of the range change (i.e., whether the range change involves an increase as shown in Figure 3 or a decrease in the measurement (not shown)).

[0045] Continuous ranging addresses two ranges r1 and r2 using separate signal amplification / gain chains that can be applied independently and / or in parallel. As an example, a specific implementation will be discussed below in the context of Figures 4 and 5. Addressing each range r1 and r2 separately and / or in parallel is based on the fact that data is collected by active amplification changes, and inactive or "cold" ranges (i.e., ranges not currently employed in the measurement, e.g., t) are not used. <t TR The range r² or t > t when this is true. TRThis allows for the configuration of amplification chains for range r1) when the range is active. Keeping amplification chains for inactive or cold ranges online in parallel with active range measurements can avoid starting transients when the inactive range is finally engaged. This also allows for "range mixing," where range-specific gain chains are applied in combination to facilitate a smooth transition of data over the transition Δt from range r1 to r2 (and vice versa). That is, amplification chains from both ranges can be applied simultaneously to smooth the data over the range transition Δt. This can be done, for example, via a software mixer and / or then smoothly transition from r1 to r2 and vice versa.

[0046] Figure 4 shows one modification 400 that implements seamless ranging via a dual amplification chain. As shown in Figure 4, the lower gain chain 402 (i.e., the gain chain with lower amplification) and the higher gain chain 404 (i.e., the gain chain with higher amplification) are identical except that 1) they use different ADCs (408a and 408b, respectively) and 2) an additional amplifier 406 in the higher gain chain 404, which gives it a higher gain than the lower gain chain 402. The outputs from ADCs 408a and 408b are combined by a mixer 410 and used in the acquisition routine of the measurement pod 104 for ranging measurements. In chain 400, the combinations can be weighted by a coefficient α. The coefficient α can be dynamically selected to ensure a smooth transition over the ranging transition Δt (e.g., using range mixing to avoid the discontinuity D in Figure 3). The coefficient α can be set by the user, but it is often set by a ranging algorithm (e.g., algorithms 600, 650, 910, 1200, 1250, 1300, and 1400, which are discussed in more detail below).

[0047] Figure 5 shows another exemplary amplification chain 500 used in seamless ranging. Chain 500 includes a lower-gain section 502 and a higher-gain section 504, which are identical except that 1) they are different ADCs (508a and 508b, respectively), 2) an additional amplifier 506 in the higher-gain section 504 which gives a higher gain than the lower-gain section 502, and 3) the lower-gain section 502 and the higher-gain section 504 are connected to a gain stage 512 via mux 514a and 514b, respectively.

[0048] As shown in Figure 5, the amplification supplied from gain stages 512a and 512b to the lower and higher gain sections 502 and 504 can be selected via mux 514a and 514b, respectively. Thus, chain 500 may use fewer dedicated amplifiers than chain 400 and provide combinations to mixer 510. Using the same gain stages 512a and 512b (and amplifiers) for the lower and higher gain sections 502 and 504 is not only more efficient, but also introduces less noise into the system that may arise from glitches or mismatches between different amplifiers. For example, each amplifier may have transient events that are avoided when they are in constant use, regardless of the range in which they are applied. Any peculiarities, ranging problems, or errors caused by amplifiers 512a and 512b will exist in all ranges in which they are applied. As will be discussed in more detail below, this can ensure consistency and smoothness of the overall trend and behavior of the measurement data, which is often a more important aspect than precisely measured amplitude in material measurements.

[0049] Similar to the case of chain 400, the combination 510 in chain 500 can be weighted by a coefficient α. The coefficient α can be dynamically selected to ensure a smooth transition over the ranging transition Δt (for example, using range mixing to avoid discontinuity D in Figure 3). The coefficient α can be set by the user, but is often set by a ranging algorithm (for example, algorithm 600 shown in Figure 6A). α can be set by gain, chain, or any method described herein relating to signal mixing.

[0050] In variations including chains 400 and 500, and others, seamless ranging may include automated ranging. Figure 6A provides an illustration of an automated ranging algorithm 600 that may be used in conjunction with seamless ranging in, for example, variations 400 and 500. Figure 6C shows the algorithm 600 in flowchart form.

[0051] Algorithm 600 changes the range as the measurement signal 650 shown in Figure 6B changes in increasing order from the ranges r1, r2, and r3. Signal 650 is measured at t=t TR(1-2) In this case, the range transitions from r1 to r2, and t TR(2-3) The transition occurs from range r2 to r3. Figure 6A shows the response of algorithm 600 in terms of applying dedicated gain chains for ranges r1, r2, and r3 over those transitions.

[0052] As shown in Figures 6A and 6C, algorithm 600 performs the transition from r1 to r2 (t TR(1-2) Prior to this, the gain configured for 100% r1 is provided during period 602 (for example, by drawing from the higher gain portion 404 in chain 400 in Figure 4, providing a higher gain to the lower of the two ranges). Figures 6A and 6C also show that algorithm 600 is configured when the measured signal transitions t TR(1-2)This indicates that when approaching r1, the gain profiles for r1 and r2 are mixed (e.g., drawn from the higher-gain portion 404 and the lower-gain portion 404). The r1 / r2 mixing period prior to this transition is labeled as 604. As discussed above, the mixing avoids data glitches and / or gaps during r1 / r2 range transitions. TR(1-2) After the r1 / r2 transition in , algorithm 600 applies the r2 gain without mixing (for example, drawing from the lower gain portion 402 in chain 400 in Figure 4). Figures 6A, 6B, and 6C show that the algorithm similarly applies by first mixing the gain profiles for r2 and r3 during period 608, and then providing only the r3 constituent gain during period 610. TR(2-3) This shows that r2 changes to r3.

