CN107517354B - Infrared focal plane reading circuit and feedback control loop thereof - Google Patents
Infrared focal plane reading circuit and feedback control loop thereof Download PDFInfo
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Abstract
The invention discloses an infrared focal plane reading circuit and a feedback control loop thereof, wherein the infrared focal plane reading circuit comprises a reading circuit unit and a feedback control loop, and the reading circuit unit comprises an integral amplification circuit; the integral amplifying circuit outputs integral voltage; the feedback control loop comprises a voltage comparator F1, a counting control module and a control switch, wherein the voltage comparator F1 compares the integrated voltage with a reference voltage Vcomp and outputs the comparison result to the counting control module; the counting control module counts according to a comparison result output by the voltage comparator F1, outputs a count value N and outputs a pulse signal to the control switch when the count value N changes; one end of the control switch is connected with the output end of the integral amplifying circuit and the fixed potential VrefTo (c) to (d); and the on and off of the control switch is controlled by the pulse signal output by the counting control module. The invention achieves the purpose of expanding the circuit structure of the high-temperature detection range by carrying out segmentation processing integration through the special control of the feedback control loop.
Description
Technical Field
The invention relates to an infrared focal plane reading circuit, in particular to an infrared focal plane reading circuit and a feedback control loop thereof.
Background
The infrared focal plane array is a core photoelectric device for acquiring infrared image signals in an infrared imaging technology, integrates infrared photoelectric conversion and signal processing, and is a high-performance infrared solid image sensor. The infrared focal plane array mainly comprises an infrared detector array and a reading circuit, wherein the detector is used for converting infrared radiation into an electric signal, and the reading circuit is used for carrying out preprocessing (such as integration, amplification, filtering, sampling/holding, parallel/serial conversion and the like) and A/D conversion on a weak infrared electric signal sensed by the detector.
The function of a conventional readout circuit of an infrared focal plane is to bias a pixel in the infrared focal plane, and convert, amplify and output a pixel signal for imaging at the back end.
However, the detection range of the traditional infrared focal plane reading circuit is limited by temperature, so that the detection range which can be read by the reading circuit is narrow, the use of the reading circuit in certain high-temperature occasions is limited, and the problem that the use of the reading circuit in the prior art is limited in certain high-temperature occasions is solved.
Disclosure of Invention
The invention aims to provide an infrared focal plane reading circuit and a feedback control loop thereof, wherein the infrared focal plane reading circuit has an infrared focal plane reading circuit structure capable of expanding a high-temperature detection range, so that the circuit can acquire signals in a wider temperature range, and the problem that the reading circuit in the prior art is limited in use in certain high-temperature occasions is solved.
The invention is realized by the following technical scheme:
an infrared focal plane readout circuit comprises a readout circuit unit, wherein the readout circuit unit comprises an integral amplification circuit and a feedback control loop; the integral amplifying circuit is connected with the infrared detection signal, integrates the infrared detection signal and outputs an integral voltage Vout; the feedback control loop comprises a voltage comparator F1, a count control module CO and a control switch S, wherein:
the voltage comparator F1 compares the integration voltage Vout output by the integration amplifying circuit with the reference voltage Vcomp, and outputs the comparison result to the count control module CO;
the counting control module CO counts according to a comparison result output by the voltage comparator F1, outputs a counting value N and outputs a pulse signal to the control switch S when the counting value N changes;
one end of the control switch S is connected with the output end of the integral amplifying circuit, and the other end of the control switch S is connected with a fixed potential Vref(ii) a And the on and off of the control switch S is controlled by a pulse signal output by the counting control module CO.
In the technical scheme, a feedback control loop is added in a traditional reading circuit and comprises a voltage comparator F1, a counting control module CO and a logic control switch S, one end of the control switch S is connected with the output end of an integral amplifying circuit, and the other end of the control switch S is connected with a fixed potential VrefThereby providing a V to the integral amplifying circuitrefA path from the control switch S to the integral amplifying circuit; the on and off of the control switch S are controlled by a pulse signal output by the counting control module CO; when the control switch S is closed, the output end of the integral amplifying circuit and the fixed potential VrefConducting; when the control switch S is turned off, the output end of the integral amplifying circuit and the fixed potential VrefDisconnect so that when the count control module is at VoutValue of greater than VcompWhen the circuit is started, the counting part of the counting control module CO outputs the turnover frequency N and outputs a logic level, the logic level is connected with the control switch S, so that the control switch S is closed temporarily, the output of the integral amplifying circuit is pulled down to Vref, and signal detection in one period is completed; after the pulse signal is finished, the integral amplification circuit starts to collect and integrate the signal again, the process is repeated, the signal is collected and integrated for many times, and accumulated and counted for many times, so that the sampling signal after the high-temperature detection range is expanded can be obtained, and the integration is processed in a segmented mode through special control of a feedback control loop, so that the purpose of expanding the circuit structure of the high-temperature detection range is achieved.
