TWI642915B - Pyrometer system, fully-differential amplification circuit for amplifying an optical signal in a pyrometer, and method of operating a fully-differential dual amplification circuit - Google Patents

Abstract

This disclosure describes systems, methods and apparatus for improved high temperature measurement amplification. In particular, an amplification stage is disclosed which uses a dual differential transimpedance amplifier stage with a pair of parallel configuration transimpedance amplifiers that enables faster sampling and high signal-to-noise.

Description

Pyrometer system, fully differential amplifying circuit for amplifying an optical signal in a pyrometer, and method for operating a fully differential dual amplifying circuit

The disclosure is generally related to optical high temperature measurement. In particular, but not limiting, the present disclosure is directed to systems, methods and apparatus for improved amplifiers for optical high temperature metrology.

Claims based on the priority of Article 119 of the US Code 35

This patent application claims the use of a fully differential front end with the name "reverse bias and blind detection support" on December 23, 2014 to achieve high speed, low noise, low offset, high gain. The priority of the present application is hereby incorporated by reference.

In a manufacturing environment, measuring the temperature of an object without contact has proven to be a complex and arduous task. Objects in motion are often difficult to touch (eg, molten sapphire), and overheated objects can damage the temperature sensor. Objects of interest may also be easily damaged by contact, thus impeding the measurement of their temperature. A reliable means of measuring high temperatures It has evolved for centuries, from the original visual methods used by blacksmiths to forging steel to today's highly accurate means of industrial temperature measurement (eg, optical high temperature measurements).

The glow of hot objects is a well-known phenomenon. The hotter it is, the brighter it is. In fact, this phenomenon is one of the more important cornerstones of many modern technologies. Among these techniques is the temperature measurement of the radiation measurement, or the optical high temperature measurement.

The essence of the system is that an object or target of interest is viewed using some type of optics. The system is imaged on a type of electronic detector that has been accurately calibrated to produce a known relationship between input (light intensity) and output (temperature reading). This output is typically routed to a control system and used as a feedback to adjust the process on the fly.

Optical pyrometers typically use an amplifier to increase the voltage of a detected optical characteristic representative of the measured target. These amplifiers present a variety of challenges that have not been fully addressed for optical high temperature measurements. Accordingly, there is a need in the art for an improved amplification stage for an optical pyrometer.

A feature of the present invention is a high-speed, high-signal-to-noise, high-gain, and high-dynamic range fully differential amplifying circuit for amplifying an optical signal in a pyrometer, the fully differential amplifying circuit comprising: a system input (304) configured to be coupled to an anode of a primary photodetector (302); a second system input (306) configured to couple to the the main photodetector (302) is a cathode, wherein, when the first and second system input (304, 306) coupled to the main photodetector (302), the current i _p an optical system in the Passing between the second and first system inputs (306, 304); a transimpedance differential amplifier stage comprising: a primary bias circuit (308) configured to the primary photodetector ( 302) biasing between 0V and a reverse bias and having first and second outputs (328, 330); a first transimpedance amplifying circuit (312) having a first current input (316) And a first transimpedance voltage output (314), wherein: the first current input (316) is coupled to the first system input (304), a first The voltage input (318) is coupled to the first output (328) of the primary bias circuit (308), and a first voltage system and the light at the first voltage transimpedance output (314) The current i _{p is} proportional; and a second transimpedance amplifier circuit (320) having a second current input (324) and a second transimpedance voltage output (322), wherein: the second current input (324) Is coupled to the second system input (306), a second bias voltage input (326) is coupled to the second output (330) of the primary bias circuit (308), and a second voltage proportional to the system and the photocurrent _p i between the first and the second system input (306, 304) at the second voltage through a trans-impedance output (322); wherein the primary bias circuit ( 308) coupled to the first and second transimpedance amplifying circuits (312, 320) such that a 0V to a reverse bias exists across the primary photodetector (302); and a primary differential output The v ₁ system is configured for conversion to a temperature or reflection coefficient value in a processor.

Another feature of the present invention is a pyrometer system comprising: a primary photodetector (201); a dual differential amplifying circuit (202) comprising a pair of transimpedance amplifiers, the pair of transimpedance amplifiers coupled to the main photodetector (201), and having a photocurrent i proportional to the differential voltage of the two _p outputs (212, 214) generated by the main photodetector (201), but with different Gain; a first analog to digital converter (204) coupled to a first differential voltage output of the two differential voltage outputs (212) and configured to convert a first differential voltage output (212) Forming a corresponding digital value and having a first digital output (216) providing the corresponding digital value to a processor (210); a second analog to digital converter (206) coupled to the a second differential voltage output of the two differential voltage outputs (204) and configured to convert a second differential voltage output (214) to a corresponding digital value and having the corresponding digital value provided to the processor ( 210) a second digit output (218); and the processor (210) The system is coupled to the first and second digital outputs (216, 218) and has a selector (208) coupled to the first and second digital outputs (216, 218) And configured to select which of the first and second digit outputs (216, 218) will be processed by the processor, the processor (210) configured to convert the first and second digits A selected one of the outputs (216, 218) becomes a temperature or reflection coefficient value and has an output (220) that provides the temperature or reflection coefficient value.

Another feature of the present invention is a method of operating a fully differential amplification circuits double, the method comprising the Department of: receiving a photocurrent i _p, i _p of the photocurrent to a differential transimpedance differential amplifier stage via a main photodetector (350), comprising a first pair of transimpedance amplifying circuits (312, 320) arranged in parallel; via the differential transimpedance differential amplifier stage (350) to convert the photocurrent i _p into a differential output voltage v ₁ ; Providing the first differential output voltage v ₁ to a pair of differential voltage amplifier stages (430, 432) arranged in parallel, thereby converting the first differential output voltage v ₁ into a pair of second and third differential outputs having different gains Voltages v ₂ and v ₃ ; providing the second and third pairs of differential output voltages v ₂ and v ₃ to a processor via a pair of analog to digital converters (204, 206); selecting the second and third differentials Outputting one of voltages v ₂ and v ₃ for processing without a mechanical switch; converting one of the second and third differential output voltages v ₂ and v ₃ to a temperature or reflection Coefficient value.

