Readout circuit for time-sharing readout quantization, analog-to-digital converter, and electronic device

Abstract

The invention discloses a readout circuit for time-sharing readout quantization, an analog-to-digital converter and electronic equipment, and relates to the field of integrated circuits. Comprising a plurality of sampling units and a plurality of quantization units which are arranged in a column-level circuit. Each sampling unit in the plurality of sampling units is connected with each wide row in the pixel array in a one-to-one correspondence manner; each column in the column-level circuit is correspondingly provided with a quantization unit and a plurality of sampling units, and the number of the sampling units correspondingly arranged in each column is the same as the row number in the wide row; wherein in each wide row time, pixel signals of each row corresponding to a wide row on a column are read into the sampling unit of the column in a time-sharing manner, and then the quantization unit arranged in the column is used for quantization in the next quantization time. According to the invention, serial transfer of a plurality of analog voltages and parallel conversion of the analog-to-digital converter are adopted, so that the quantization time of each row is greatly extended, the condition that the quantization time is limited is well relieved, and the purpose that the infrared detector completes high-speed accurate reading with relatively low power consumption is achieved.

Description

Technical Field

[0001] This application relates to the field of integrated circuits, and more specifically, to a time-division readout quantization readout circuit, an analog-to-digital converter, and an electronic device. Background Technology

[0002] Currently, most infrared detectors, especially short- and mid-wave detectors, use column-level analog-to-digital converters (ADCs) for their readout circuits. Traditional large-scale pixel arrays perform ADCs at the column level, quantizing each row sequentially before outputting the data for each row. This results in very short quantization times for each row, severely limiting quantization performance.

[0003] When quantization time is limited, higher power consumption is required to achieve high-speed and accurate readout, which obviously contradicts the overall demand for low-power infrared detectors. Therefore, there is an urgent need to propose a pixel array readout circuit that is low-power and has a relatively sufficient quantization time. Summary of the Invention

[0004] In view of the above problems, this application proposes a time-division readout quantization readout circuit, analog-to-digital converter, and electronic device to overcome the shortcomings of the prior art.

[0005] This application provides a time-division multiplexing quantization readout circuit, including: multiple sampling units and multiple quantization units arranged in a column-level circuit; Each sampling unit in the multiple sampling units is connected one-to-one with each row of the wide row in the pixel array, where the wide row is composed of one or more rows in the pixel array; In the column-level circuit, each column corresponds to one quantization unit and multiple sampling units, and the number of sampling units in each column is the same as the number of rows in the wide row. In each wide row time interval, the pixel signal of each row corresponding to the wide row in a column is read out in time-division multiplexing into the sampling unit of that column, and then quantized using the quantization unit deployed in that column in the next quantization time interval.

[0006] Optionally, when there are T rows in the wide row, the wide row time is divided into T small time segments t. In each small time segment t, the pixel signal of one row in the wide row is read into the sampling unit corresponding to that row. After T small time segments t, the pixel signals of all rows in the wide row are obtained.

[0007] Optionally, after reading the pixel signals of all rows in the wide row within the current wide row time, the quantization unit deployed in each column quantizes the pixel signals of all rows in the wide row read within the current wide row time in the next wide row time. The quantization time of the quantization unit is equal to the wide row time.

[0008] Optionally, each of the sampling units includes: a readout subunit and a storage subunit; The input terminal of the readout subunit is connected to one row of the wide row, and the output terminal is connected to the input terminal of the storage subunit. The readout subunit is used to sample and read out the pixel signal of the corresponding row. The output terminal of the storage sub-unit is connected to the input terminal of the target quantization unit, which is the quantization unit deployed in the column where the storage sub-unit is located.

[0009] Optionally, the readout subunit includes at least one sampling capacitor.

[0010] Optionally, each of the quantization units includes: at least one quantization subunit and one conversion subunit; The number of quantization sub-units is the same as the number of sampling units deployed in the same column. The input terminal of each quantization sub-unit is connected to the output terminal of each sampling unit deployed in the same column in a one-to-one correspondence. Each quantization sub-unit is used to quantize the pixel signal it receives. The output of all quantization subunits is connected to the conversion subunit, which is used to convert the quantization results of all quantization subunits to obtain the quantization result corresponding to the column.

[0011] Optionally, the wide row time = max(the sum of the sampling and readout times of N / n sampling units and the quantization time of the quantization unit), where N represents the total number of rows in the pixel array and n represents the number of wide rows.

[0012] Optionally, the row time of each row in the wide row is equal to the sampling and readout time of the corresponding sampling unit in that row. This application provides an analog-to-digital converter, which includes a readout circuit with time-division readout quantization as described in any of the preceding claims.

