Avalanche diode laser probe power supply circuit

Abstract

The utility model discloses an avalanche diode laser probe power supply circuit relates to photoelectric probe measurement technical field. The circuit includes: field programmable gate array, switch circuit, wherein, the first input of switch circuit is connected with the first output of field programmable gate array, power supply circuit, wherein, the first input and the second input of power supply circuit are connected with the second output of field programmable gate array and the output of switch circuit respectively, to under the control of the adjustable voltage control signal provided by switch circuit and the start signal provided by field programmable gate array, provide working voltage to avalanche diode laser probe. The utility model solves the problem of high cost and the lack of system slice correction of high voltage power supply circuit of APD laser probe.

Description

Technical Field

[0001] This utility model relates to the field of photoelectric detector technology, specifically to a power supply circuit for an avalanche diode laser detector. Background Technology

[0002] APD (Avalanche Photodiode) laser detectors are characterized by low power consumption, small size, low noise, and low power supply voltage. Due to the avalanche characteristics of APD detectors, they are particularly sensitive to operating temperature. As temperature increases, the breakdown voltage increases; as temperature decreases, the breakdown voltage decreases. The stability of the detector output plays a crucial role in the accuracy of the entire system. If the ambient temperature changes during operation, the breakdown voltage will also change, causing fluctuations in the device's output gain and affecting its gain stability.

[0003] If the supply voltage of an APD laser detector is not adjusted according to the operating environment temperature, it is easily damaged by breakdown. To meet the system's required dynamic gain range and dynamic gain adjustment, a suitable supply voltage must be provided to the APD laser detector during operation. Therefore, closed-loop control of the APD laser detector is necessary during operation. Typically, designs only implement closed-loop control of the supply voltage and operating environment temperature, but this lacks system-level calibration, making it impossible to determine the correctness of the supply voltage output. Furthermore, the supply voltage of APD laser detectors is mostly provided by custom high-voltage power supply modules, which are costly. Summary of the Invention

[0004] This invention addresses the problems of high cost and lack of system-on-chip calibration in current high-voltage power supply circuits by providing a power supply circuit for avalanche diode laser detectors, thus solving the problems of high cost and lack of system-on-chip calibration in high-voltage power supply circuits for APD laser detectors.

[0005] This utility model is achieved through the following technical solution.

[0006] This invention provides a power supply circuit for an avalanche diode laser detector. The circuit includes: a field-programmable gate array (FPGA); a switching circuit, wherein a first input terminal of the switching circuit is connected to a first output terminal of the FPGA; and a power supply circuit, wherein a first input terminal and a second input terminal of the power supply circuit are respectively connected to a second output terminal of the FPGA and an output terminal of the switching circuit, so as to provide an operating voltage to the avalanche diode laser detector under the control of an adjustable voltage control signal provided by the switching circuit and a start signal provided by the FPGA.

[0007] In some embodiments, the circuit further includes a buffer, wherein the buffer is located between the field-programmable gate array and the power supply circuit, and is connected to a first output terminal of the field-programmable gate array and a first input terminal of the power supply circuit, respectively.

[0008] In some embodiments, the circuit further includes a temperature control circuit, wherein the temperature control circuit is connected to the input terminal of the field-programmable gate array (FPGA) to provide a temperature signal to the FPGA.

[0009] In some embodiments, the temperature control circuit includes: a sampling sub-circuit, configured to acquire the voltage value of a temperature sensor disposed in the avalanche diode laser detector, convert the voltage value into a resistance value, convert the resistance value into a temperature signal based on a lookup table, and send the temperature signal to the field-programmable gate array (FPGA) for processing into a conditioning switch control signal by the FPGA.

[0010] In some embodiments, the circuit further includes a conditioning circuit, wherein the conditioning circuit is connected to the output terminal of the power supply circuit and the second input terminal of the switching circuit, respectively.

[0011] In some embodiments, the conditioning circuit is a current acquisition circuit, used to sample the output voltage of the power supply circuit and convert it into a conditioning signal.

[0012] In some embodiments, the switching circuit includes a logic control module, wherein the logic control module is configured to control the output terminal of the switching circuit to output different adjustable voltage control signals based on different combinations of the conditioning signal output by the conditioning circuit and the conditioning switch control signal provided by the field programmable gate array.