102‧‧‧Photodetector

104‧‧‧Transimpedance amplifier

106‧‧‧Amplification level

107‧‧‧High gain output

108‧‧‧Selector

109‧‧‧Low gain output

110‧‧‧ analog to digital converter (ADC)

200‧‧‧ pyrometer system

201‧‧‧Main light detector

202‧‧‧ Fully Differential Amplifier Circuit (Double Differential Amplifier Circuit)

204‧‧‧First ADC

206‧‧‧Second ADC

208‧‧‧Selector

210‧‧‧ processor

212‧‧‧First differential voltage output

214‧‧‧Second differential voltage output

216‧‧‧first digital output

218‧‧‧second digital output

220‧‧‧ output

300‧‧‧ Fully Differential Amplifier Circuit

302‧‧‧Main light detector

304‧‧‧First system input

306‧‧‧Second system input

308‧‧‧main bias circuit

312‧‧‧First transimpedance amplifier circuit

314‧‧‧First transimpedance voltage output

316‧‧‧First current input

318‧‧‧First bias voltage input

320‧‧‧Second transimpedance amplifier circuit

322‧‧‧Second transimpedance voltage output

324‧‧‧second current input

326‧‧‧Second bias voltage input

328‧‧‧ first output

330‧‧‧second output (second switch)

350‧‧‧Differential transimpedance amplification stage (blind level)

360‧‧‧Electrical circuit

430, 432‧‧‧Differential voltage amplifier stage

434, 436‧‧‧Amplification

438, 440‧‧‧Amplification

502‧‧‧Blind light detector

512‧‧‧ third transimpedance amplifier circuit

518‧‧‧Voltage input

520‧‧‧fourth transimpedance amplifier circuit

526‧‧‧Voltage input

554, 556‧‧‧ comparator

1100‧‧‧ computer system

1101‧‧‧ Processor

1102‧‧‧Cache memory unit

1103‧‧‧ memory

1104‧‧‧RAM

1105‧‧‧ROM

1106‧‧‧Basic Input/Output System (BIOS)

1107‧‧‧Storage Control Unit

1108‧‧‧ Storage

1109‧‧‧Operating system

1110‧‧‧Execution file

1111‧‧‧Information

1112‧‧‧API application

1120‧‧‧Network interface

1121‧‧‧ Drawing Control

1122‧‧‧Video interface

1123‧‧‧Input interface

1124‧‧‧Output interface

1125‧‧‧Storage device interface

1126‧‧‧Storage media interface

1130‧‧‧Network (network section)

1132‧‧‧ display

1133‧‧‧ Input device

1134‧‧‧ Output device

1135‧‧‧Storage device

1136‧‧‧Storage media

1140‧‧ ‧ busbar

i _d ‧‧‧dark offset current

i _p ‧‧‧Photocurrent

R _f ‧‧‧Responsive resistance

v ₁ ‧‧‧Differential voltage (main differential output)

v ₂ , v ₃ ‧‧ ‧Differential voltage output

v ₄ ‧‧ ‧blind differential output

v ₅ ‧‧‧Differential output

v _t ‧‧‧Differential voltage

The various objects and advantages of the present invention, as well as the more complete understanding of the invention. It's easier to understand.

1 is a conventional pyrometer system having a photodetector and a transimpedance amplifier having a feedback resistor _Rf , wherein the gain is proportional to the feedback resistor _Rf ; An embodiment of a pyrometer system; FIG. 3 depicts an embodiment of a fully differential amplifier circuit for amplifying an optical signal in a pyrometer; FIG. 4 is a diagram depicting a fully differential amplifier circuit having an additional gain stage. In one embodiment, the additional gain stage provides a second gain level for the differential output of the differential transimpedance amplification stage discussed in FIG. 3; FIG. 5 is another embodiment depicting a fully differential amplification circuit; FIG. Yet another embodiment of a fully differential amplifying circuit; FIG. 7 is a detailed view depicting a fully differential amplifying circuit; FIG. 8 is a detailed view depicting a fully differential amplifying circuit, but with a reverse switching state; FIG. In still another embodiment of the differential front end, the differential front end provides two differential voltage signals to a pair of analog to digital converters; FIG. 10 depicts an embodiment of a pyrometer system; and FIG. 11 shows an apparatus Example schematic representation of an embodiment.

The disclosure is generally related to optical high temperature measurement. In particular, but not limiting, the disclosure is directed to systems, methods, and methods for improved amplifiers for optical high temperature measurements device.

The word "example" is used herein to mean "as an example, instance, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

The term "differential amplifying circuit" is used herein to mean an amplifier having two driven inputs.

The term "amplification stage" is used herein to refer to a circuit or system having one or more inputs and one or more outputs proportional to (but amplified) the one or more inputs. An amplifier stage can include one or more amplifiers, such as operational amplifiers, BJTs, MOSFETs, and others.

The term "biasing circuit" is used herein to refer to a circuit that is configured to apply a bias voltage to a larger portion of a larger circuit or system.

The term "differential voltage amplifier stage" is used herein to refer to a circuit having two driven voltage inputs and a differential voltage output.

The terms "differential input" and "differential output" are used herein to indicate an input or output having two pins and a voltage between the two pins.

The terms "blind photodetector", "blind photocurrent", "blind bias", and "blind" are all referred to as an amplifier circuit for consideration or subtraction from the measurement of a primary photodetector. A characteristic of leakage current.

The term "coupled to" may refer to a direct connection between components, such as via an uninterrupted wire or lead, or a connection between components, such as via another component or circuit. For example, two capacitors can pass through a diode or inductor To couple with each other.

Conventional optical pyrometers suffer from low signal-to-noise ratios, errors caused by leakage currents in photodetectors, and are not capable of handling a wide range of radiation amplitudes found in high temperature measurements. For example, because the photocurrent may be as low as 10 ^-13 amps, significant amplification is required. In the current single-stage amplifiers used for high temperature measurements, the gain required to detect such small signals requires a very large feedback resistor _Rf (see a conventional single stage amplification system of Figure 1). 1 is a conventional pyrometer system having a photodetector 102 and a transimpedance amplifier 104 having a feedback resistor _Rf , wherein the gain is proportional to the feedback resistor _Rf . It can be seen that in situations where a large gain is required, such as in the case of high temperature measurements, _Rf must typically be very large in order to be able to see such small signals. However, a large R _f also corresponds to high noise. Thus, the use of a single stage transimpedance amplifier, such as 104, is inherently limited by high noise or insufficient gain.

