Temperature control device and method of semiconductor cooler and laser device

Abstract

The invention discloses a temperature control device and method of a semiconductor cooler and a laser device. The temperature control device of the semiconductor cooler comprises a semiconductor cooler driving circuit, a temperature control circuit and a temperature control circuit, wherein a driving signal output end of the semiconductor cooler driving circuit is connected with the semiconductor cooler; the output end of the temperature adjusting circuit is connected with the semiconductor cooler driving circuit, and the temperature adjusting circuit is used for sending an adjusting signal to the semiconductor cooler driving circuit according to the temperature of the semiconductor cooler. In this way, the laser temperature control effect can be improved.

Description

Technical Field

[0001] This application relates to the field of semiconductor refrigeration, and in particular to a temperature control device, method, and laser device for a semiconductor refrigeration unit. Background Technology

[0002] In laser applications, frequency doubling crystal temperature control typically employs dedicated TEC driver chip solutions, such as Maxim Integrated's MAX1978 series and Analog Devices' ADN8830 series. These solutions are relatively expensive, have specific voltage requirements for the TEC, and are generally designed for low-voltage, low-current TECs. They also exhibit inflexibility in terms of supply voltage and temperature setting, thus limiting their application. Some high-voltage TEC drivers utilize PWM signals to control a full-bridge circuit composed of MOS transistors to achieve TEC cooling and heating. However, the high-voltage switching signals from the MOS transistors increase radiation and ripple in this circuit, making it difficult to achieve high-precision temperature control using PID algorithms. Therefore, in high-power lasers, low-voltage, low-current TECs exhibit slow response times, while high-voltage TECs suffer from significant driver ripple. Summary of the Invention

[0003] This application mainly provides a temperature control device, method, and laser device for a semiconductor cooler to solve the problem of poor temperature control performance in lasers.

[0004] To solve the above-mentioned technical problems, one technical solution adopted in this application is: to provide a temperature control device for a semiconductor cooler, comprising: a semiconductor cooler driving circuit, wherein the driving signal output terminal of the semiconductor cooler driving circuit is connected to the semiconductor cooler; and a temperature regulating circuit, wherein the output terminal of the temperature regulating circuit is connected to the semiconductor cooler driving circuit, and is used to send an regulating signal to the semiconductor cooler driving circuit according to the temperature of the semiconductor cooler.

[0005] In some embodiments, the semiconductor cooler driving circuit includes a digital-to-analog converter unit, a voltage gain amplifier unit, and a current gain amplifier unit; the input terminal of the digital-to-analog converter unit is connected to the output terminal of the temperature regulation circuit, the output terminal of the digital-to-analog converter unit is connected to the input terminal of the voltage gain amplifier unit, the output terminal of the voltage gain amplifier unit is connected to the input terminal of the current gain amplifier unit, and the output terminal of the voltage gain amplifier unit is connected to the semiconductor cooler.

[0006] In some embodiments, the digital-to-analog converter includes a positive-to-negative voltage conversion chip, a first operational amplifier, and a first capacitor; a first terminal of the positive-to-negative voltage conversion chip is connected to a first signal input terminal, a second terminal of the positive-to-negative voltage conversion chip is connected to a first power supply positive terminal, a third terminal of the positive-to-negative voltage conversion chip is connected to both the first terminal of the first capacitor and the first terminal of the first operational amplifier, a fourth terminal of the positive-to-negative voltage conversion chip is connected to both the second terminal of the first operational amplifier and the second terminal of the first capacitor, a fifth terminal of the positive-to-negative voltage conversion chip is connected to the third terminal of the first operational amplifier, and a sixth terminal of the positive-to-negative voltage conversion chip is grounded; a fourth terminal of the first operational amplifier is connected to the first power supply positive terminal, a fifth terminal of the first operational amplifier is connected to the first power supply negative terminal, and a first terminal of the first operational amplifier serves as the output terminal of the digital-to-analog converter.

[0007] In some embodiments, the voltage gain amplification unit includes a second operational amplifier, a first resistor, and a second resistor; the first terminal of the second operational amplifier serves as the input terminal of the voltage gain amplification unit, the second terminal of the second operational amplifier is connected to both the first terminal of the first resistor and the first terminal of the second resistor, the third terminal of the second operational amplifier is connected to the second terminal of the second resistor and serves as the output terminal of the voltage gain amplification unit, the fourth terminal of the second operational amplifier is connected to the positive terminal of the second power supply, the fifth terminal of the second operational amplifier is connected to the negative terminal of the second power supply, and the second terminal of the first resistor is grounded.