[0013] This application provides an electronic device, which includes a readout circuit with time-division readout quantization as described in any of the preceding claims.

[0014] The time-division multiplexing readout quantization circuit proposed in this application includes: multiple sampling units and multiple quantization units arranged in a column-level circuit. Each sampling unit is connected one-to-one with each row of a wide row in the pixel array, where a wide row consists of one or more rows in the pixel array.

[0015] In the column-level circuit, each column corresponds to one quantization unit and multiple sampling units. The number of sampling units in each column is the same as the number of rows in the wide row. Specifically, during each wide row time interval, the pixel signal of each row corresponding to the wide row in a column is read out in a time-division multiplexing manner into the sampling unit of that column, and then quantized using the quantization unit deployed in that column during the next quantization time interval.

[0016] This application creatively proposes a time-division multiplexing quantization readout circuit, which differs from the traditional method of sequentially quantizing each row and then outputting data row by row during analog-to-digital conversion in large-scale pixel arrays. Instead, it divides the pixel array into multiple wide rows, and within each wide row's time interval, reads the pixel signal of each row into the sampling unit of that column in a time-division multiplexing manner. Since the transfer time of analog voltage is much shorter than the quantization time of the analog-to-digital converter, multiple analog voltages are serially transferred, and then the analog-to-digital converter can convert them in parallel. This greatly extends the quantization time of each row, effectively alleviating the limitation of quantization time. This achieves the goal of high-speed and accurate readout of infrared detectors, especially short- and mid-wave detectors, with low power consumption, and has broad application prospects and high practicality. Attached Figure Description

[0017] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a modular schematic diagram of a time-division multiplexing readout quantization readout circuit according to an embodiment of this application; Figure 2 This is a schematic diagram of the structure of column-level circuit 1, one of the M column circuits in the embodiments of this application; Figure 3 This is a graph showing the relationship between the quantization time TADC and the sampling time TSH (i.e., the sampling and readout time) for column 1 in this embodiment of the application. Figure 4 This is a schematic diagram illustrating the structure of a preferred sampling unit exemplified in the embodiments of this application; Figure 5 This is a schematic diagram of a preferred quantization unit structure exemplified in the embodiments of this application. Detailed Implementation

[0018] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain this application, and are merely some embodiments of this application, not all embodiments, and are not intended to limit this application.

[0019] This application provides a time-division multiplexing readout quantization readout circuit, referring to... Figure 1 The modular schematic diagram shown includes multiple sampling units and multiple quantization units arranged in a column-level circuit. For example... Figure 1 The readout circuit pixel array shown is M (columns) × N (rows), meaning the pixel array corresponding to the pixel circuit is M × N, and its corresponding column-level circuit is an M-column circuit. Both the sampling unit and the quantization unit are located at the column level, further reducing the area overhead at the pixel level, and the quantization implementation is not constrained by the pixel size.

[0020] Each sampling unit in the multiple sampling units is connected one-to-one with each row of a wide row in the pixel array. A wide row is composed of one or more rows in the pixel array. For example Figure 1 The wide row 1 shown consists of rows 1 through N / n, where n represents the number of wide rows. Assuming the pixel array is 256 columns × 256 rows, and the number of wide rows is 16, then each wide row consists of 16 rows: rows 1 through 16 form wide row 1, rows 17 through 32 form wide row 2, and so on, from row 240 to 256 form wide row n. Of course, it's understandable that if the number of rows is small, such as only 4 rows, then the wide row is equal to each row, resulting in a total of 4 wide rows. The number of wide rows is determined by those skilled in the art based on actual needs.

[0021] In a column-level circuit, each column corresponds to one quantization unit and multiple sampling units, and the number of sampling units in each column is (e.g., ...). Figure 1 The "N / n sampling units" shown are the same as the number of rows in a wide row. That is, the number of sampling units corresponds to the number of rows in a wide row. For example, if a wide row consists of 16 rows, then each column has 16 sampling units. If a wide row consists of 1 row, then each column has 1 sampling unit. For each column, regardless of the number of sampling units, there is only 1 quantization unit. The total number of quantization units equals the total number of columns; for example, if there are 256 columns, there are 256 quantization units.

[0022] In one embodiment of this application, when there are T rows in a wide row, the wide row time is divided into T small time segments t. Each time segment t reads the pixel signal of one row in the wide row into the corresponding sampling unit. After T time segments t, the pixel signals of all rows in the wide row are obtained, i.e., time-division readout. For example, if there are 4 rows in each wide row and the wide row time is 1 second, then the 1 second is divided into 4 time segments t, which is equivalent to each time segment t being 0.25 seconds. Every 0.25 seconds, the pixel signal of one row in the wide row is read into the corresponding sampling unit in the column-level circuit. After 4 time segments of 0.25 seconds, the pixel signals of all 4 rows in the wide row are obtained.