The output of the transimpedance amplifier 104 is transmitted in two directions: (1) to another amplification stage 106; or (2) to a mechanical selector 108 without additional gain. It is also noted that the gain is proportional to the magnitude of the feedback resistor _Rf , which then causes large noise in the amplified signal.

After painstaking attempts to various modifications, such as the conventional magnification scheme depicted in FIG. 1, the present invention recognizes that these problems may be a single-stage non-differential amplifier (eg, 104) used in the art tradition. inherent. Although the designer of the pyrometer always uses a single-stage non-differential amplifier, the inventor of the present invention wondered whether a completely different amplification structure could overcome the single-stage non-differential amplification that the inventors believe to be in the pyrometer. Limiter.

Differential amplifiers have not previously been used in pyrometers because differential amplifiers are commonly used in situations where the measurement range is quite narrow (i.e., a small dynamic range measurement is required). In high temperature measurements, the photocurrent may vary between ^10-13 amps to 10 ^-6 amps (seven orders of magnitude), and thus differential amplifiers are not considered suitable for this type of detection. In addition, the differential amplification device introduces increased components and increased cost and complexity for the amplification system.

Despite these shortcomings, the inventors of the present invention still model a differential amplifier circuit for measuring photocurrent in a pyrometer and unexpectedly see promising results (i.e., compared to decades). The one achieved in the single-stage non-differential amplification stage is lower noise, a wider dynamic range, and a faster sampling rate).

The inventor of the present invention also recognizes that the detector current can be increased by adding a reverse bias to the photodetector (hence, it requires less amplification and therefore less noise). . The disadvantage of such an adjustment is that the photodetector will see an increase in leakage current as a function of increased reverse bias. Leakage currents are temperature dependent, and therefore, software-based calibration alone is a factor that makes it difficult to precipitate leakage currents at the high temperatures at which the pyrometers operate (since they are often stuck to or in the vicinity of the thermal processing chamber). To account for leakage current, a "blind" bias is applied to a "blind" photodetector that is isolated from as much optical and IR radiation as possible. In this manner, the current from the blind photodetector is expected to represent only the leakage current, and if the bias applied to the blind photodetector is the bias applied to the primary photodetector If the voltage is the same, the current from the blind photodetector should be an estimate of the value of the leakage current in the primary photodetector. The measurement from the biased blind light detector can be subtracted from the measurement of the primary photodetector to account for or remove the effect of the leakage current on the measured temperature. The blind bias is applied to and applied to the primary light The detector is biased the same size to bias the blind detector, but the blind detector is isolated from almost all sources so that its output is almost entirely due to the generation of the blind detector. Caused by the reverse biased leakage current. In this manner, the output of the blind photodetector represents the portion of the signal from the primary photodetector due to leakage current from the primary photodetector. By subtracting the output of the blind photodetector from the output of the primary detector, leakage current can be cancelled from the measurement regardless of the bias voltage and temperature of the amplification system.

Another problem with conventional high temperature measurement amplification schemes can also be seen in Figure 1, where a second gain stage 106 is used to handle a wide swing in signal strength in the case where different selectable gains are desired. It can be implemented such that the outputs of the high gain 107 and the low gain 109 are present. A selector 108, typically a mechanical switch, selects which of the outputs 107, 109 is passed to an analog to digital converter 110 (ADC). During a processing pass, the temperature of the measured target may change drastically such that the selector 108 must switch between the high gain output 107 and the low gain output 109, and thus this may be in the data Create a seam in the middle.

To address this seam in the data, the inventors have implemented a pair of ADCs 204, 206 (see Figure 2), each of which receives a differential output from a fully differential amplifier circuit 202, and each ADC is provided A digital output 216, 218 to a selector 208 of a processor 210. Unlike the conventional method in which only one amplified signal would reach the processor, the inventor's solution is to enable both digital output 216, 218 to reach the processor, thus enabling selection between gain stages. It is executed in software and can be executed at any point in time. In this manner, the seam does not occur when the selector 208 switches between the outputs 216, 218.

A more detailed description of the systems, methods and apparatus depicted in Figures 2-9 will now be discussed.

FIG. 2 is a diagram of a pyrometer system 200. The system 200 can include a primary photodetector 201 that may or may not be biased, and if biased, may be biased between 0V and a reverse bias, where There is no limit to the magnitude of the reverse bias. The system 200 can also include a dual differential amplification circuit 202 that can include a pair of transimpedance amplifiers, such as transimpedance operational amplifiers. The pair of transimpedance amplifiers can be configured to be coupled to the primary photodetector 201 such that the transimpedance amplifier converts a photocurrent i _p through the primary photodetector 201 into a plurality of transimpedances The voltage at an output of each of the amplifiers. Since the transimpedance amplifiers are arranged in parallel, the output can be a differential voltage that provides less noise than a single-stage non-differential amplifier with equivalent gain (or according to the same noise level). A larger gain, or a better signal-to-noise ratio). The double differential amplifier circuit 202 may have two outputs 212, 214 is proportional to the differential voltage current i _p of the light by the photodetector 201 is mainly generated. However, the two differential voltage outputs 212, 214 can have different gains.

Each of the two differential voltage outputs 212, 214 can be coupled to a different analog to digital converter (ADC), such as the first ADC 204 and the second ADC 206. The first ADC 204 can be configured to convert the first differential voltage output 212 to a corresponding digital value. The first ADC 204 can also have a first digital output 216 that provides the corresponding digital value to the processor 210.

The second ADC 206 can be configured to convert the second differential voltage output 214 to a corresponding digital value. The second ADC 206 can also have a second digital output 218, The corresponding digit value is provided to the processor 210.