[0008] In some embodiments, the current gain amplification unit includes a first transistor and a second transistor; the first end of the first transistor is connected to the first end of the second transistor and together serve as the input terminal of the current gain amplification unit; the second end of the first transistor is connected to the positive terminal of the second power supply; the third end of the first transistor is connected to the second end of the second transistor and together serve as the output terminal of the current gain amplification unit; and the third end of the second transistor is connected to the negative terminal of the second power supply.

[0009] In some embodiments, the temperature regulation circuit includes a processor, a thermistor, a third operational amplifier, a second capacitor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, and a seventh resistor; the first terminal of the third operational amplifier is simultaneously connected to the first terminal of the sixth resistor and the input terminal of the processor; the second terminal of the third operational amplifier is simultaneously connected to the first terminal of the thermistor, the first terminal of the second capacitor, the first terminal of the fourth resistor, and the first terminal of the third resistor; the third terminal of the third operational amplifier is simultaneously connected to the first terminal of the fifth resistor, the first terminal of the seventh resistor, and the second terminal of the sixth resistor; the fourth terminal of the third operational amplifier is connected to the positive terminal of a third power supply; the fifth terminal of the third operational amplifier is connected to the negative terminal of a third power supply; the second terminal of the thermistor, the second terminal of the second capacitor, and the second terminal of the fourth resistor are all grounded; the second terminal of the third resistor is simultaneously connected to the second terminal of the fifth resistor and the second signal input terminal; the second terminal of the seventh resistor is grounded; and the output terminal of the processor serves as the output terminal of the temperature regulation circuit.

[0010] To solve the above-mentioned technical problems, another technical solution adopted in this application is: to provide a temperature control method for a semiconductor cooler, used in the temperature control device described above, including: acquiring the current temperature value of the semiconductor cooler; calculating the temperature error between the current temperature value and the target temperature value; and when the temperature error is greater than a preset error threshold, generating a drive adjustment signal based on the temperature error to adjust the temperature of the semiconductor cooler.

[0011] In some embodiments, acquiring the current temperature value of the thermoelectric cooler includes: converting the temperature of the thermoelectric cooler into a temperature voltage signal using a thermistor; and quantizing the temperature voltage signal level into the current temperature value.

[0012] In some embodiments, generating a drive adjustment signal based on the temperature error includes: determining the direction of the voltage setpoint quantization value and the drive adjustment signal according to the sign of the temperature error; and outputting a drive adjustment signal in the corresponding direction according to the voltage setpoint quantization value.

[0013] In some embodiments, the formula for calculating the voltage given quantization value is as follows:

[0014] Among them, V n A quantized value, ΔE, is given for the voltage. n For temperature error, E is the cumulative temperature error, K p1 For temperature-voltage output proportional gain, K i1 This is the integral gain of the temperature-voltage output.

[0015] This application also provides a laser device, which includes a laser, a thermoelectric cooler, and a temperature control device as described above, wherein the thermoelectric cooler is used to regulate the operating temperature of the laser.

[0016] The beneficial effects of this application are as follows: Unlike existing technologies, this application discloses a temperature control device, method, and laser device for a semiconductor cooler. The drive signal output terminal of the semiconductor cooler drive circuit is connected to the semiconductor cooler. Through the generation, amplification, and power drive of analog voltage signals, precise control of the cooling or heating mode and power of the semiconductor cooler is achieved. Analog voltage control replaces traditional PWM switching control, avoiding ripple interference generated by the switching circuit, reducing system noise, and improving temperature control accuracy. It supports high-voltage or low-voltage semiconductor cooler power supply, is applicable to various specifications of semiconductor coolers, and directly drives the semiconductor cooler with analog signals, eliminating PWM modulation delay and improving the dynamic response speed of temperature regulation. The output terminal of the temperature regulation circuit is connected to the semiconductor cooler drive circuit and is used to send an adjustment signal to the semiconductor cooler drive circuit according to the temperature of the semiconductor cooler. Through temperature acquisition, signal quantization, and closed-loop feedback control, dynamic regulation of the semiconductor cooler is achieved. Real-time monitoring of temperature changes and adjustment of the drive signal adapts to the stringent requirements of dynamic temperature changes in scenarios such as laser frequency doubling crystals. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein: Figure 1 This is a schematic diagram of the structure of an embodiment of the temperature control device for a semiconductor cooler provided in this application; Figure 2 Is it like this? Figure 1 The diagram shows a schematic representation of an embodiment of the semiconductor cooler drive circuit of the device shown. Figure 3 Is it like this? Figure 2 The circuit diagram shown is a schematic diagram of an embodiment of the digital-to-analog converter unit of the device shown. Figure 4 Is it like this? Figure 2 The circuit diagram shown is a schematic diagram of an embodiment of the voltage gain amplification unit of the device shown. Figure 5 Is it like this? Figure 2 The circuit diagram shown is a schematic diagram of an embodiment of the current gain amplification unit of the device shown. Figure 6 Is it like this? Figure 1The circuit diagram shown is a schematic diagram of one embodiment of the temperature regulation circuit of the device shown. Figure 7 This is a schematic flowchart of an embodiment of the temperature control method for a semiconductor cooler provided in this application. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0019] The terms "first," "second," and "third" used in the embodiments of this application are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.