[0013] In some embodiments, the output terminal of the power supply circuit is connected to an N-type field-effect transistor to provide operating voltage to the avalanche diode laser detector through the N-type field-effect transistor.

[0014] In some embodiments, the switching circuit uses a TS5A3359 chip.

[0015] In some embodiments, the power supply circuit uses the MAX1932 chip.

[0016] Compared with the prior art, this utility model has the following advantages and beneficial effects: by providing a high-precision high-voltage power supply circuit for the APD laser detector, it solves the problems of high cost and lack of system chip calibration in current high-voltage power supply circuits. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the exemplary embodiments of this utility model, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this utility model and therefore should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without any creative effort.

[0018] Figure 1 This is a schematic diagram of a power supply circuit for an avalanche diode laser detector according to an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of a power supply circuit for an avalanche diode laser detector according to an embodiment of the present invention.

[0020] Figure 3 This is a circuit diagram of a buffer according to an embodiment of the present invention.

[0021] Figure 4 This is a schematic diagram of a switching circuit according to an embodiment of the present invention.

[0022] Figure 5 This is a circuit diagram of a power supply circuit according to an embodiment of the present invention.

[0023] Figure 6 This is a circuit diagram of a power supply circuit for an avalanche diode laser detector according to an embodiment of the present invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this utility model are only for explaining this utility model and are not intended to limit this utility model.

[0025] This invention provides a high-voltage power supply circuit for a high-precision APD laser detector, providing bias voltage for the avalanche diode. An 8-bit SPI (Serial Peripheral Interface) of an FPGA (Field Programmable Gate Array) controls the DACOUT of a MAX1932, outputting a high-precision voltage of 1.3V~90V in 0.1V steps, with a precision of 5%. A TS5A3359 analog switch is used to control the feedback through three different combinations of resistor networks. The MAX1932, based on a PWM (Pulse Width Modulation) architecture, drives an N-type field-effect transistor, outputting high voltage to drive the APD laser detector. A temperature control circuit collects the temperature of the APD laser detector and transmits it to the FPGA via a UART (Universal Asynchronous Receiver / Transmitter). The FPGA controls the voltage of the APD laser detector based on the temperature, forming a closed-loop circuit.

[0026] Figure 1 This is a schematic diagram of a power supply circuit for an avalanche diode laser detector according to an embodiment of the present invention. (Reference) Figure 1 The power supply circuit for the avalanche diode laser detector includes: a field-programmable gate array, a switching circuit, and a power supply circuit.

[0027] Field-programmable gate arrays (FPGAs) are used to provide start signals to power supply circuits.

[0028] A switching circuit, whose first input terminal is connected to the first output terminal of a field-programmable gate array (FPGA), is used to receive signals provided by the FPGA, such as temperature signals.

[0029] The power supply circuit has its first and second input terminals connected to the second output terminal of the field-programmable gate array and the output terminal of the switching circuit, respectively, so as to provide the operating voltage to the avalanche diode laser detector under the control of the adjustable voltage control signal provided by the switching circuit and the start signal provided by the field-programmable gate array.

[0030] In this invention, the power supply circuit can be calibrated at the system level using an adjustable voltage control signal provided by the switching circuit, thereby providing operating voltage to the avalanche diode laser detector under the control of the start signal provided by the field-programmable gate array. This invention is illustrated using the TS5A3359 chip to implement the switching circuit and the MAX1932 chip to implement the power supply circuit as examples.

[0031] Figure 2This is a schematic diagram of a power supply circuit for an avalanche diode laser detector according to an embodiment of the present invention. The following references... Figure 2 Another power supply circuit for an avalanche diode laser detector according to this utility model will be described.

[0032] In some embodiments, reference Figure 2 The power supply circuit for this avalanche diode laser detector also includes a buffer, which is located between the field-programmable gate array (FPGA) and the power supply circuit, and is connected to the first output terminal of the FPGA and the first input terminal of the power supply circuit, respectively. Circuit buffers are key components in electronic circuits used for signal isolation, driving, or protection, and their main functions include voltage / current amplification, impedance matching, noise suppression, and prevention of signal reflection. In this invention, a CAVC4T245 is used to implement the buffer function.