The processor 210 can be coupled to the first and second digital outputs 216, 218. The processor 210 can have a selector 208 (eg, a switch) coupled to the first and second digital outputs 216, 218. The selector 208 can be configured to select which of the first and second digit outputs 216, 218 to be processed by the processor 210. Moreover, the processor 210 can be configured to convert one of the first and second digit outputs 216, 218 to a temperature or reflection coefficient value and can have an output that provides the temperature or reflection coefficient value. 220. Typically, the reflection coefficient value is used to calibrate the temperature measurement by indicating a reflectance of the surface of a target. This calibration can then be used to improve the accuracy of the temperature measurement. Therefore, measurements for both temperature and reflection coefficient can be accomplished by the system 200.

The dual differential amplifier circuit 202 can include a primary bias circuit configured to cause a bias on the primary photodetector 201. This bias range can range from 0V to a reverse bias, and the amplitude of the reverse bias is not limited. A larger reverse bias reduces the capacitance across the primary photodetector 201 and enables a higher sampling rate. However, the lower capacitance also represents a large leakage current, so it is necessary to process and precipitate an increased leakage current factor at an increased speed. Such currents are particularly troublesome in this application because they increase with temperature, and the temperature of the system 200 is typically between 35 °C and 45 °C (which is significantly higher than the environment).

3 is an illustration of an embodiment of a fully differential amplification circuit 300 for amplifying an optical signal in a pyrometer. This circuit 300 can be high speed, high gain, and has a high dynamic range, i.e., a combination of attributes that have proven to be impossible in conventional high temperature metrology amplification schemes. The system 300 achieves this via some of the structural features described below. One of the systems 300 can include a first system input 304 and a second system input 306 that are configured to be coupled to an anode and a cathode of a primary photodetector 302, respectively. In other words, the amplifying circuit 300 may be integrated with the detecting hardware during manufacture and sale, or may not be integrated. For example, an LED driver, an LED, an optical fiber coupled to the processing chamber, and a detector can be sold as a package that is separate from the amplifying circuit 300. When the first and second system inputs 304, 306 coupled to the primary photodetector 302, an optical system through an input current i _p 306, 304 between the first and second systems. In other words, as seen in FIG. 3, the polarity of the current i _p optical system and the photodetector 302 opposite to the flow.

The circuit 300 can also include a differential transimpedance amplification stage 350. The first amplification stage 350 has an input configured to receive the photocurrent i _p and convert the photo current i _p into a differential under a certain transimpedance gain (also involving a gain from a current to voltage transition) Voltage v _t . Assuming that the two amplifier stages produce the same noise level, the use of a differential transimpedance amplifier stage 350 allows for at least a 2 x gain factor compared to a single amplifier circuit. For example, the transimpedance amplifier circuit on a single line 10 ^-10 Amp converting a photocurrent i _p 1V be a case where the output of the differential system is provided that illustrates the generation 314 of a first transimpedance amplifying circuit 312 outputs + 1V And at the output 322 of the second transimpedance amplifying circuit 320 produces an output of -1V. Therefore, the differential voltage v ₁ is 2V, or twice the gain that a single amplifier can achieve. However, the noise penalty for this increased gain is not better than the noise difference seen in a single amplifier. Thus, the differential transimpedance amplification stage 350 produces a higher signal to noise ratio than the high temperature measurement amplification stage of the prior art.

The differential transimpedance amplifier stage 350 can include a primary bias circuit 308 that is configured to bias the primary photodetector 302 via the first and second transimpedance amplifying circuits 312, 320. The primary bias circuit 308 is not required and, in some embodiments, can be connected to Replaced by grounding. In the case where a bias voltage is applied, it may range from 0V to some reverse bias. A polarity of the primary bias circuit 308 is shown such that a reverse bias exists across the primary photodetector 302. The primary bias circuit 308 can have a first and second output 328, 330.

The differential transimpedance amplifier stage 350 can also include a first transimpedance amplifier circuit 312 having a first current input 316 and a first transimpedance voltage output 314. Details of an embodiment of the transimpedance amplifying circuits 312, 320 can be seen in Figures 7 and 8. The first current input 316 can receive the photocurrent i _p , and the first transimpedance amplifying circuit 312 can convert the current into a first output voltage that is seen at the first transimpedance voltage output 314 .

The first current input 316 can be coupled to the first system input 304 and the first bias voltage input 318 can be coupled to the first output 328 of the primary bias circuit 308 . In other words, the first transimpedance amplifying circuit 312 can have two inputs - one for the current from the primary photodetector 302 and one for a first output equal to the primary bias circuit 308 A bias voltage reference voltage at 328.

A first output voltage can be seen at the first transimpedance voltage output 314, and the first output voltage can be proportional to the photocurrent _ip .

The differential transimpedance amplifier stage 350 can also include a second transimpedance amplifier circuit 320 having a second current input 324 and a second transimpedance voltage output 322. The second current input 324 can receive the photocurrent i _p , and the second transimpedance amplifying circuit 320 can convert the current into a second output voltage seen at the second transimpedance voltage output 322 .

The second current input 324 can be coupled to the second system input 306 , and the second bias voltage input 326 can be coupled to the second output 330 of the primary bias circuit 308 . In other words The second transimpedance amplifying circuit 320 can have two inputs - one for the current from the second transimpedance amplifying circuit 320 to the main photodetector 302, and one for one equal to A reference voltage of a bias voltage at the second output 330 of the primary bias circuit 308.

A second output voltage can be found in the second trans-impedance voltage output 322, and this second output voltage may be proportional to the photocurrent i _p, but having a second and the first output 314 of the voltage across the impedance An opposite polarity of the output voltage. Thus, a differential voltage v ₁ has a magnitude that is twice the first or second output voltage and therefore has a greater gain than would be provided by any of the transimpedance amplification circuits alone.

Referring to Figure 4, Figure 4 is another embodiment depicting a fully differential amplifier circuit. The difference between FIG. 4 and FIG. 3 is that FIG. 4 includes additional gain stages (ie, first differential voltage amplifier stage 430 and second differential voltage amplifier stage 432). The gain stages provide two gain levels for the differential output of the differential transimpedance amplification stage discussed in FIG. 3 to produce a second differential voltage output v ₂ and a third differential voltage output v ₃ , where the second differential voltage output v ₂ and the third differential voltage output v ₃ correspond to the first differential voltage output 212 and the second differential voltage output 214 of FIG.