[0020] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0021] See Figure 1 , Figure 1 This is a schematic diagram of an embodiment of the temperature control device for a thermoelectric cooler (TEC) provided in this application. The temperature control device includes: a TEC drive circuit 100, whose drive signal output terminal is connected to the TEC; and a temperature adjustment circuit 200, whose output terminal is connected to the TEC drive circuit 100, for sending an adjustment signal to the TEC drive circuit 100 according to the temperature of the TEC.

[0022] The temperature control circuit 200 collects the temperature signal from the temperature control terminal of the thermoelectric cooler (TEC) in real time, processes it to generate an adjustment command, and the TEC drive circuit 100 converts the command into a drive voltage to control the cooling or heating state of the TEC, ultimately achieving high-precision and stable control of the target temperature.

[0023] The thermoelectric cooler (TEC) drive circuit 100 is responsible for converting the regulation signal into the drive signal required by the TEC. The temperature regulation circuit 200 is responsible for acquiring temperature and generating regulation signals, and includes a temperature acquisition module, an analog-to-digital converter module, and a temperature control unit.

[0024] The temperature regulation circuit 200 converts the temperature of the thermoelectric cooler (TEC) into a voltage signal via a thermistor NTC, and obtains a quantized temperature value after analog-to-digital conversion. The temperature regulation circuit 200 compares the current quantized temperature value with the target value, calculates the temperature error using a PID algorithm, and generates a corresponding regulation signal. The TEC drive circuit 100 receives the regulation signal, performs digital-to-analog conversion, voltage amplification, and current amplification, and outputs a drive signal to the TEC to control its cooling or heating. This process is repeated to achieve rapid temperature convergence and stabilization.

[0025] The thermoelectric cooler (TEC) is driven by analog signals, avoiding interference from switching circuit ripple. It supports both high and low voltage TEC power supplies, and its linear amplification design reduces electromagnetic radiation and power supply ripple, improving system immunity.

[0026] Further, see Figure 2 , Figure 2 Is it like this? Figure 1 The diagram illustrates a structural design of an embodiment of the thermoelectric cooler (TEC) drive circuit 100. The TEC drive circuit 100 includes a digital-to-analog converter (DAC) unit 110, a voltage gain amplifier unit 120, and a current gain amplifier unit 130. The input terminal of the DAC unit 110 is connected to the output terminal of the temperature regulation circuit 200. The output terminal of the DAC unit 110 is connected to the input terminal of the voltage gain amplifier unit 120. The output terminal of the voltage gain amplifier unit 120 is connected to the input terminal of the current gain amplifier unit. The output terminal of the voltage gain amplifier unit 120 is connected to the thermoelectric cooler (TEC).

[0027] The temperature regulation circuit 200 generates a regulation signal, which is converted into an analog voltage by the digital-to-analog converter 110. The voltage gain amplifier 120 amplifies the signal proportionally to the voltage range required by the thermoelectric cooler TEC. The current gain amplifier 130 then boosts the drive current, and finally the drive signal is output to the thermoelectric cooler TEC to achieve closed-loop temperature control.

[0028] The digital-to-analog converter 110 outputs a bipolar voltage, which, in conjunction with the linear amplification of the voltage gain amplifier 120, avoids interference from switching circuit ripple and achieves a control accuracy of ±0.01℃.