[0033] Figure 3 This is a circuit diagram of a buffer (CAVC4T245) according to an embodiment of the present invention. A field-programmable gate array (FPGA) provides signals DAC_CLK, DAC_CS_N, and DAC_DIN to pins 4, 5, and 6 of the CAVC4T245, respectively. After processing by the CAVC4T245, signals 1932_SCLK, 1932_CS, and 1932_DIN are output to the power supply circuit through pins 13, 12, and 11 of the CAVC4T245, respectively.

[0034] In some embodiments, reference Figure 2 The power supply circuit for the avalanche diode laser detector also includes a temperature control circuit. This temperature control circuit is connected to the input of the field-programmable gate array (FPGA) to provide a temperature signal to the FPGA.

[0035] In some embodiments, the temperature control circuit includes a sampling sub-circuit. This sampling sub-circuit is configured to acquire the voltage value of a temperature sensor located in an avalanche diode laser detector, convert the voltage value into a resistance value, convert the resistance value into a temperature signal based on a lookup table, and send the temperature signal to a field-programmable gate array (FPGA) for processing into a conditioning switch control signal.

[0036] In some embodiments, reference Figure 2 The power supply circuit for the avalanche diode laser detector also includes a conditioning circuit, which is connected to the output terminal of the power supply circuit and the second input terminal of the switching circuit, respectively.

[0037] In some embodiments, the conditioning circuit is a current sampling circuit, used to sample the output voltage of the power supply circuit and convert it into a conditioning signal.

[0038] In some embodiments, the switching circuit includes a logic control module for controlling the output of the switching circuit to output different adjustable voltage control signals based on different combinations of the conditioning signal output by the conditioning circuit and the conditioning switch control signal provided by the field programmable gate array.

[0039] refer to Figure 4 The conditioning signal output from the conditioning circuit and the conditioning switch control signal provided by the field-programmable gate array are input to IN1 and IN2 of the TS5A3359 chip, respectively, and then input to the logic control module. Based on the high and low levels of the conditioning signal and the conditioning switch control signal, the logic control module determines which of NO0, NO1, and NO2 the COM terminal is connected to. NO0, NO1, and NO2 correspond to different resistor networks that control the feedback, thereby controlling the output voltage range of the switching circuit.

[0040] Referring to Table 1 below, when IN2 is low and IN1 is low, the switching circuit is off; when IN2 is low and IN1 is high, the switching circuit outputs the reference voltage corresponding to NO0; when IN2 is high and IN1 is low, the switching circuit outputs the reference voltage corresponding to NO1; when IN2 is high and IN1 is high, the switching circuit outputs the reference voltage corresponding to NO2.

[0041] Table 1

[0042]

[0043] Figure 5 This is a circuit diagram of a power supply circuit (MAX1932) according to an embodiment of the present invention. (See reference...) Figure 5 The buffer will output 1932_SCLK, 1932_CS, and 1932_DIN to SCLK, CS, and DIN of MAX1932 respectively, and the output of the switching circuit is connected to FB (feedback).

[0044] In some embodiments, the output of the power supply circuit is connected to an N-type field-effect transistor to provide operating voltage to the avalanche diode laser detector through the N-type field-effect transistor.

[0045] Figure 6 This is a circuit diagram of a power supply circuit for an avalanche diode laser detector according to an embodiment of the present invention. The following references... Figure 6 The working principle of the power supply circuit of the avalanche diode laser detector of this utility model is explained.

[0046] An APD laser detector has a temperature sensor (e.g., a thermistor) installed inside or around it. A temperature control circuit acquires the resistance value of this sensor and converts it into a temperature value (temperature signal). The APD laser detector operates at a corresponding voltage at this temperature. The temperature control circuit also transmits this temperature value to the FPGA via the UART protocol.

[0047] On one hand, the FPGA receives the temperature signal from the APD laser detector, processes it into a conditioning switch control signal suitable for the TS5A3359, and sends it to the TS5A3359; on the other hand, the FPGA also sends DAC_CLK, DAC_CS_N, and DAC_DIN to the corresponding ports of the CAVC4T245 via the SPI protocol as start signals.

[0048] After processing DAC_CLK, DAC_CS_N, and DAC_DIN, CAVC4T245 outputs 1932_SCLK, 1932_CS, and 1932_DIN to the corresponding ports of MAX1932, respectively.