[0053] Figure 6A also shows the region of hysteresis 612 during period 606 (r2 only). During hysteresis 612, there is no expected ranging (i.e., only one gain portion of the gain chain is active, which in this case is the gain chain with respect to r2). The gain applied during hysteresis may also be constant. This avoids alternating switching between ranges due to noise or signal fluctuations. Once the measured signal 650 moves closer to r3, the hysteresis period 612 ends. Period 614 represents the period expected by engaging the gain chain (not shown) with respect to r3 as the range change from r2 to r3 occurs. The gain chain corresponding to r3 is engaged during 614 for both calibration and to avoid transient events as discussed above. No hysteresis or expectation of the upper part of the range is shown with respect to the r1 / r2 transition, but it should be understood that they may be applicable to that transition as well.

[0054] Figure 6A shows the operation of algorithm 600 when the measured signal increases, but it should be understood that the algorithm applies similarly when the measured signal decreases (e.g., from a higher range r3 to a lower range r2, and then to the lowest range r1). This is shown via flowchart 620 in Figure 6D. In this case, algorithm 600 would predict the lower period of the range rather than the upper period of the range (e.g., t TR(3-2) In this case, the transition is downward from r3 to r2 (e.g., step 624 in chart 620).

[0055] Figures 6A, 6B, and 6C show algorithms 600 and 620, which handle range changes between three exemplary ranges r1, r2, and r3, but it should be understood that these can handle range changes between any number of ranges suitable for experimentation in the same manner. Other variations of algorithms 600 and 620 can include many other algorithms and / or range / parameter settings and any number of suitable range transitions.

[0056] Each of the mixers 410 and 510 in chains 400 and 500 can operate according to any preferred mixing algorithm to achieve the smoothing effect (302) shown in Figure 3. Mixers 401 and 501 may be digital. They may not require any independent calibration. In one modification, the mixed outputs of 410 and 510 may be controlled by an algorithm similar to the following. Output signal V (for mixer 402 or 502) = αE A +(1-α)E B (1) During the ceremony, E A This is the output of the first ADC (ADC A 408a or ADC A 508a), E B This is the output of the second ADC (ADC A 408b or ADC A 508b), α is, for example, a mixing parameter that can vary from 1 to 0.

[0057] It should be understood that Equation 1 is not the only mixing algorithm that can be applied by mixers 410 and 510. For example, the mixer may simply average the output of each path and reduce noise. Equation 1 is given by linear weighting (α) E A and E B This applies to the contribution. However, nonlinear weightings are also assumed and should be considered within the scope of this disclosure. In practice, the weightings may include any preferred mathematical form. Examples include, but are not limited to, quadratic polynomials, cubic polynomials, and any preferred polynomials. Exponential and logarithmic functions, and differential equations are all assumed within the scope of this disclosure.

[0058] The exact form of the weighted or mixed function should depend on factors such as the gains of the various amplifiers in the system (e.g., amplifiers in 402, 404, and 512 and amplifier 506), and other components such as ADCs (e.g., ADCs 408a, 408b, 508a, and 508b). This may also depend on the details of the mixers 401 and 510 used in the circuit. This may depend on the following exemplary characteristics of these components, e.g., frequency response, gain value, nonlinearity, and sensitivity to input variations. In addition, the parameter α does not need to vary from 1 to 0, as in the above embodiment. The parameter α and any other values ​​adopted by mixers 410 and 510 may depend on the details of the gain stages and gain 506 in chains 402, 404, and 512. This may include any suitable values ​​for balancing the gain and eliminating or reducing the discontinuity D (Figure 3).

[0059] Figure 7A shows another modification 700 that shares a gain stage while using multiple ADCs (i.e., ADC A 708a and ADC B 708b). Figure 7A shows the architecture of chain 700 itself. Figure 7B is a plot 750a comparing the response 750a of chain 700 with a conventional ranging system of the prior art, such as 120.

[0060] Chain 700 includes two signal paths 700a and 700b, each containing an ADC (ADC A 708a and ADC B 708b, respectively) and a multiplexer (mux 706a and 706b, respectively). Multiplexers 706a and 706b are selected from gain stages 704a-704c from gain chain 700c. Thus, signal paths 700a and 700b have independently configurable gains based on their selection.

[0061] Each independently configurable gain delivered to paths 700a and 700b can be any combination of the outputs of amplifiers 704a, 704b, and 704c, each having gains A1, A2, and A3, respectively. Gains A1, A2, and A3 may be 1, any preferred positive value greater than 1, and any preferred negative value with an absolute value greater than 1, respectively. The gains can be selected for any reason and on any basis, but they are typically selected by mux 706a and 706b based on the range of the input signal 702 to best adapt its signal. It should be understood that many different combinations are possible and within the scope of this disclosure.