[0029] Further, see Figure 3 , Figure 3 Is it like this? Figure 2 The circuit diagram shown is a schematic diagram of an embodiment of the digital-to-analog converter unit 110. The digital-to-analog converter unit 110 includes a positive-to-negative voltage conversion chip IC1, a first operational amplifier IC2, and a first capacitor C1.

[0030] The first terminal of the positive-to-negative voltage converter chip IC1 is connected to the first signal input terminal VREF1. The second terminal of the positive-to-negative voltage converter chip IC1 is connected to the first positive power supply VCC1+. The third terminal of the positive-to-negative voltage converter chip IC1 is simultaneously connected to the first terminal of the first capacitor C1 and the first terminal of the first operational amplifier IC2. The fourth terminal of the positive-to-negative voltage converter chip IC1 is simultaneously connected to the second terminal of the first operational amplifier IC2 and the second terminal of the first capacitor C1. The fifth terminal of the positive-to-negative voltage converter chip IC1 is connected to the third terminal of the first operational amplifier IC2. The sixth terminal of the positive-to-negative voltage converter chip IC1 is grounded. The fourth terminal of the first operational amplifier IC2 is connected to the first positive power supply VCC1+. The fifth terminal of the first operational amplifier IC2 is connected to the first negative power supply VCC1-. The first terminal of the first operational amplifier IC2 serves as the output terminal of the digital-to-analog converter unit 110.

[0031] The positive and negative voltage conversion chip IC1 receives digital signals and generates bipolar analog voltages. After being buffered and filtered by the first operational amplifier IC2, stable positive and negative voltage signals are output, providing accurate voltage input for the subsequent voltage gain amplification unit 120.

[0032] The positive-to-negative voltage conversion chip IC1 converts the digital adjustment signal into a bipolar analog voltage. Its first terminal is connected to the first signal input terminal VREF1, receiving the digitally quantized signal output from the temperature control unit as the reference for voltage conversion. The second terminal is connected to the positive terminal VCC1+ of the first power supply, providing the chip's operating voltage. The third terminal outputs the initially converted bipolar voltage and is simultaneously connected to the first capacitor C1 and the positive input terminal of the first operational amplifier IC2, transmitting the original analog signal. The fourth terminal is connected to the output terminal of the first operational amplifier IC2 and the other end of the first capacitor C1, forming a closed-loop feedback path, which, together with the capacitor, achieves filtering. The fifth terminal is connected to the inverting input terminal of the first operational amplifier IC2, providing a reference voltage to ensure conversion accuracy. The sixth terminal is the chip's ground terminal, stabilizing the circuit's reference potential.

[0033] The first operational amplifier IC2 is used for buffering, filtering, and voltage following. Its first terminal serves as the total output terminal of the digital-to-analog converter unit 110, outputting a stable bipolar voltage U0 to the voltage gain amplifier unit 120. Its second terminal is connected to the fourth terminal of the positive-to-negative voltage conversion chip IC1 and the other end of the first capacitor C1, receiving feedback signals and forming a virtual short with the positive input voltage to constitute a voltage follower. Its third terminal receives the original analog voltage output from the third terminal of the positive-to-negative voltage conversion chip IC1 as the input signal. Its fourth and fifth terminals are connected to the positive terminal VCC1+ and the negative terminal VCC1- of the first power supply, respectively, to provide operating voltage and ensure that the amplifier operates linearly within the bipolar voltage range.

[0034] The first capacitor C1 is used for filtering and ripple suppression. It is connected in parallel between the third and fourth terminals of the positive and negative voltage conversion chip IC1. Together with the first operational amplifier IC2, it forms an RC low-pass filter circuit to filter out high-frequency noise and ripple generated during digital signal conversion, smooth the voltage output, and improve signal stability.

[0035] The positive and negative voltage conversion chip IC1 receives a digital adjustment signal from the temperature regulation circuit 200 through its first terminal; based on the positive and negative power supply of the first power supply, the chip internally converts the digital signal into a bipolar analog voltage in the range of -VREF / 2 to +VREF / 2; the first capacitor C1 and the first operational amplifier IC2 form a low-pass filter circuit to smooth the chip's output voltage and reduce ripple interference; the first operational amplifier IC2 operates in voltage follower mode, with low output impedance and strong load-carrying capacity, ensuring that the voltage signal is stably transmitted to subsequent units.