Referring to Figure 5, Figure 5 is another embodiment depicting a fully differential amplifier circuit. The difference between FIG. 5 and FIG. 4 is that the first differential voltage amplifier stage 430 can be comprised of an amplification stage 434 and an amplification stage 436, and the second differential voltage amplifier stage 432 can be comprised of an amplification stage 438 and an amplification stage 440.

Referring to Figure 6, Figure 6 depicts yet another embodiment of a fully differential amplifier circuit. FIG. 6 differs from FIG. 4 in that the fully differential amplifying circuit can additionally include a blind stage 552, a comparator 554, and a comparator 556. The blind stage 552 can include a blind light detector and a blind bias circuit. The blind light detector is isolated from most of the photon radiation seen by the primary light detector, but is identical in structure to the primary light detector to represent one of the primary light detectors 302 Leakage current. The blind biasing circuit is coupled to a third transimpedance amplifier circuit 512 and a voltage input 518, 526 of a fourth transimpedance amplifier circuit 520, and is configured to utilize and span the primary photodetector 302. The bias voltage is equal to the magnitude of the bias to bias the blind photodetector 502. The blind stage 552 can output a blind differential output v ₄ .

Each of comparator 554 and comparator 556 has a pair of inputs coupled to the primary differential voltage output v ₁ and the blind differential voltage output v ₄ , the comparators 554, 556 having a polarity such that the pair is compared A differential output v ₅ of the 554, 556 is equal to a difference between the primary differential output v ₁ and the blind differential output v ₄ .

Referring to FIGS. 7-8, FIGS. 7-8 are detailed views depicting a fully differential amplifying circuit of FIG. 6, wherein the first differential voltage amplifier stage 430 and the second differential voltage amplifier stage 432 of FIG. 6 have been respectively modified. The first differential voltage amplifier stage 430 and the second differential voltage amplifier stage 432 of 5 are represented. All of the first transimpedance amplifier circuit 312, the second transimpedance amplifier circuit 320, the third transimpedance amplifier circuit 512, and the fourth transimpedance amplifier circuit 520 use the transimpedance amplifier of FIG. 1 with a feedback resistor such as R _f . 104 to indicate.

The value of the feedback resistor in all transimpedance amplifier circuits can be any suitable value, and the values of the feedback resistors can be the same or different from each other. For example, this is possible: R ₁ = R ₂ = R _f , R ₁ = R ₂ ≠ R _f , R ₁ ≠ R ₂ ≠ R _f ... and so on. Moreover, a single resistance symbol in all transimpedance amplifier circuits does not mean that only one resistor is used in the transimpedance amplifier circuit. Those of ordinary skill in the art will appreciate that a single resistance symbol in all transimpedance amplifier circuits is only one equivalent resistance symbol, and that it may include multiple resistors connected in series and/or in parallel.

It should be noted that the fully differential amplifier circuit may additionally include a first switch 328 and a conductive loop 360 between the first and second system inputs 304, 306. The first switch 328 selectively couples the first system input 304 to the first current input 316 of the first transimpedance amplifying circuit 312. The electrically conductive loop 360 includes a second switch 330 that selectively shorts the first and second system inputs 304, 306. The first switch and the second open relationship are alternately switched such that the primary photodetector 302 is selectively switched out of the fully differential amplifying circuit.

Referring to Figure 8, Figure 8 is a detailed view depicting a fully differential amplifier circuit. The difference between FIG. 8 and FIG. 7 is that the switching state of the fully differential amplifying circuit of FIG. 8 is reversed.

In an embodiment, the primary biasing circuit 308 can include two voltage sources, each configured to apply an opposite bias to one side of the primary photodetector 302. One such embodiment can be seen in Figure 9, with particular reference to the anode bias and cathode bias.

Referring to Figure 10, Figure 10 depicts an embodiment of a pyrometer system. It should be noted that two pyrometer systems can be integrated to sense the temperature of different channels.

In addition to the specific physical devices described herein, the systems and methods described herein can be implemented in a computer system. 11 is a diagrammatic representation of an embodiment of a computer system 1100 that can be executed within the computer system 1100 for enabling a device to perform or perform the features and/or methods of the present disclosure. One or more. The components in FIG. 11 are merely examples and do not limit any hardware, software, firmware, embedded logic components, or one or more of such components of a particular embodiment that implements the disclosure. Combination use or The scope of function. Some or all of the illustrated components may be part of the computer system 1100. For example, the computer system 1100 can be a general purpose computer (eg, a laptop) or an embedded logic device (eg, an FPGA), to name but two non-limiting examples.

The computer system 1100 includes at least one processor 1101, such as a central processing unit (CPU) or an FPGA, to name two non-limiting examples. The computer system 1100 can also include a memory 1103 and a storage 1108 that communicate with each other via a bus 1140 and communicate with other components. The bus 1140 can also have a display 1132, one or more input devices 1133 (which can include, for example, a small keyboard, a keyboard, a mouse, a stylus, etc.), one or more output devices 1134, One or more storage devices 1135, and various non-transitory physical computer readable storage media 1136 are coupled to each other and to one or more of the processor 1101, memory 1103, and storage 1108. All of these components can be interfaced to the busbar 1140 either directly or via one or more interfaces or adapters. For example, the computer readable storage medium 1136 of the various non-transitory entities can interface with the busbar 1140 via the storage media interface 1126. Computer system 1100 can have any suitable physical form including, but not limited to, one or more integrated circuits (ICs), printed circuit boards (PCBs), mobile handheld devices (eg, mobile phones or PDAs), laptops, or Notebook, decentralized computer system, grid computing, or server.