[0062] For example, the input signal 702 may be within the range that is best amplified by the combined gain from gain stages 704a and 704b (i.e., a gain equal to the product of A1 and A2) and ADC A 708a. This range may correspond, for example, to the lower range r1 in Figure 6A that requires a relatively high gain. In this case, mux706a would select input 707a and send its gain to ADC A 708a. After processing in ADC A 708a, the signal is sent to mixer 710. In this case, mixer 710 would select only the ADC A 708a input (for example, by setting α in equation 1 to equal 1) because ADC A 708a is within the appropriate range and signal. At the same time, mux706b may be configured so that ADC 708b has a configured gain with respect to the upper range r2. This may be a lower gain with respect to the lower range r1 that corresponds to higher signal amplification. Simply as an embodiment, a lower gain than this may be A1. In this embodiment, ADC B 708b is not used to generate the output signal 712 as long as input 702 is within range r1. Typically, since they do not actively provide an output to mixer 710, paths 700b and their associated unused ranges would be considered cold. However, even while cold, paths 700b can still operate to avoid transient events that occur during turn-on or warm-up.

[0063] The input signal 702 increases, and therefore this is the transition t TR If there is a risk of saturating ADC A 708a by approaching the gain, ADC B 708b ("cold" range) may be engaged. The path associated with ADC B 708b can be set to a higher range (lower gain). For example, ADC B 708b is fed the output of gain stage A1 (704a), which would result in ADC B 708b being in a higher range (lower gain) than ADC A 708a in path 700a.

[0064] While the input signal 702 is at the desired level with respect to ADC A708a, the mixer 710 is configured so that only the output 712 receives the contribution of ADC A708a. This is the transition point t TR This corresponds to the lower range r1 in Figure 3, which is further away from the input signal 702, t TR As the transition t increases (towards the upper range r2 in which ADC B708b is configured), it becomes more advantageous for ADC B 708b to take over processing. TR Before that, ADC 708b “warms up” by beginning to measure the input signal 702. In this configuration, corresponding to step 614 in Figures 6A and 6C, mixer 710 is still configured to send only the signal from ADC A 708a to output 712. Once the transient event in ADC B 708b processing of the input signal 702 has disappeared, mixer 710 begins to provide output 712 with a signal that is a combination of the outputs from ADC A 708 and ADC B 708b. This mixed output may be, for example, given by equation 1. Mixer 710 progressively increases the contribution from ADC B 708b until the system is sufficient within the range r2. At that point, corresponding to step 606 in Figures 6A and 6C, mixer 710 may block or eliminate the contribution from ADC A 708a because ADC B 708b is configured for r2. In the exemplary case, mux706b is configured so that ADC B 708b receives a lower gain (A1 only, as opposed to the product of A1 and A2). This corresponds to input 707b. The generation of output 712 by mixing the signals from the two ADC paths 700a and 700b to smooth the transition across D (Figure 6A) is seamless ranging.

[0065] In this scenario, the singularities and / or errors associated with the gain stage 704a (gain of A1) are common between the measured signals 750a (Figure 7B) of both ranges r1 and r2 and their range paths 700a and 700b, respectively. Therefore, the transitions between ranges t TRThis exhibits gain commonality, which reduces discrepancies between ranges. The effect on the measured data is schematically shown in Figure 7B. Specifically, Figure 7B shows how the signal 750a measured by 700 is more similar in ranges r1 and r2 (parts A and B, respectively) than the same output measured by a prior art configuration (e.g., 100 shown in Figure 1). In other words, the measured signals 750a are more similar when they are measuring the same signal (seamless ranging) compared to completely different sets of gains within each range (prior art). In Figure 7B, both the prior art system and the seamless ranging system 750a have the same output with respect to part A (range r1).

[0066] Once the input signal 702b is passed to ADC B 708b, ADC A 708a is cold in this case. Even while cold, the gain of ADC A 708a remains configured to anticipate where the signal will proceed next. ADC A 708a may remain within the r2 configuration range, for example, to anticipate a return to that range. Alternatively, ADC A 708a may change its range by resetting mux 706b with respect to a different gain. ADC A 708a may do this by anticipating that the signal will continue to increase or decrease depending on the initial conditions of each signal path.

[0067] As discussed in the context of Figure 6D, the transition described above can be performed in reverse with respect to the decreasing input signal 702. In other words, if signal 702 is decreasing from range r2 to r1, the mixer would first be set to feed only the contribution from path 700b to output 712. This is because ADC B 708b is configured for range r2 by setting mux 708a to receive input 707b (lower gain A1). TRAs the signal decreases towards t, the ADC 708a is turned on to warm up and allow the transient to disappear. At this stage, the mixer 712 is still configured so that output 712 receives only the 708b contribution. Once input 702 is t TR When approaching, mixer 710 is configured to combine contributions 700a and 700b to produce a seamless transition. Input 702 is t TR When the gain decreases beyond r to r1, the mixer 710 is reset so that only the configured path with respect to r1 (i.e., 700a including ADC A 708a) contributes to the output 712. As discussed in the above embodiment, this gain may be the product of A1 and A2 set by mux706a.

[0068] In a system with multiple gain stages, such as the 700, the input signal 702 can be passed alternately between ADCs 708a and 708b as the input signal increases or decreases. Each time, the cold ADC will anticipate the range required for the changing signal, as described above. During this process, the gain can be changed for the cold ADC while the output is taken from the active ADC. This results in a constant output within the desired range, as shown in Figure 7B, and a reduced mismatch due to the gain variation within each range.

[0069] Figure 7B shows that the measurement signal 750a is t TR We show that the r1 / r2 transition in exhibits a discontinuity of magnitude 752. This is for illustrative purposes only and may not be present in all implementations. The discontinuity 752 is that the gains applied to paths 700a and 700b, which are configured for each range r1 / r2, are different from the transition t TRThis arises from a situation of slight mismatch. In many variations, it may be possible to adjust the gain for each path 700a and 700b to eliminate the discontinuity 752. However, it may be more important to configure the gain to best represent those individual ranges. In this case, the discontinuity 752 is a known artifact of the measuring electronic equipment and can be addressed in several ways (e.g., by curve fitting / smoothing) during post-processing of the measurement data 750a.