As a further improvement of the present invention, an inverting input terminal of the voltage comparator F1 is connected to an output terminal of the integrating and amplifying circuit, a forward input terminal is connected to the reference voltage signal Vcomp, and an output terminal is connected to an input terminal of the counting control module CO.
As a further improvement of the present invention, the integrating and amplifying circuit includes an integrating amplifier F2 and a capacitor C; the positive input end of the integrating amplifier F2 is connected with a fixed potential Vref, the reverse input end is connected with an infrared detection signal, and the output end is connected with the reverse input end of the voltage comparator F1 and outputs an integrating voltage Vout; the capacitor C is connected between the inverting input terminal and the output terminal of the integrating amplifier F2.
Further, the feedback control loop also comprises a reference voltage unit circuit for providing a reference voltage signal, wherein the output end of the reference voltage unit circuit is connected with the positive input end of the voltage comparator F1, and the infrared detection signal is output to the integral amplifying circuit.
Preferably, the readout circuit unit is a column-level integrated readout circuit.
Furthermore, the infrared focal plane reading circuit further comprises a fixed potential branch circuit for providing a fixed potential Vref, and the output end of the fixed potential branch circuit is simultaneously connected with the other end of the control switch S and the integral amplification circuit.
Furthermore, the readout circuit unit further comprises a signal bias circuit, and an output end of the signal bias circuit is connected with an input end of the integrating and amplifying circuit.
A feedback control loop of an infrared focal plane readout circuit, the feedback control loop being connected to an output of a readout circuit unit of the infrared focal plane readout circuit, the feedback control loop comprising a voltage comparator F1, a count control module CO and a control switch S, wherein:
the voltage comparator F1 compares the voltage output by the readout circuit unit with the reference voltage Vcomp, and outputs the comparison result to the count control module CO;
the counting control module CO counts according to a comparison result output by the voltage comparator F1 to output a counting value N, and outputs a pulse signal to the control switch S when the counting value N changes;
one end of the control switch S is connected with the output end of the reading circuit unit, and the other end of the control switch S is connected with a fixed potential Vref(ii) a And the on and off of the control switch S is controlled by a pulse signal output by the counting control module CO.
Further, the reverse input end of the voltage comparator F1 is connected to the output end of the readout circuit unit, the forward input end is connected to the reference voltage Vcomp, and the output end is connected to the count control module CO.
Preferably, the feedback control loop further comprises a reference voltage unit circuit for providing a reference voltage signal, an output terminal of the reference voltage unit circuit being connected to a positive input terminal of the voltage comparator F1.
Compared with the prior art, the invention has the following advantages and beneficial effects: the infrared focal plane reading circuit adds a feedback control loop in the traditional reading circuit, the feedback control loop comprises a voltage comparator F1, a counting control module CO and a logic control switch S, one end of the control switch S is connected with the output end of the integral amplifying circuit, and the other end is connected with a fixed potential VrefThereby providing a Vref for the integrating and amplifying circuit, controlling the passage of the switch S to the integrating and amplifying circuit; the on and off of the control switch S are controlled by a pulse signal output by the counting control module CO; when the control switch S is closed, the output end of the integral amplifying circuit and the fixed potential VrefConducting; when the control switch S is turned off, the output end of the integral amplifying circuit and the fixed potential VrefDisconnect so that when the count control module is at VoutValue of greater than VcompWhen the circuit is started, the counting part of the counting control module CO outputs the turnover frequency N and outputs a logic level, the logic level is connected with the control switch S, so that the control switch S is closed temporarily, the output of the integral amplifying circuit is pulled down to Vref, and signal detection in one period is completed; after the pulse signal is finished, the integral amplification circuit starts to collect and integrate the signal again, the process is repeated, the signal is collected and integrated for many times, and accumulated and counted for many times, so that the sampling signal after the high-temperature detection range is expanded can be obtained, and the integration is processed in a segmented mode through special control of a feedback control loop, so that the purpose of expanding the circuit structure of the high-temperature detection range is achieved.