[0023] like Figure 2 The diagram shows the structure of column-level circuit 1 in one of the M columns, which includes quantization unit 1 and sampling unit 1, ..., sampling units N / n. The row width time = max(the sum of the sampling and readout times of N / n sampling units, and the quantization time of the quantization unit), where N represents the total number of rows in the pixel array, and n represents the number of wide rows. The row time of each wide row is equal to the sampling and readout time of the corresponding sampling unit in that row. Therefore, for each column, the quantization time of its quantization unit is equal to the sum of the sampling and readout times of all sampling units in that column.

[0024] During operation, in each wide row time interval, the pixel signal of each row corresponding to the wide row in a column is read out in time-division multiplexing into the sampling unit of that column, and then quantized using the quantization unit deployed in that column in the next quantization time interval.

[0025] After reading the pixel signals of all rows in the current wide row time, the quantization units in each column quantize the pixel signals of all rows read in the current wide row time in the next wide row time. The quantization time of the quantization unit is equal to the wide row time. For example... Figure 3 The diagram showing the relationship between quantization time TADC and sampling time TSH (i.e., sampling and readout time) in column 1 illustrates this. For each column's quantization unit and N / n sampling units, the sum of the sampling times TSH of multiple sampling units equals the row width time, which is also equal to the quantization time TADC of the quantization unit. For example, if there are 4 rows in a row and the row width time is 1 second, after reading the pixel signals of the 4 rows in the row within the current 1 second, the quantization units in each column will quantize the pixel signals of all rows in the row read in the current 1 second in the next 1 second. That is, while reading the pixel signals of the 4 rows in the row in the current 1 second, the quantization unit is quantizing the pixel signals that have already been read into the sampling units in the previous 1 second.

[0026] In one embodiment of this application, the sampling unit is a unit that reads out and stores pixel signals. It can be implemented in various ways, and a preferred implementation is described below. Figure 4 The schematic diagram of the multiple sampling units shown indicates that each sampling unit includes a readout subunit and a storage subunit.

[0027] The input terminal of the read sub-cell is connected to one row in the wide row, such as... Figure 4 The input terminal of read subunit 1 is connected to the first row of the wide row, and the input terminal of read subunit N / n is connected to the N / nth row of the wide row. The output terminal of the read subunit is connected to the input terminal of the storage subunit, as shown below. Figure 4The output terminal of the read subunit 1 is connected to the input terminal of the storage subunit 1, and the output terminal of the read subunit N / n is connected to the input terminal of the storage subunit N / n.

[0028] The readout subunit is used to sample and read out the pixel signal of the corresponding row; the output of the storage subunit is connected to the input of the target quantization unit, which is the quantization unit arranged in the column where the storage subunit is located. There are various ways to implement the readout subunit, such as using sensors to sample and read out pixel signals. One preferred implementation is that the readout subunit includes at least one sampling capacitor.

[0029] A quantization unit is a unit that quantizes the pixel signal. Since a quantization unit may be connected to multiple sampling units (in the case of a wide row consisting of multiple rows), the quantization unit not only needs to quantize but also needs to perform conversion. This is because the sampling units are essentially connected in parallel, and the quantization unit also needs to implement parallel-to-serial conversion. A preferred implementation method is described below. Figure 5 The schematic diagram of a quantization unit is shown. Each quantization unit includes at least one quantization subunit and one conversion subunit.

[0030] The number of quantization sub-units is the same as the number of sampling units deployed in its column. The input terminal of each quantization sub-unit is connected one-to-one with the output terminal of each sampling unit deployed in its column, such as... Figure 5 In the case of multiple quantization sub-units: the input of quantization sub-unit 1 is connected to the output of sampling unit 1, and the input of quantization sub-unit N / n is connected to the output of sampling unit N / n. Each quantization sub-unit is used to quantize its respective received pixel signal.

[0031] The outputs of all quantization subunits are connected to the conversion subunit, such as... Figure 5 The output terminals of quantization subunits 1 through N / n are all connected to the conversion subunit; the conversion subunit is used to convert the quantization results of all quantization subunits to obtain the quantization result corresponding to the column.

[0032] As can be seen from the above explanation and description, the readout circuit of the time-division readout quantization of this application reads out the pixel signal of each row corresponding to the wide row into the sampling unit of that column in a time-division manner during each wide row time. In the next quantization time, the quantization unit quantizes the pixel signal, which greatly extends the quantization time of each row and greatly alleviates the limitation of quantization time.

[0033] Based on the above-described time-division quantization readout circuit, this application also proposes an analog-to-digital converter, which includes: the time-division quantization readout circuit as described in any of the preceding claims.