[0070] Figure 8 shows another modification 800, which includes a preamplifier 804a preceding the gain chain 700c and / or a preamplifier 804b in one of the two paths. Figure 8 shows the preamplifier 804b in path 700b associated with ADC B 708b. However, it should be understood that the preamplifier 804b can also be placed in a similar position in path 700a associated with ADC A 708a. Except for the addition of preamplifiers 804a and 804b, modification 800 is the same as modification 700 in Figure 7A.

[0071] Preamplifiers 804a and 804b can provide several benefits to Modification 800. For example, preamplifier 804a can buffer the input signal 702 from other components in Modification 800. This can be advantageous because directly connecting input 702 to multiple buffer or switching elements degrades performance. These elements often impart bias current and switching capacitance to input 702. Preamplifier 804b can typically be placed within a path (either 700a or 700b) associated with a range requiring extra gain. This could be, for example, the lowest range (e.g., range r1 in Figure 6A). "Wiring" the extra gain stage to one of the paths makes it simpler and easier to apply the appropriate gain to that path.

[0072] Figure 9 shows an interpolation algorithm 910 that is directed to eliminate or reduce discontinuities 752. Algorithm 910 may be implemented by mixer 710 (Figures 7 and 8) for both paths 700a and 700b.

[0073] In particular, in some applications in materials research, discontinuity 752 itself can be a greater problem than other sources of quantitative error. This is especially true when the overall characteristics of the measured signal 750a, rather than its precisely measured value, are most important for describing the material properties. In many cases, the measured values ​​may be assessed in relative or normalized terms to emphasize the behavior over precise amplitudes. In these cases, the mixer 710 can interpolate its two inputs from ADC 708a and 708b to maintain a smooth transition between ranges r1 and r2. Such interpolation can be performed via equation 1. This can also be performed using other suitable mathematical or signal processing means for interpolating the signals from ADC 708a and 708b. As shown in Figure 9, the interpolation 910 is typically performed over a transition time t TR The interpolation is performed only over a period 920 that is close to the specified time. Period 920 may correspond to Δt, for example, as shown in Figure 3. However, it should be understood that interpolation 910 does not need to be limited to any particular time period. Since the respective contributions of the signals from the two ADCs 708a and 708b are variable, interpolation 910 may be performed throughout the entire measurement.

[0074] Figure 10A shows Modification 1000, which includes an additional range of freedom with respect to gain, with selection for each path 1000a and 1000b associated with a plurality of amplifiers 1004a-1004n in a common gain chain 1000c. Gain stage selection can be performed by two sets of switch banks 1006a and 1006b in Modification 1000. Each bank includes a switch 1014a that can connect or disconnect a switch, e.g., a data converter (e.g., ADC) 1008a or 1008b, to each gain stage in chain 1000c. Each amplifier 1004a-1004n can be connected independently.

[0075] It should be understood that switch banks 1006a and 1006b can be implemented in several preferred ways. Solid-state switching may be used. Alternatively, mechanical relay switching may be used. Any other preferred switching or connection method may be used. Individual switches (e.g., 1014a) may exist and operate individually. Alternatively, they may operate as part of an integrated circuit or other integrated device. They may be triggered by any preferred means, including user input, any of the algorithms described herein (e.g., algorithms 600, 620, and 910, etc.). Switch banks 1006a and 1006b may also be operated dynamically so that the gains fed to the switching and data converters 1008a and 1008b can be changed dynamically (e.g., at any point in time within the ranges r1 and r2 in Figure 6A).

[0076] Figure 10A illustrates how a gain path can be constructed using a common gain chain to amplify an input signal. Points before and after each gain stage 1014a-1014n in the common gain chain 1000c can be selected from multiple ranges. In Figure 10A, switching means 1006a and 1006b and / or a controller can be used to select points on the common gain chain 1000c and pass the input signal to either the upper data converter 1008a or the bottom data converter 1008b.

[0077] As shown in Figure 10A, mixer 1010 selects or mixes the outputs from data converters 1008a and 1008b and feeds them to data output 1012. Mixer 1010 can operate in a manner similar to or identical to mixers 410, 510, and 710. For example, mixer 1010 may mix the outputs of 1008a and 1008b using equation 1. This may be done based on any information used by mixers 410, 510, and 710 (e.g., user input, algorithm 600, etc.).

[0078] Figure 10A shows only two converters, but it should be understood that Modification 1000 (and Modifications 500, 700, and 800) can be used with any suitable number of data converters. One exemplary configuration is to assign a data converter to each independent range. Therefore, if the measurement includes four ranges r1-r4, for example, four independent data converters may be used.

[0079] Figure 10A shows that Modification 1000 includes an arbitrary number (n) of gain stages 1004-1004n in the gain chain 1000c. Generally, the more gain stages included in 1000c, the greater the flexibility that allows data converters 1008a and 1008b to represent a particular range. In some modifications, such as Modification 1000, n is twice or more the number of data converters 1008m.