Drawings
The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:
figure 1 is a circuit diagram of an infrared focal plane readout circuit in one embodiment of the invention;
fig. 2 is a comparison diagram of voltage waveforms output by the readout circuit unit before and after the detection range is expanded in the infrared focal plane readout circuit in an embodiment of the present invention.
Reference numbers and corresponding part names: 10-sense circuit unit, 20-feedback control loop.
Detailed Description
In long-term research, the inventors found that: in the prior art, the detection range of a traditional infrared focal plane reading circuit is limited by temperature, so that the detection range which can be read by the reading circuit is narrow, the use of the reading circuit in certain high-temperature occasions is limited, and the requirement of expanding a high-temperature detection range circuit exists.
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that: it is not necessary to employ these specific details to practice the present invention. In other instances, well-known structures, circuits, materials, or methods have not been described in detail so as not to obscure the present invention.
[ example 1 ]
As shown in fig. 1, an infrared focal plane readout circuit of the present invention includes a readout circuit unit 10 and a feedback control loop 20.
The readout circuit unit 10 includes a signal bias circuit and an integrating and amplifying circuit; the signal bias circuit outputs an infrared detection signal to the integral amplification circuit; the integral amplifying circuit comprises an integral amplifier F2 and a capacitor C; the positive input end of the integrating amplifier F2 is connected with a fixed potential Vref, the negative input end is connected with a signal bias circuit so as to access an infrared detection signal, and the output end outputs an integrating voltage Vout; the capacitor C is connected between the reverse input end and the output end of the integrating amplifier F2, so that the integrating amplifying circuit is connected with the infrared detection signal, integrates the infrared detection signal and outputs an integrating voltage Vout;
the feedback control loop 20 comprises a voltage comparator F1, a count control module CO and a control switch S, wherein:
the inverting input end of the voltage comparator F1 is connected with the output end of the integrating and amplifying circuit, the positive input end of the voltage comparator F1 is connected with a reference voltage signal Vcomp, and the output end of the voltage comparator F1 is connected with the input end of the counting control module CO. The voltage comparator F1 thus compares the integration voltage Vout output by the integration amplification circuit with the reference voltage Vcomp, and outputs the comparison result to the count control module CO. The output terminal of the integrating and amplifying circuit is the output terminal of the integrating amplifier F2, and is also the output terminal of the readout circuit unit 10.
The counting control module CO counts according to a comparison result output by the voltage comparator F1, outputs a counting value N and outputs a pulse signal to the control switch S when the counting value N changes;
one end of the control switch S is connected with the output end of the integral amplifying circuit, and the other end of the control switch S is connected with a fixed potential Vref(ii) a The on and off of the control switch S are controlled by a pulse signal output by the counting control module CO; when the control switch S is closed, the output end of the integral amplifying circuit and the fixed potential VrefConducting; when the control switch S is turned off, the output end of the integral amplifying circuit and the fixed potential VrefThe connection is broken.
In this embodiment, the expansion of the high temperature detection range of the conventional infrared focal plane readout circuit is realized by adding a feedback control loop 20 to the conventional readout circuit, where the feedback control loop 20 includes a voltage comparator F1, a count control module CO, and a logic control switch S. The inverting input terminal of the voltage comparator F1 and the output terminal V of the integrating amplifier F2outConnected to a fixed potential V at the same timerefThe branch is connected with the normal phase input end and the reference level VcompAnd the output end of the counting control module is connected with the input end of the counting control module CO. The input end of the counting control module CO is connected with the output end of the voltage comparator F1, and the counting control module CO outputs high levelThe number of the switch S outputs a count value N, and the control logic controls the on and off of the switch S through a series of logics so as to control and connect a fixed potential VrefOn or off of the branch. One end of the control switch S is connected with a fixed potential VrefAnd the other end is connected to the output of the integrating amplifier F2.
The counting control module is in VoutValue of greater than VcompDuring the process, the counting part of the counting control module CO outputs the turnover number N and simultaneously outputs a logic level, and the logic level is connected with the control switch S, so that the control switch S is closed temporarily.
The operation principle of the infrared focal plane readout circuit of the present embodiment is briefly described below.