The processor 1101 (or central processing unit (CPU)) optionally includes a cache memory unit 1102 for temporary local storage of instructions, data, or computer addresses. The processor 1101 is configured to facilitate execution of computer readable instructions stored on a computer readable storage medium of at least one non-transitory entity. Computer system 1100 can provide due to this processing The processor 1101 performs computer readable reading of one or more non-transitory entities such as the memory 1103, the storage 1108, the storage device 1135, and/or the storage medium 1136 (eg, read only memory (ROM)) The function of the software embodied in the storage medium. The computer readable storage medium of the non-transitory entity can store software that implements a particular embodiment, such as the methods disclosed herein, and the processor 1101 can execute the software. The memory 1103 can be from a computer readable storage medium (eg, mass storage devices 1135, 1136) of one or more other non-transitory entities, or from a suitable interface such as the network interface 1120. Or multiple other sources to read the software. The software may cause processor 1101 to perform one or more methods described herein or depicted, or one or more steps of one or more methods. Performing such a method or step can include defining a data structure stored in memory 1103 and modifying the data structure as directed by the software. In some embodiments, an FPGA may store instructions for performing the functions as described in the disclosure herein. In other embodiments, the tough system includes instructions for performing the functions as described in the disclosure herein.

The memory 1103 can include various components (eg, a non-transitory physical computer readable storage medium) including, but not limited to, a random access memory component (eg, RAM 1104) (eg, a static RAM "SRAM", a dynamic RAM "DRAM", etc.), a read-only component (eg, ROM 1105), and any combination thereof. ROM 1105 can function to communicate data and instructions unidirectionally to processor 1101, and RAM 1104 can function to communicate data and instructions to processor 1101 in both directions. ROM 1105 and RAM 1104 can comprise any suitable non-transitory physical computer readable storage medium as described below. In some examples, ROM 1105 and RAM 1104 are computer readable storage media containing entities for performing non-transitory methods of the methods disclosed herein. In an example, a basic input/output system 1106 (BIOS) can be stored In the memory 1103, it includes a basic routine that facilitates, for example, transferring information between components within the computer system 1100 during startup.

The fixed storage 1108 is bidirectionally coupled to the processor 1101, which is optionally permeable to the storage control unit 1107. The fixed storage 1108 provides additional data storage capacity and may also include any suitable non-transitory physical computer readable media as described herein. The storage 1108 can be used to store the operating system 1109, EXEC 1110 (executive file), data 1111, API application 1112 (application), and the like. Typically (although not always), the storage 1108 is a primary storage medium (e.g., a hard disk) that is slower than the primary storage (e.g., memory 1103). The storage 1108 can also include a compact disc drive, a solid state memory device (e.g., a flash-based system), or a combination of any of the above. In the appropriate case, the information in the storage 1108 can be incorporated as a virtual memory in the memory 1103.

In one example, storage device 1135 can be removably interfaced with computer system 1100 via a storage device interface 1125 (eg, via an external port connector (not shown)). In particular, the storage device 1135 and an associated machine readable medium can provide non-volatile and/or volatile information for machine readable instructions, data structures, program modules, and/or other materials for the computer system 1100. Sexual storage. In one example, the software may reside entirely or partially within one of the machine readable media on storage device 1135. In another example, the software may reside entirely or partially within the processor 1101.

The busbar 1140 is connected to a wide variety of subsystems. Here, reference to a bus bar may encompass one or more digital signal lines that function as a common function where appropriate. The bus bar 1140 can be any one of several types of bus bar structures, including but not limited to a memory bus, a memory controller, a peripheral bus, a local bus, and Any combination of these utilizes any of a variety of bus bar architectures. As an example and not by way of limitation, such an architecture includes an industry standard architecture (ISA) bus, a enhanced ISA (EISA) bus, a micro channel architecture (MCA) bus, and a video electronic standards association local. Busbar (VLB), a peripheral component interconnect (PCI) bus, a PCI-Express (PCI-X) bus, an accelerated graphics (AGP) bus, a hyper-transport (HTX) bus, and a serial A technology connection (SATA) bus, and any combination thereof.

Computer system 1100 can also include an input device 1133. In one example, a user of computer system 1100 can enter commands and/or other information into computer system 1100 via input device 1133. An example of an input device 1133 includes, but is not limited to, an alphanumeric input device (eg, a keyboard), a pointing device (eg, a mouse or trackpad), a trackpad, a joystick, a game A handle, an audio input device (eg, a microphone, a voice response system, etc.), an optical scanner, a video or still image capture device (eg, a camera), and any combination thereof. The input device 1133 can be interfaced to the bus bar 1140 via any of the various input interfaces 1123 (eg, the input interface 1123), including but not limited to tandem, parallel, gaming, USB, FIREWIRE, THUNDERBOLT, Or any combination of the above.

In a particular embodiment, when computer system 1100 is connected to network 1130, computer system 1100 can communicate with, for example, mobile devices and other devices of the enterprise system that are connected to network 1130. Communication to and from the computer system 1100 can be transmitted through the network interface 1120. For example, the network interface 1120 can receive incoming communications (eg, requests or responses from other devices) in the form of one or more packets (eg, Internet Protocol (IP) packets) from the network 1130, and the computer The system 1100 can store the incoming communication in the memory 1103 for use. For processing. Computer system 1100 can similarly store outgoing communications (eg, requests or responses to other devices) in the form of one or more packets in memory 1103 and from network interface 1120 to network 1130. The processor 1101 can access the communication packets stored in the memory 1103 for processing.

Examples of the network interface 1120 include, but are not limited to, a network interface card, a data machine, and any combination thereof. An example of a network 1130 or network segment 1130 includes, but is not limited to, a wide area network (WAN) (eg, an internet, a corporate network), a local area network (LAN) (eg, and one) An office, a building, a campus or other network associated with a relatively small geographic space, a telephone network, a direct connection between two computing devices, and any combination thereof. For example, the network of the network 1130 can utilize a wired mode and/or a wireless mode of communication. In general, any network topology can be used.

Information and materials can be displayed via a display 1132. An example of a display 1132 includes, but is not limited to, a liquid crystal display (LCD), an organic liquid crystal display (OLED), a cathode ray tube (CRT), a plasma display, and any combination thereof. The display 1132 can be interfaced to the processor 1101, the memory 1103 and the fixed storage 1108, and other devices such as the input device 1133 via the bus 1140. The display 1132 is coupled to the busbar 1140 via a video interface 1122, and data transfer between the display 1132 and the busbar 1140 can be controlled via the mapping control 1121.