[0080] Figure 10A shows gain stages 1004a-1004n that appear to be of the same or similar type, but this is not necessarily the case. In modifications, it may be advantageous to use different types of gain stages with different gains. The advantage of having a common gain chain 1000c is that fewer parts of the system need to be calibrated. In conventional systems, two completely independent gain paths needed to be calibrated. In this disclosure, the gain stages can be calibrated independently of the range. This can reduce the time required to calibrate the entire system.

[0081] Typically, almost all or all gain stages in chain 1000c are active. In some cases, it may be useful to deactivate gain stages 1004a-1004n that are not in use (e.g., by making them active or generating expected ranges). For example, some types of gain stages 1004a-1004n may not adequately handle saturation without generating errors. In such cases, such gain stages would, advantageously, be deactivated once the risk of saturation is detected. Doing so may allow for faster transitions (i.e., by activating only the ranges where a certain range can adequately amplify the signal). Unused ranges 1004a-1004n may also be deactivated to reduce power draw-in, heat generation, etc.

[0082] Figure 10B shows an exemplary gain path (gain path A) that can be created using Modification 1000. Switch 1014c is engaged to create gain path A. This amplifies gain path A by gain stages 1004a and 1004b (without any other gain stages). The amplified signal is then sent to data converter 1008a. The path is then mixed with another path by mixer 1010 and sent to data output 1012. In a modification, mixer 1010 may send only the signal from gain path A to data output 1012. Otherwise, the paths may be mixed by any of the means or algorithms disclosed herein (e.g., equations, algorithm 600, etc.).

[0083] Figure 10C shows another gain path (gain path B), including two variations, namely high-range and low-range variations. Both the high and low variations use data converter 1008b instead of converter 1008a. Thus, gain path B can be engaged with gain path A separately and independently. Gain paths A and B can be mixed together by mixer 1010 to form data output 1012.

[0084] A higher-range path of gain path B may include less gain and be more appropriate for a higher range (e.g., r2 in Figure 6A). This is done by triggering switch 1014f, which causes the path to include gain from only one stage, i.e., 1004a. A lower-range path is obtained by triggering switch 1014h while switch 1014f is not triggered. The lower-range path includes two extra gain stages, i.e., 1004b and 1004c, along with gain stage 1004a. This gives it a much higher gain, which may be more appropriate for a lower range (e.g., r1 in Figure 6A).

[0085] Modification 1000 may switch between any of these gain paths as needed. This may be done, for example, according to any of algorithms 600, 620, and 910. For example, since gain path A has the lowest gain, modification 1000 may use gain path A first. This may simultaneously bring gain path B online, warm it up, and eliminate transients. In this scenario, gain path B will be in its lower range configuration, anticipating that it will be used first because the measured signal is increasing from a lower range (i.e., a lower range associated with gain path A). As the measured signal continues to increase, mixer 1010 may mix gain paths A and B, with gain path B in the lower range configuration. As the measured signal continues to increase, mixer 1010 may send only gain path B to data output 1012. As the signal continues to increase beyond this point, the higher range configuration of gain path B may be triggered by turning off 1014h and turning on 1014f. This will give the input signal 1002 the minimum amount of gain corresponding to being in the highest range (i.e., only the gain from the gain stage 1004a).

[0086] Figure 11 shows another modification 1100, which includes variable gain selection by another means, namely, gain stage selectors 1116a-1116n. Modification 1100 selects the gain from gains from two stages 1104a and 1104b. However, it should be understood that this is merely illustrative. Any preferred number n of gain stages 1104 may be included in 1100.

[0087] In modification 1000, each data converter 1108a-1108n is connected to its own gain stage selector 1116a-1116n. However, other configurations in which the data converters 1108 share the gain stage selector 1116 are also possible.

[0088] Modification 1100 includes a large number of data converters n. Generally, the number of converters n can be selected so that there is one converter per range. In other situations, it may be advantageous to include either more or fewer converters than the range. Multiple range / gain stages are also useful, for example, in pulse input signal measurement applications. If the input signal transitions across multiple ranges, it may be useful to measure its pulses across several ranges with different gains. It should be understood that any suitable number of gain stages, greater than or less than n, may be used.

[0089] It can be useful to have a range that is always measured at a certain point in a common gain chain, while other ranges alternately pass the signal between desired gains. One modification is to use a low-cost ADC, initialize the input signal with low gain, and use this information to quickly configure the gain in a high-quality ADC. This can be beneficial for inputs that vary between different sources. Input signals with large amplitude spikes can also cause problems for the measurement system. Therefore, by having multiple ADCs that measure simultaneously, accurate measurements can be achieved when the input is within its "normal" range, but it is still possible to measure signal spikes. In other modifications, the input can benefit from using different types of ADCs simultaneously to measure the signal. A high-speed ADC, along with a high-resolution ADC, will allow different types of signals to be measured and converted without sacrificing performance. All of these modifications can use predictive algorithms with other ADCs that measure the input signal for other purposes. Many communication signals exhibit this type of signal characteristic.

[0090] As shown in FIG. 11, the modification example 1100 includes a range mixer 1110. The range mixer 1110 mixes the outputs of the data converters 1108a-1108n and provides them to the data output 1112. The range mixer 1110 can mix the outputs according to any method disclosed herein in the context of other range mixers (e.g., in the context of the range mixer 1010). Many different types of mixing algorithms can also be designed to combine different ranges and more accurately measure varying input signals.

[0091] As shown in FIG. 11, each gain stage selector 1116a-1116n can provide any combination of the gain stages 1104a and 1104b to the data converters 1108a-1108n. The combination can be selected by any means of gain selection disclosed herein, including user input, any of the algorithms disclosed herein (e.g., 600, 620, and 910).