In the embodiment shown in fig. 1, the signal bias circuit charges the inverting input terminal of the integrating amplifier F2, and since the voltage across the capacitor C cannot change abruptly, the potential at the output terminal of Vout increases linearly with the charging time. When the potential of Vout rises to be higher than the potential Vcomp of the positive input end of the voltage comparator F1, the voltage comparator F1 outputs high level and inputs the high level into the counting control module CO; the counting control module CO receives the high level output by the voltage comparator F1, then the value of the counting value N is added by 1, then the counting control module CO outputs the times N of the high level output by the voltage comparator, simultaneously outputs a high and narrow pulse level, the logic control switch S is conducted at the high level, and the output end potential of the integrating amplifier F2 is instantly pulled to VrefThe discharge time of the process is negligible. After the narrow pulse potential is finished, the signal bias circuit starts to collect and integrate the signals again, the process is repeated, the signals are collected and integrated for multiple times, and the signals are accumulated and counted for multiple times, so that the sampling signals after the detection range is expanded at high temperature can be obtained.
In this embodiment, the counting control module CO includes a counting module and a pulse signal output module, the counting module is connected to an output end of the voltage comparator F1, and is configured to count and output a count value N and output a control signal to the pulse signal output module when receiving a high level output by the voltage comparator F1, and the pulse signal output module sends a narrow pulse signal (pulse width can be ignored in subsequent calculations) to the control switch S when receiving the control signal.
In other embodiments, the count control module CO may also output a low and narrow pulse level by adding 1 to the value of the count value N after receiving the high level output by the voltage comparator F1, and correspondingly, the logic control switch S is turned on at the low level.
In this embodiment, the control switch S may be, but is not limited to, a relay, a transistor, and the like. The control end (for example, the contact of the relay and the base of the triode) of the control switch S is connected with the counting control module CO, so that the switch is turned on or off under the control of the pulse signal of the counting control module CO, and the setting of the control switch S belongs to the prior art, which is not described in detail in this embodiment.
Fig. 2 is a comparison graph of voltage waveforms output by the readout circuit unit before and after the detection range is expanded, in fig. 2, the abscissa is the temperature Temp, and the ordinate is the voltage value.
As shown in fig. 2, in the prior art, for the read value before expanding the detection range, within the readable temperature range, there is a linear relationship of Vout ═ a Temp + B, where a and B are constants, and when the temperature is higher and exceeds the maximum detectable temperature T1, Vout reaches saturation and does not rise any more, so that the high temperature range cannot be effectively detected. However, the infrared focal plane readout circuit in this embodiment may expand the detectable temperature thereof by performing repeated charging and discharging processing on the output result of the integrating amplifier F2, and effectively obtain the detection value exceeding the temperature T1, which corresponds to the actual voltage value V when the temperature is T2OUTIs calculated as follows:
VOUT＝N*(Vcomp-Vref)+Vout(1)
wherein N represents the number of times of high level output by the comparator after the accumulation of the count control module, Vcomp represents the reference voltage at the inverting input terminal of the voltage comparator F1, Vref is the reference potential at the output terminal of the integrating amplifier F2, and Vout represents the current output value of the integrating amplifier. Thus, by calculating the equation (1), V in the case where the temperature T1 is exceeded can be calculatedOUTThe detection range is greatly expanded. In the prior art, the voltage between two ends of a capacitor C in an integral amplifying circuit cannot be suddenly changedAlternatively, the processed signal (infrared detection signal) is integrated. The inverting input terminal of the voltage comparator F1 in the feedback control loop 20 is connected to the output terminal of the integrating amplifier F2 and is connected to the fixed potential VrefThe branch is connected with the capacitor C charged by the processed signal, VoutThe voltage rises, and the detection range of the integral amplifying circuit is limited by the charge storage capacity and the temperature of the capacitor C, so that the integral amplifying circuit is narrow. In this embodiment, the integration is processed in a segmented manner by special control of the feedback control loop 20, so as to achieve the purpose of expanding the circuit structure of the high-temperature detection range.
[ example 2 ]
On the basis of embodiment 1, the following modifications are also made to the feedback control loop in this embodiment:
the feedback control loop 20 further comprises a reference voltage unit circuit for providing a reference voltage signal, an output terminal of the reference voltage unit circuit being connected to a positive input terminal of the voltage comparator F1. In this embodiment, the reference voltage unit circuit includes a power supply and two resistors connected in series, the two resistors are connected in series between the power supply and the ground, a common terminal of the two resistors is an output terminal of the reference voltage unit circuit, and a positive input terminal of the voltage comparator F1 is connected to the common terminal of the two resistors.
[ example 3 ]
In addition to embodiment 1 or embodiment 2, the present embodiment further improves the infrared focal plane readout circuit as follows:
the infrared focal plane reading circuit further comprises a fixed potential branch circuit used for providing a fixed potential Vref, and the output end of the fixed potential branch circuit is simultaneously connected with the other end of the control switch S and the integral amplification circuit.