In addition to a display 1132, computer system 1100 can include one or more other peripheral output devices 1134, including but not limited to an audio speaker, a printer, and any combination thereof. Such a peripheral output device can be coupled to the busbar 1140 via an output interface 1124. An example of an output interface 1124 includes, but is not limited to, a series of columns, a parallel connection Line, a USB port, a FIREWIRE port, a THUNDERBOLT port, and any combination thereof.

Additionally or alternatively, computer system 1100 can provide functionality that is embodied in a circuit due to fixed line logic or other means that can operate in place of software or in conjunction with software to perform the description herein. Or one or more methods depicted, or one or more steps of one or more methods. References to software in this disclosure may encompass logic, and references to logic may encompass software. Again. A reference to a computer readable medium of a non-transitory entity may, where appropriate, include a circuit for storing software for execution (eg, an IC), a circuit embodying logic for execution, or two By. For example, a non-transitory entity's computer readable medium can cover one or more FPGAs, fixed logic, analog logic, or some combination of the above. The disclosure includes hardware, software, or any suitable combination of the two.

Those skilled in the art will appreciate that information and signals can be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and wafers that may be referenced throughout the above description may be by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or optical particles, or It is any combination of them to represent.

Throughout the specification, the same element symbols are used to indicate terminals, signal lines, wires, and the like, and their corresponding signals. In this regard, the terms "signal", "wire", "wire", "terminal" and "pin" are used interchangeably in this specification. It should also be recognized that the terms "signal", "wire" or the like may represent one or more signals, such as a single bit carried through a single wire, or multiple parallel bits passing through multiple parallel Wire transport Loaded. Furthermore, each wire or signal can represent two-way communication between two or more components connected by a context-specific signal or wire.

Those skilled in the art will further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein can be implemented as electronic hardware, computer software, or a combination of the two. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. The implementation of such functionality as hardware or software is dependent upon the particular application and design constraints imposed on the overall system. A person skilled in the art can implement the described functions in varying ways for each particular application, but the decision of such an embodiment should not be construed as causing a departure from the scope of the invention.

The various illustrated logic blocks, modules, and circuits described in connection with the embodiments disclosed herein may utilize a processor, a digital signal processor (DSP), designed to perform the general purposes of the functions described herein. , a special application integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any of them Combine to implement or execute. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, or microcontroller. A processor can also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other This configuration.

The steps of a method or algorithm described in connection with the embodiments disclosed herein may be directly implemented by hardware, by a software module executed by a processor, by a software module implemented as a digital logic device, Or use a combination of these to reflect. a software module can Exist in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, scratchpad, hard disk, a removable disc, a CD-ROM, or this technology Known in any other form of non-transitory entity in a computer readable storage medium. An exemplary non-transitory physical computer readable storage medium is coupled to the processor such that the processor can read information from the non-transitory entity's computer readable storage medium and write Information to it. In the alternative, the computer readable storage medium of the non-transitory entity may be integral to the processor. The processor and the non-transitory physical computer readable storage medium may reside in an ASIC. The ASIC can reside in a user terminal. In the alternative, the processor and the computer readable storage medium of the non-transitory entity may exist as discrete components in a user terminal. In some embodiments, a software module can be implemented as a digital logic component, such as those in an FPGA once the software module is programmed.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments are obvious to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not intended to be limited to the embodiments shown herein, but the scope of the invention is to be

Claims (16)