[0092] FIG. 12A is a schematic diagram of an exemplary mixing and auto-ranging algorithm 1200 that can be implemented by the range mixers 410, 510, 710, 1010, and 1110. The algorithm 1200 mixes three ranges A1, A2, and A3, as shown in FIG. 12A. For purely illustrative purposes, A1>A2>A3. It should be understood that higher gains are typically associated with lower ranges in the variable being measured, and vice versa. Thus, the exemplary gain configuration of A1>A2>A3 is most likely to correspond to the following measurement range configuration, i.e., r1<r2<r3. In this situation, the highest gain A1 would be applied to the lowest range in the measurement data r1, etc. FIG. 12A shows the gain increasing from A3 to A1 (from top to bottom) as the value of the measurement signal decreases. That is, it is for the case when the measurement signal decreases within the range from r3 to r1.

[0093] When the measured signal is within the highest range (e.g., range r3 in Figure 6A), algorithm 1200 applies the lowest gain A3. As the measured signal decreases and approaches the next lowest range, i.e., the range where the next higher gain A2 is desired, the mixers (e.g., 410, 510, 710, 1010, and 1110) become active. This occurs in stage 1204. In stage 1204, the mixer combines A3 and A2 to smooth the transition. In 1206, the transition between the A3 and A2 ranges is complete. The mixer applies only A2. In stage 1208, the measured data is definitely within the A2 range. Here, any switching or mixing by the mixer between any stage would be an error. Therefore, algorithm 1200 applies hysteresis to prevent changes in the expected range. This ensures that there are no erroneous switching of electronics based on noise or aberrations in the data. In step 1210, the measured data decreases further, approaching the lowest range in the measurement (e.g., r1 in Figure 6A) where the highest gain A1 is most appropriate. Therefore, algorithm 1200 "warms up" the A1 gain profile. The mixer does not actually engage the measured signal with the A1 gain at this point. Instead, it is switched on to eliminate any transient events that may occur. In step 1212, the mixer begins to actively mix the A2 and A1 ranges. This is because the measured signal is now close enough to the highest gain A1 / lowest measured range r1 to smooth the transition. Finally, in step 1214, the measured data is now definitely within the A1 range. The mixer provides only the A1 gain.

[0094] Figure 12A was explained in terms of the increase in gain from the lowest gain A3 to the highest gain A1 (the decrease in range from the highest measurement range r3 to the lowest measurement range r1), but it should be understood that Figure 12A is bidirectional. That is, algorithm 1200 can also proceed when the gain decreases from A1 to A3, corresponding to the increase in the range of measurement data from r1 to r3. In that case, algorithm 1200 would follow the steps in the reverse order, i.e., 1214-1202.

[0095] The automatic ranging algorithm can vary for any given application and does not need to be symmetric or linear, as shown in Figure 12A. An asymmetric variation 1250 is shown in Figure 12B. In Figure 12B, there are three ranges, namely 10, 1, and 0.1, defined by the digits of the measured data. Note that the digits 10, 1, and 0.1 refer to the digits of the range in the variable being measured (e.g., voltage). This differs from Figure 12A, where the ranges are referenced by their gains A1, A2, and A3. Since the gains are inversely proportional to the variable being measured, the lowest measurement range 0.1 corresponds to the highest gain (A 0.1 ) corresponds to the highest measurement range 10, which corresponds to the lowest gain (A 10 This corresponds to ). Since the change between the 10 and 0.1 ranges represents a two-order-of-magnitude change in the measured data, great care must be taken in range mixing. The measured signal is particularly small within the 0.1 range, and this can easily be overwhelmed by range mixing. Therefore, algorithm 1250 applies range mixing carefully.

[0096] When the measurement signal is within the highest measurement data range 10, the algorithm 1250 determines the lowest appropriate gain (A) for that range. 10 ) is applied. This is stage 1252 in Figure 12. As the measurement signal decreases and approaches 1, which is the next highest measurement data range, the mixer becomes active. This occurs in stage 1254. In stage 1254, the mixer applies 10(A) to smooth the transition. 10The gains for the ranges ) and 1(A1) are combined. At 1256, the transition between the 10 and 1 ranges is completed. The mixer applies only the gain for 1(A1). However, the difference in range between the 1 and 10 ranges is very large, so 10(A 10 The electronics for the measurement data range remain warmed up. No mixing is present, but the mixer is in a state where it can switch ranges as needed to prevent saturation. At stage 1258, the measurement data is definitely within range 1, so switching to range 10 is not possible. Any switching between stages or mixing by the mixer here would be an error. Therefore, algorithm 1250 applies hysteresis to prevent changes in the expected range. This ensures that there are no erroneous switching of electronics based on noise or aberrations in the data. At step 1260, the measurement data has decreased sufficiently to approach the lowest measurement data range of 0.1. At this step, the mixer anticipates a downward range change by engaging the electronics for the 0.1 range but keeping them offline (i.e., not mixing ranges). As the measurement data continues to decrease toward the 0.1 range, algorithm 1260 proceeds to step 1262. In this section, the mixer smooths the transition to the 0.1 range by using 0.1(A 0.1 The mixer actively combines the gains related to the range of ) and 1(A1). Finally, in step 1264, the measured data is here certainly within the range of 0.1. The mixer then uses the gain associated with the lowest 0.1 measured data range (A 0.1 ) only.