[0034] Based on the above-described time-division quantization readout circuit, this application also proposes an electronic device, which includes: the time-division quantization readout circuit as described in any of the preceding claims.

[0035] In summary, the time-division multiplexing quantization readout circuit of this application includes: multiple sampling units and multiple quantization units arranged in the column-level circuit. Each sampling unit is connected one-to-one with each row of a wide row in the pixel array, where a wide row consists of one or more rows in the pixel array.

[0036] In the column-level circuit, each column corresponds to one quantization unit and multiple sampling units. The number of sampling units in each column is the same as the number of rows in the wide row. Specifically, during each wide row time interval, the pixel signal of each row corresponding to the wide row in a column is read out in a time-division multiplexing manner into the sampling unit of that column, and then quantized using the quantization unit deployed in that column during the next quantization time interval.

[0037] This application creatively proposes a time-division multiplexing quantization readout circuit, which differs from the traditional method of sequentially quantizing each row and then outputting data row by row during analog-to-digital conversion in large-scale pixel arrays. Instead, it divides the pixel array into multiple wide rows, and within each wide row's time interval, reads the pixel signal of each row into the sampling unit of that column in a time-division multiplexing manner. Since the transfer time of analog voltage is much shorter than the quantization time of the analog-to-digital converter, multiple analog voltages are serially transferred, and then the analog-to-digital converter can convert them in parallel. This greatly extends the quantization time of each row, effectively alleviating the limitation of quantization time. This achieves the goal of high-speed and accurate readout of infrared detectors, especially short- and mid-wave detectors, with low power consumption, and has broad application prospects and high practicality.

[0038] Although preferred embodiments of the present application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present application.

[0039] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0040] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims. All of these forms are within the protection scope of this application.

Claims

1. A readout circuit for time-division quantization, characterized in that, include: Multiple sampling units and multiple quantization units are deployed in the column-level circuit; Each sampling unit in the multiple sampling units is connected one-to-one with each row of the wide row in the pixel array, where the wide row is composed of one or more rows in the pixel array; In the column-level circuit, each column corresponds to one quantization unit and multiple sampling units, and the number of sampling units in each column is the same as the number of rows in the wide row. In each wide row time interval, the pixel signal of each row corresponding to the wide row in a column is read out in time-division multiplexing into the sampling unit of that column, and then quantized using the quantization unit deployed in that column in the next quantization time interval.

2. The readout circuit according to claim 1, characterized in that, When there are T rows in the wide row, the wide row time is divided into T small time segments t. In each small time segment t, the pixel signal of one row in the wide row is read into the sampling unit corresponding to that row. After T small time segments t, the pixel signals of all rows in the wide row are obtained.

3. The readout circuit according to claim 1, characterized in that, After reading the pixel signals of all rows in the current wide row time, the quantization unit deployed in each column quantizes the pixel signals of all rows in the current wide row time in the next wide row time. The quantization time of the quantization unit is equal to the wide row time.

4. The readout circuit according to claim 1, characterized in that, Each of the sampling units includes: a readout subunit and a storage subunit; The input terminal of the readout subunit is connected to one row of the wide row, and the output terminal is connected to the input terminal of the storage subunit. The readout subunit is used to sample and read out the pixel signal of the corresponding row. The output terminal of the storage sub-unit is connected to the input terminal of the target quantization unit, which is the quantization unit deployed in the column where the storage sub-unit is located.

5. The readout circuit according to claim 4, characterized in that, The readout subunit includes at least one sampling capacitor.

6. The readout circuit according to claim 1, characterized in that, Each quantization unit includes: at least one quantization subunit and one conversion subunit; The number of quantization sub-units is the same as the number of sampling units deployed in the same column. The input terminal of each quantization sub-unit is connected to the output terminal of each sampling unit deployed in the same column in a one-to-one correspondence. Each quantization sub-unit is used to quantize the pixel signal it receives. The output of all quantization subunits is connected to the conversion subunit, which is used to convert the quantization results of all quantization subunits to obtain the quantization result corresponding to the column.

7. The readout circuit according to claim 1, characterized in that, The wide row time = max(the sum of the sampling and readout times of N / n sampling units, and the quantization time of the quantization unit), where N represents the total number of rows in the pixel array, and n represents the number of wide rows.

8. The readout circuit according to claim 1, characterized in that, The row time of each row in the wide row is equal to the sampling and readout time of the corresponding sampling unit in that row.

9. An analog-to-digital converter, characterized in that, The analog-to-digital converter includes a readout circuit with time-division readout quantization as described in any one of claims 1-8.

10. An electronic device, characterized in that, The electronic device includes: a readout circuit with time-division readout quantization as described in any one of claims 1-8.

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