[0049] The conditioning circuit samples the current of the output voltage VH_APD of MAX1932 and converts the sampled current into a conditioning signal, which is then input to IN2 of TS5A3359.

[0050] The TS5A3359 receives the conditioning switch control signal provided by the FPGA and the conditioning signal provided by the conditioning circuit. Through logic judgment, it determines the adjustable voltage control signal to be output to the MAX1932.

[0051] Under the control of signals provided by the FPGA and TS5A3359, the MAX1932 outputs a voltage. This output voltage is a constant frequency PWM, which is used to control the N-type field-effect transistor. The N-type field-effect transistor outputs a high operating voltage for the APD laser detector.

[0052] The FPGA controls a TS5A3359 analog switch to select the required channel resistor and sends the corresponding signal to the FB pin of the MAX1932. The MAX1932 internally uses constant frequency pulse width modulation (PWM) to drive an N-type field-effect transistor, outputting a high voltage to power the APD laser detector. The FPGA's 8-bit SPI controls the MAX1932's DACOUT, outputting a high-precision 5% voltage in 0.1V steps, with an output voltage range of 1.3V~90V and an input voltage range of 2.5V~5.5V. Simultaneously, current is detected at the output voltage. After the APD laser detector starts operating, a temperature control circuit uses a thermistor to obtain the detector's temperature value. This temperature is then analyzed by an ADC (analog-to-digital converter) and sent to the FPGA via UART. The FPGA adjusts the APD laser detector's voltage based on the received temperature reading.

[0053] This invention eliminates the need for costly custom high-voltage power supply modules. It employs a closed-loop control method, avoids using inaccurate feedback networks such as digital potentiometers, and performs current detection on the output high voltage. This solves the problem of high cost in existing high-voltage power supply circuits and achieves self-correcting closed-loop control based on its own temperature detection.

[0054] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A power supply circuit for an avalanche diode laser detector, characterized in that, The circuit includes: Field-programmable gate arrays (FPGAs); A switching circuit, wherein the first input terminal of the switching circuit is connected to the first output terminal of the field-programmable gate array; A power supply circuit, wherein the first input terminal and the second input terminal of the power supply circuit are respectively connected to the second output terminal of the field-programmable gate array and the output terminal of the switching circuit, so as to provide operating voltage to the avalanche diode laser detector under the control of the adjustable voltage control signal provided by the switching circuit and the start signal provided by the field-programmable gate array.

2. The circuit according to claim 1, characterized in that, The circuit further includes a buffer, wherein the buffer is located between the field-programmable gate array and the power supply circuit, and is connected to the first output terminal of the field-programmable gate array and the first input terminal of the power supply circuit, respectively.

3. The circuit according to claim 2, characterized in that, The circuit further includes a temperature control circuit, wherein the temperature control circuit is connected to the input terminal of the field-programmable gate array (FPGA) to provide a temperature signal to the FPGA.

4. The circuit according to claim 3, characterized in that, The temperature control circuit includes: The sampling sub-circuit is used to acquire the voltage value of the temperature sensor installed in the avalanche diode laser detector, convert the voltage value into a resistance value, convert the resistance value into a temperature signal based on a lookup table, and send the temperature signal to the field programmable gate array (FPGA) for processing into a conditioning switch control signal.

5. The circuit according to any one of claims 1 to 4, characterized in that, The circuit further includes a conditioning circuit, wherein the conditioning circuit is connected to the output terminal of the power supply circuit and the second input terminal of the switching circuit, respectively.

6. The circuit according to claim 5, characterized in that, The conditioning circuit is a current acquisition circuit, which is used to sample the current of the output voltage of the power supply circuit and convert it into a conditioning signal.

7. The circuit according to claim 6, characterized in that, The switching circuit includes a logic control module, wherein the logic control module is used to control the output terminal of the switching circuit to output different adjustable voltage control signals based on different combinations of the conditioning signal output by the conditioning circuit and the conditioning switch control signal provided by the field programmable gate array.

8. The circuit according to claim 1, characterized in that, The output terminal of the power supply circuit is connected to an N-type field-effect transistor to provide operating voltage to the avalanche diode laser detector through the N-type field-effect transistor.

9. The circuit according to claim 1, characterized in that, The switching circuit uses the TS5A3359 chip.

10. The circuit according to claim 1, characterized in that, The power supply circuit uses the MAX1932 chip.

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