[0097] Figure 12B was illustrated in terms of the decrease in the measurement range (increase in gain) from the highest range of 10 to the lowest measurement data range of 0.1, but it should be understood that Figure 12B is bidirectional. That is, algorithm 1250 can also proceed if the measurement data is increasing from the range of 0.1 to 10 and the corresponding gain is decreasing. In that case, algorithm 1260 would follow the steps in the reverse order, i.e., 1264-1252.

[0098] Figures 13A and 13B show flowcharts representing range change prediction algorithms 1300 that may be implemented by a mixer when implementing the algorithms disclosed herein (e.g., 600, 620, 910, 1200, and 1250).

[0099] Algorithm 1300 is started by initializing the input signal. In step 1302, the input signal is measured. A first range A is activated for comparison with the input signal in step 1302. This comparison is performed in step 1304.

[0100] If range A is not desired, algorithm 1300 determines in step 1306 whether the range is too low or too high. If the range is too high, the range is reduced in step 1308a. If range A is too low with respect to the input signal to be measured, the gain with respect to range A is increased in step 1308b. Regardless of whether range A is increased or decreased, the next step 1310 waits for any transient effects caused by the gain change to dissipate. Following transient dissipation, algorithm 1300 performs step 1302 again, measuring the signal and comparing it to the modified gain with respect to range A.

[0101] If step 1304 determines that the gain associated with range A is desired with respect to the measured signal, algorithm 1300 proceeds to step 1312. In step 1312, the algorithm anticipates the transition from range A to the new range B, which "warms up" the electronics associated with the new range B. In step 1314, algorithm 1300 starts the input based on its assessment of the new range B and the measured input. In step 1316, algorithm 1300 measures the input in both ranges A and B. In step 1318, algorithm 1300 selects the best range of ranges A and B with respect to the measured input to be active (i.e., for use when measuring the input).

[0102] Algorithm 1300 then initiates the process of determining switching thresholds based on the measured inputs and current ranges A and B. In step 1320, algorithm 1300 determines whether the active range falls below the switching threshold of the lower range. If the active range falls below the threshold of the lower range, algorithm 1300 performs step 1322 to determine whether the cold or unused range of ranges A and B is within the lower range. If the cold range A or B is within the lower range, algorithm 1300 proceeds to step 1324 to begin mixing. If the cold range A is not within the lower range, algorithm 1300 sets the cold range to a lower range in step 1326, and then proceeds to step 1324 to begin mixing.

[0103] If algorithm 1300 determines in step 1320 that the active range does not fall below the lower switch threshold, it proceeds to step 1328. In step 1328, algorithm 1300 determines whether the active range exceeds the upper switch threshold. If so, algorithm 1300 proceeds to step 1330 to determine whether the cold or unused range of ranges A and B is the higher range. If the cold range A or B is in the higher range, algorithm 1300 proceeds to step 1324 to begin mixing. If the cold range A is not in the higher range, algorithm 1300 sets the cold range to the higher range in step 1332, and then proceeds to step 1324 to begin mixing.

[0104] If algorithm 1300 finds that the active range does not fall below the lower switch threshold (step 1320) and also does not exceed the upper switch threshold (step 1328), the algorithm proceeds to step 1334. In step 1334, algorithm 1300 applies hysteresis to prevent range changes. This is because the measured signal is not within the upper or lower thresholds of the range change. Therefore, any decision to change the range would be based on false noise or glitches in the data. Once hysteresis is applied, the algorithm proceeds to step 1324 and begins mixing.

[0105] In step 1324, algorithm 1300 initiates the step of starting the mixing. The first step is to verify that the cold range is stable. If the cold range is stable, the system is ready for mixing. Next, algorithm 1300 proceeds to step 1326 to determine whether the range should be mixed. If it is decided to mix, algorithm 1300 mixes the range in step 1328 and then provides the mixed signal as an output in step 1330. If the decision is not to mix, the algorithm sets the output to the active range in step 1332. If the cold range is not stable, algorithm 1300 proceeds from step 1324 to step 1332 and sets the output to the active range. After the output is set to the active range in 1332, the signal is then output in step 1330.

[0106] Ranging does not necessarily have to be performed exclusively by an algorithm. It can also be performed via hardware. Figure 14 shows the parameters input by one such exemplary hardware modification 1400. In 1400, there is a “primary” channel on which a named range can be measured and a “secondary” channel with less gain. In each ranging update, the percentage of full-scale indication on the primary channel can be used to determine the behavior as follows: [Table 1]

[0107] Figure 14 illustrates how the range mixing algorithm 1400 will behave with respect to different input levels. More specifically, Figure 14 illustrates how the algorithm 1400 will mix (i.e., "mix") different channel gains A and B based on the input (i.e., range, range enumeration, input voltage, preamplifier activation, stage B activation, stage C activation, channel A gain, and channel B gain). The input relates to two gain channels A and B and two sample stages B and C. The "range enumeration" is an integer representation of a particular range (i.e., the 10V range is "0", the 1V range is "1", the 100mV range is "2", etc.).

[0108] Figure 15 illustrates a measurement signal chain 1500 between an exemplary head unit 1550 and an exemplary measurement pod 1560, which may use variations 400, 500, 700, 800, 1000, 1100 and algorithms 600, 620, 910, 1200, 1250, 1300, and 1400. While Figure 15 illustrates certain aspects of seamless ranging in system 1500, it should be understood that system 1500 may be adapted to any variations disclosed herein.