[ example 4 ]
On the basis of embodiment 1, the following modifications are also made to the feedback control loop in this embodiment:
the feedback control loop also comprises a fixed potential branch circuit used for providing a fixed potential Vref, and the output end of the fixed potential branch circuit is simultaneously connected with the other end of the control switch S and the integral amplification circuit.
As can be seen from embodiments 3 and 4, the fixed potential branch is used to provide a fixed potential to the output and the positive input of the voltage comparator F1, which may be located in a feedback control loop or separately in the infrared focal plane readout circuit.
In practice, the fixed potential branch comprises a voltage source connected to both the output of the voltage comparator F1 and the other end of the control switch S.
[ example 5 ]
On the basis of any of the above embodiments, the following improvements are also made to the feedback control loop in this embodiment:
the readout circuit unit 10 adopts a column-level integrated readout circuit, which is also called a column-level readout circuit.
In fig. 1, the signal bias circuit includes a converter VDAC1And VDAC2MOS transistor M1MOS transistor M2Pixel resistance RsAnd a blind pixel resistor Rb. Converter VDAC1The output end of the MOS transistor is connected with an MOS transistor M2Grid of (2), converter VDAC2The output end of the MOS transistor is connected with an MOS transistor M1The grid of (1), the blind pixel resistor RbMOS transistor M2MOS transistor M1Pixel resistance RsSequentially connected in series; pixel resistance RsOne end is grounded, and the other end is connected with an MOS (metal oxide semiconductor) transistor M1Flows through the pixel resistor RsHas a current of Is(ii) a Blind pixel resistor RbOne end of the connection is connected with a voltage VSKThe other end is connected with a MOS tube M2Through a blind pixel resistor RbHas a current of Ib. Integrating amplifier F2Is connected with the MOS tube M2And MOS transistor M1On the common terminal.
The column-level readout circuit in this embodiment is constituted by an on-chip DAC (converter V)DAC1And VDAC2) Controlling the corresponding bias MOS transistor (M)2And M1) Therefore, the bias state of the pixel (or the blind pixel) is adjusted, on-chip non-uniformity correction is realized, and the structure of the traditional reading circuit is provided. Thus, the readout circuit unit 10 in this embodiment applies a voltage to the gate terminal of the CMOS transistor by applying a different bias voltage to each pixel, and applies a voltage to the image thermally isolated from the substrateElement resistor RsBranch and blind pixel resistor R thermally short-circuited with substratebThe current comparison of the branches samples the charge of the capacitor C of the integrating amplifier F2.
The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (10)
1. An infrared focal plane readout circuit comprising a readout circuit unit (10), said readout circuit unit (10) comprising an integrating amplification circuit; the integral amplifying circuit is connected with the infrared detection signal, integrates the infrared detection signal and outputs an integral voltage Vout; the infrared focal plane reading circuit is characterized by further comprising a feedback control loop (20);
the feedback control loop (20) comprises a voltage comparator F1, a count control module CO and a control switch S, wherein:
the voltage comparator F1 compares the integration voltage Vout output by the integration amplifying circuit with the reference voltage Vcomp, and outputs the comparison result to the count control module CO;
the counting control module CO counts according to a comparison result output by the voltage comparator F1, outputs a counting value N and outputs a pulse signal to the control switch S when the counting value N changes;
one end of the control switch S is connected with the output end of the integral amplifying circuit, and the other end of the control switch S is connected with a fixed potential Vref(ii) a The on and off of the control switch S are controlled by a pulse signal output by the counting control module CO; the counting control module CO comprises a counting module and a pulse signal output module, the counting module is connected with the output end of the voltage comparator F1, when the electric potential of Vout rises to be higher than the electric potential Vcomp of the positive input end of the voltage comparator F1, the voltage comparator F1 outputs high level, and the counting control module is inputManufacturing a module; the counting module adds 1 to the high-level timer value N output by the voltage comparator F1 and outputs a counting value N and a control signal to the pulse signal output module, when the pulse signal output module receives the control signal, the pulse signal output module sends a narrow pulse signal to the control switch S to close the control switch S, and the output end of the integral amplifying circuit and the fixed potential V are connectedrefConducting, and pulling down the output of the integral amplifying circuit to Vref; after the pulse signal is finished, the control switch S is switched off, and the output end of the integral amplifying circuit is connected with the fixed potential VrefAnd when the connection is disconnected, the integral amplification circuit starts to collect the integral of the infrared detection signal again.