A high-speed, high-signal-to-noise, high-gain, and high dynamic range fully differential amplifying circuit for amplifying an optical signal in a pyrometer, the fully differential amplifying circuit comprising: a first system input (304) Is configured to be coupled to an anode of a primary photodetector (302); a second system input (306) configured to be coupled to the primary photodetector ( 302) is a cathode, wherein, when the first and second system input (304, 306) coupled to the main photodetector (302), the current i _p a light-based system in the first and second Passing between inputs (306, 304); a transimpedance differential amplifier stage comprising: a primary bias circuit (308) configured to bias the primary photodetector (302) at 0V Between a reverse bias and having first and second outputs (328, 330); a first transimpedance amplifying circuit (312) having a first current input (316) and a first transimpedance a voltage output (314), wherein: the first current input (316) is coupled to the first system input (304), and a first bias voltage input (318) is coupled A bias circuit connected to the primary (308) the first output (328), the transimpedance and the first output voltage (314) a first voltage line and a current i _p of the light at the proportional; and a The second transimpedance amplifying circuit (320) has a second current input (324) and a second transimpedance voltage output (322), wherein the second current input (324) is coupled to the second a system input (306), a second bias voltage input (326) coupled to the second output (330) of the primary bias circuit (308), and a second voltage transimpedance output (322) a second voltage system is proportional to the photocurrent i _p passing between the second and first system inputs (306, 304); wherein the primary bias circuit (308) is coupled to the first and a second transimpedance amplifying circuit (312, 320), so that a reverse bias voltage to a 0V across present in the main photodetector (302); and a differential output v ₁ major system configured for Converted into a temperature or reflection coefficient value in a processor (210). A fully differential amplifying circuit as claimed in claim 1, further comprising two or more differential voltage amplifier stages (430, 432) each comprising two differential voltage amplifiers arranged in parallel, the two or more differentials Each of the voltage amplifier stages has a differential voltage output v ₂ , v ₃ . A fully differential amplifying circuit as claimed in claim 2, wherein each of the two differential voltage amplifiers in one of the two or more differential voltage amplifier stages (430) is coupled to the transimpedance This differential output of the differential amplifier stage (350). The full differential amplifier circuit of claim 3, wherein a pin of the differential output of the transimpedance differential amplifier stage (350) is coupled to the one of the two or more differential voltage amplifier stages An inverting input of one of the two differential voltage amplifiers (430), and the two differential voltage amplifiers in the one of the two or more differential voltage amplifier stages (430) The other is a non-inverting input, thereby generating twice the gain of a pair of differential amplifiers whose inputs are not inverted. A fully differential amplifier circuit as in claim 2, wherein the two or more differential voltage amplifier stages (430, 432) have different gains. A fully differential amplifier circuit as in claim 5, wherein the two or more differential voltage amplifier stages (430, 432) are configured for coupling to the processor having a software selector (208) (210), the software selector (208) is configured to select between outputs of the two or more differential voltage amplifier stages (430, 432) such that selection of amplification gain can be during data collection It is executed without using a mechanical switch, and therefore the data stream does not need to be seamed. The full differential amplification circuit of claim 1, further comprising a blind stage, the blind stage comprising: a blind light detector, which is associated with most of the photons seen by the primary light detector Radiation isolation, but identical in structure to the primary photodetector; a blind bias circuit coupled to a third transimpedance amplifier circuit (512) and a fourth transimpedance amplifier circuit (520) a voltage input (518, 526) and configured to bias the blind photodetector (502) with a bias equal to the magnitude of the bias across the primary photodetector (302), wherein the photodetector blind system on behalf of the main photodetector (302) is a leakage current; and a blind differential output v _4, which system is to be configured for the primary differential output from subtracting v _1. A fully differential amplifying circuit as in claim 7 further comprising a pair of comparators (554, 556) each having a pair of inputs coupled to the primary differential voltage output v ₁ and the blind differential a voltage output v ₄ , the comparators (554, 556) having a polarity such that a differential output v ₅ of the pair of comparators (554, 556) is equal to the primary differential output v ₁ and the blind differential output v ₄ A difference between. The fully differential amplifying circuit of claim 1, further comprising: a first switch (328) selectively coupling the first system input (304) to the first transimpedance amplifying circuit (312) The first current input (316); and a conductive loop (360) between the first and second system inputs (304, 306), the conductive loop (360) comprising a selectivity Grounding a second switch (330) of the first and second system inputs (304, 306), wherein the first switch and the second open relationship are alternately switched such that the primary photodetector (302) is The full differential amplification circuit is selectively switched out, whereby the correction of the allowable leakage current can be performed when the primary photodetector (302) is not present. A pyrometer system comprising: a primary photodetector (201); a dual differential amplifier circuit (202) comprising a pair of transimpedance amplifiers coupled to the main optical detector detector (201), and having a photocurrent i proportional to the differential voltage of the two _p outputs (212, 214) generated by the main photodetector (201), but with different gain; a first analog-to a digital converter (204) coupled to a first differential voltage output of the two differential voltage outputs (212) and configured to convert a first differential voltage output (212) to a corresponding digital value, And having a first digital output (216) providing the corresponding digital value to a processor (210); a second analog to digital converter (206) coupled to the two differential voltage outputs (204) a second differential voltage output, and configured to convert a second differential voltage output (214) to a corresponding digit value, and having a second digit providing the corresponding digit value to the processor (210) An output (218); and the processor (210) coupled to the first a binary output (216, 218) having a selector (208) coupled to the first and second digital outputs (216, 218) and configured to select the first Which of the second digit outputs (216, 218) will be processed by the processor, the processor (210) being configured to convert a selected one of the first and second digit outputs (216, 218) The person becomes a temperature or reflection coefficient value and has an output (220) that provides the temperature or the value of the reflection coefficient. A pyrometer system according to claim 10, wherein the dual differential amplifier circuit (202) includes a primary bias circuit configured to cause a bias voltage on the primary photodetector 201, wherein The bias can range from 0V to a reverse bias. A method of operating a dual fully-differential amplification method circuits, which system comprises: a light-receiving current i _p, i _p of the photocurrent by a photodetector to a primary differential transimpedance differential amplifier stage (350), which system comprises the transimpedance amplifying circuit (312,320) a first pair of parallel configuration; differential transimpedance via the differential amplifier stage (350) to convert the light into a current i _p differential output voltage v _1; providing the first differential output voltage v ₁ to a pair of differential voltage amplifier stages (430, 432) arranged in parallel, thereby converting the first differential output voltage v ₁ into a pair of second and third differential output voltages v ₂ and v ₃ having different gains; Providing the second and third pairs of differential output voltages v ₂ and v ₃ to a processor via a pair of analog to digital converters (204, 206); selecting the second and third differential output voltages v ₂ and v ₃ One of them is used for processing without a mechanical switch; converting one of the second and third differential output voltages v ₂ and v ₃ to a temperature or a reflection coefficient value. The method of claim 12, further comprising: receiving a dark offset current i _d , the blind offset current i _d passing through a blind photodetector to a blind stage (350), the blind stage (350) a second pair of transimpedance amplifying circuits (512, 520) arranged in parallel; via the differential transimpedance differential amplifier stage (350) to convert the dark offset current i _d into a fourth differential output voltage v ₄ , The blind light detector represents a leakage current in the primary photodetector; the fourth differential output voltage v _{4 is} subtracted from the first differential output voltage v ₁ to form a fifth differential output voltage v _5; and providing the differential output voltage V to the ₅ V voltage for the differential amplifier stage (430, 432); converting the fifth differential output voltage V ₅ becomes the second and third differential output voltage v ₂ and v _3; And converting one of the second and third differential output voltages v ₂ and v ₃ to a temperature or a reflection coefficient value, the subtracting system utilizing the dark offset current i _d to consider the primary optical detection Leakage current in the detector. The method of claim 12, further comprising: selectively removing the primary photodetector and the blind photodetector from the fully differential dual amplifying circuit; without the influence of the primary photodetector Determining an offset current in the fully differential dual amplifying circuit; and subtracting the offset current from the primary photocurrent i _p , the primary photocurrent i _{p being} based on the second or third differential output voltage v ₂ and v The subtraction is determined by the selector in ₃ , and the subtraction occurs in the processor. For example, the method of claim 12, further comprising: utilizing A primary bias between the reverse bias is included to bias the primary photodetector and bias the blind photodetector with a blind bias of the same magnitude but opposite polarity. The method of claim 12, further comprising: biasing the primary photodetector with a primary bias between 0V and a reverse bias, and utilizing the magnitude of the primary bias And a blind bias of the same polarity to bias the blind photodetector.