[0109] As shown in Figure 15, the head 1550 includes a measurement channel 1502. In the exemplary case, there are two input measurement channels, one for range A and one for range B, each with its associated ADC. Note that in some modifications, each measurement unit 1560 will have an associated configuration 1500 that communicates with the head 1550. This means that a modification with three measurement pods 1560 may have six ADCs. It should be understood that any preferred number of measurement channels is possible, depending on the number of measurements and ranges involved, and this can substantially exceed two (e.g., three, four, or more). The measurement channel 1502 may be obtained from the measurement pod 1560 via several variable amplifiers 1520 and analog filters 1504, as shown in Figure 15. The gain on the amplifiers 1520 may be set as described in the context of gains 1520a-1520c in Figure 10-12. Channel 1502 may be combined with a range mixed signal 1508 (1506) and transmitted via lock-in for demodulation 1510. Demodulation may be indicated by a reference signal (e.g., reference (lock-in) and reference +90 degrees (lock-in) 1512) and undergo a digital filter 1514 for signal refinement.

[0110] The signal can be processed in any number of ways, including DC, AC, or lock-in processing. Range determination can be based on the peak value of the measured sample signal, regardless of the other processing performed for the measurement, because the peak value would cause amplifier overload. As shown in Figure 15, the range mixer 1508 may further provide outputs for range and setting 1516, which are ultimately fed back to the amplifier 1520 and analog filter 1504, specifically adjusting the gain and processing of the measured sample signal for ranges A and B, respectively. The range mixer 1508 may function as described above in the context of range mixers 410, 510, 710, 1010, and 1110. This process is referred to as continuous measurement ranging and / or range mixing. Its purpose is to ensure that there are no glitches or measurement discrepancies that would otherwise occur when the measurement pod 1560 has to change its acquisition parameters to adjust for changes in the range of the measured sample signal.

[0111] The measurement pod 1560 may further include digital (non-analog) circuitry capable of performing various functions, including analysis, data communication, command information, power regulation, timing, and communication with external devices. In a modified example, the measurement pod 1560 has the ability to deactivate this non-analog circuitry while performing a measurement or providing a source signal. Doing so reduces the amount of interference and noise in the signal or measurement. For the same reason, the digital signal in the measurement pod 1560 may be isolated from the source pod 1560 and the head 1550.

[0112] Other variations of system 1500 include any preferred number of heads 1550, source pods, and measurement pods 1560. For example, Figure 16 shows another exemplary variation 1600 in which the head unit 1550 may have six channels capable of supporting three measurement type pods 1560a and three source type pods 1560b. In this variation, the head 1550 is also shown connected to an optional computer 1602 and three exemplary sampled or test-operated devices (DUTs) 1570. Again, this configuration is merely illustrative. There is no requirement regarding an equal number of measurement pods 1950a and source pods 1950b. One source 1950a may, for example, provide excitation signals for all three DUTs 1570.

[0113] Various inventive aspects, concepts, and features of the present invention can be described and illustrated herein as being embodied in combination in exemplary embodiments, but these various aspects, concepts, and features can be used in many alternative embodiments, either individually or in various combinations and secondary combinations thereof. Unless expressly excluded herein, all such combinations and secondary combinations are intended to be within the scope of the present invention. Furthermore, various alternative embodiments relating to various aspects, concepts, and features of the present invention, such as alternative materials, structures, configurations, methods, circuits, devices and components, software, hardware, control logic, forms, fit, and functions, can be described herein, but such descriptions are not intended to be a complete or exhaustive list of available alternative embodiments, whether currently known or subsequently developed. Those skilled in the art can readily adopt one or more of the inventive aspects, concepts, or features in additional embodiments and uses within the scope of the present invention, even if such embodiments are not expressly disclosed herein.

[0114] In addition, some features, concepts, or aspects of the present invention may be described herein as preferred arrangements or methods, but such descriptions are not intended to imply that such features are required or necessary unless explicitly stated so. Furthermore, exemplary or representative values ​​and ranges may be included to aid in understanding this disclosure, but such values ​​and ranges are not intended to be constrained, and are intended to be critical values ​​or ranges only when explicitly stated so. Furthermore, exemplary or representative values ​​and ranges may be included to aid in understanding this disclosure, but such values ​​and ranges are not intended to be constrained, and are intended to be critical values ​​or ranges only when explicitly stated so. Parameters identified as “approximately” or “about” specified values ​​are intended to include both the specified value and values ​​within 10% of the specified value, unless otherwise explicitly stated. Furthermore, it should be understood that the drawings accompanying this application may, though not necessarily, be to scale and are therefore intended to teach various ratios and proportions evident in the drawings. Furthermore, various aspects, features, and concepts may be expressly identified herein as inventive or forming part of the present invention, but such identification is not intended to be exclusive. Rather, there may be inventive aspects, concepts, and features that are fully described herein without being expressly identified in that way or as part of a specific invention, and the present invention may instead be described in the appended claims. Descriptions of exemplary methods or processes are not limited to the inclusion of all steps as required in all cases, nor is the order in which the steps are presented construed as required or necessary unless expressly stated so.

Claims

[Claim 1] A measuring system, A gain chain configured to amplify an analog input signal, A range selector configured to select the gain between the analog input signal and a plurality of ADC outputs from a plurality of analog-to-digital converters (ADCs), wherein each ADC output has a path, and the gain of each output path is comprised of a plurality of gain stages in the gain chain. A mixer configured to combine the aforementioned multiple ADC outputs into a single mixed output, A measurement system equipped with the following features.

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