2. The infrared focal plane readout circuit of claim 1, wherein the inverting input terminal of the voltage comparator F1 is connected to the output terminal of the integrating and amplifying circuit, the forward input terminal is connected to the reference voltage signal Vcomp, and the output terminal is connected to the input terminal of the count control module CO.
3. An infrared focal plane readout circuit as claimed in claim 2 wherein said integrating amplifier circuit comprises integrating amplifier F2 and capacitor C; the positive input end of the integrating amplifier F2 is connected with a fixed potential Vref, the reverse input end is connected with an infrared detection signal, and the output end is connected with the reverse input end of the voltage comparator F1 and outputs an integrating voltage Vout; the capacitor C is connected between the inverting input terminal and the output terminal of the integrating amplifier F2.
4. An infrared focal plane readout circuit as claimed in claim 3 wherein said feedback control loop (20) further comprises a reference voltage unit circuit for providing a reference voltage signal, an output of the reference voltage unit circuit being connected to a positive input of a voltage comparator F1.
5. An infrared focal plane readout circuit according to any of claims 1 to 4, characterized in that the readout circuit unit (10) is a column-level integrated readout circuit.
6. An infrared focal plane readout circuit according to any of claims 1 to 4, further comprising a fixed potential branch for providing a fixed potential Vref, wherein the output terminal of the fixed potential branch is connected to both the other terminal of the control switch S and the integrating amplifier circuit.
7. The infrared focal plane readout circuit according to any one of claims 1 to 4, wherein the readout circuit unit (10) further comprises a signal bias circuit, an output terminal of the signal bias circuit is connected to an input terminal of the integrating amplifier circuit, and the signal bias circuit outputs the infrared detection signal to the integrating amplifier circuit.
8. A feedback control loop for an infrared focal plane readout circuit, said feedback control loop being connected to an output of a readout circuit unit (10) of the infrared focal plane readout circuit, said feedback control loop comprising a voltage comparator F1, a count control module CO and a control switch S, wherein:
the voltage comparator F1 compares the voltage output by the reading circuit unit (10) with a reference voltage Vcomp and outputs the comparison result to the counting control module CO;
the counting control module CO counts according to a comparison result output by the voltage comparator F1 to output a counting value N, and outputs a pulse signal to the control switch S when the counting value N changes;
one end of the control switch S is connected with the output end of the reading circuit unit (10), and the other end is connected with a fixed potential Vref(ii) a The on and off of the control switch S are controlled by a pulse signal output by the counting control module CO; the counting control module CO comprises a counting module and a pulse signal output module, the counting module is connected with the output end of the voltage comparator F1, when the potential of Vout rises to be higher than the potential Vcomp of the positive input end of the voltage comparator F1, the voltage comparator F1 outputs high level and inputs the high level into the counting control module; the counting module counts the number of times when receiving the high level output from the voltage comparator F1The value of the value N is added with 1, a count value N is output, a control signal is output to the pulse signal output module, when the pulse signal output module receives the control signal, a narrow pulse signal is sent to the control switch S to enable the control switch S to be closed, and the output end of the integral amplification circuit and the fixed potential V are connectedrefConducting, and pulling down the output of the integral amplifying circuit to Vref; after the pulse signal is finished, the control switch S is switched off, and the output end of the integral amplifying circuit is connected with the fixed potential VrefAnd when the connection is disconnected, the integral amplification circuit starts to collect the integral of the infrared detection signal again.
9. The feedback control loop of an infrared focal plane readout circuit according to claim 8, wherein the inverting input terminal of the voltage comparator F1 is connected to the output terminal of the readout circuit unit (10), the forward input terminal is connected to the reference voltage Vcomp, and the output terminal is connected to the count control module CO.
10. The feedback control loop of an infrared focal plane readout circuit as set forth in claim 9, wherein said feedback control loop (20) further comprises a reference voltage unit circuit for providing a reference voltage signal, an output of the reference voltage unit circuit being connected to a positive input of the voltage comparator F1.
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| WO2020250846A1 (en) * | 2019-06-13 | 2020-12-17 | 住友電気工業株式会社 | Optical reception device, station-side device, pon system, preamplifier, optical reception method, and method for suppressing output inversion of integrator |
| CN116972981B (en) * | 2023-07-31 | 2024-02-20 | 无锡物联网创新中心有限公司 | Readout method and readout device of thermopile sensor |
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