[0036] The positive-to-negative voltage conversion chip IC1 generates a precise bipolar voltage ranging from -VREF / 2 to +VREF / 2. Combined with the low offset voltage characteristics of the first operational amplifier IC2, this ensures low voltage conversion error. The filter circuit formed by the first capacitor C1 and the operational amplifier suppresses ripple voltage, preventing high-frequency noise interference to subsequent amplification units and meeting the high-precision temperature control requirements of the thermoelectric cooler (TEC). The voltage follower design results in low output impedance and a response speed in the μs range, adaptable to voltage gain amplifier units 120 with different bandwidths, and compatible with both high and low voltage TEC drive scenarios. A dynamic adjustment mechanism is formed through the feedback connection between the fourth terminal and the operational amplifier output. When the input signal fluctuates, the output voltage deviation can converge within 10μs, ensuring precise execution of the temperature control unit's adjustment signal.

[0037] Further, see Figure 4 , Figure 4 Is it like this? Figure 2 The circuit diagram shows an embodiment of the voltage gain amplifier unit 120. The voltage gain amplifier unit 120 includes a second operational amplifier IC3, a first resistor R1, and a second resistor R2.

[0038] The first terminal of the second operational amplifier IC3 serves as the input terminal of the voltage gain amplification unit 120. The second terminal of the second operational amplifier IC3 is connected to both the first terminal of the first resistor R1 and the first terminal of the second resistor R2. The third terminal of the second operational amplifier IC3 is connected to the second terminal of the second resistor R2 and serves as the output terminal of the voltage gain amplification unit 120. The fourth terminal of the second operational amplifier IC3 is connected to the positive terminal of the second power supply VCC2+. The fifth terminal of the second operational amplifier IC3 is connected to the negative terminal of the second power supply VCC2-. The second terminal of the first resistor R1 is grounded.

[0039] The second operational amplifier IC3, the first resistor R1, and the second resistor R2 form a non-inverting amplifier circuit, which amplifies the small-range voltage signal received at the input terminal to the positive and negative supply voltage range by a fixed ratio, providing a wide voltage drive signal for the subsequent current gain amplifier unit 130.

[0040] The second operational amplifier IC3 is used to amplify the voltage signal proportionally, providing bipolar output capability. Its first terminal receives the original voltage signal U0 output from the digital-to-analog converter 110, serving as the input to the amplifier circuit. Its second terminal is simultaneously connected to the first terminals of the first resistor R1 and the second resistor R2, stabilizing the amplification factor through a negative feedback network. Its third terminal outputs the amplified voltage signal U1, serving as the total output of the voltage gain amplifier unit 120. Its fourth and fifth terminals are respectively connected to the positive terminal VCC2+ and the negative terminal VCC2- of the second power supply, providing positive and negative operating voltages to ensure linear operation of the amplifier within the bipolar voltage range.

[0041] The first terminal of the second operational amplifier IC3 receives the voltage signal output by the digital-to-analog converter unit 110; through the feedback network formed by the first resistor R1 and the second resistor R2, the input voltage is amplified proportionally, and the amplification factor is determined by the resistor ratio; based on the positive and negative terminals of the second power supply, the output voltage range is from the negative terminal VCC2- of the second power supply to the positive terminal VCC2+ of the second power supply, which meets the high and low voltage drive requirements of the semiconductor cooler TEC.

[0042] By designing the ratio of the first resistor R1 and the second resistor R2, the small range of voltage output by the digital-to-analog converter unit 110 can be controlled. The linear amplification characteristic of the second operational amplifier IC3, combined with the negative feedback network, ensures that the output voltage and the input voltage have a strictly linear relationship. Based on the positive and negative power supply of the second power supply, the output voltage can be continuously adjusted within the positive and negative range. The non-inverting amplifier circuit has high input impedance and low output impedance, reducing signal transmission loss. The grounding design of the first resistor R1 suppresses common-mode interference. Combined with the low noise characteristic of the second operational amplifier IC3, the output ripple voltage is ≤5mV, improving the system's anti-interference capability.

[0043] See Figure 5 , Figure 5Is it like this? Figure 2 The circuit diagram shown is a schematic diagram of an embodiment of the current gain amplifier unit 130. The current gain amplifier unit 130 includes a first transistor Q1 and a second transistor Q2.

[0044] The first terminal of the first transistor Q1 is connected to the first terminal of the second transistor Q2, and together they serve as the input terminal of the current gain amplification unit 130. The second terminal of the first transistor Q1 is connected to the positive terminal of the second power supply VCC2+. The third terminal of the first transistor Q1 is connected to the second terminal of the second transistor Q2, and together they serve as the output terminal of the current gain amplification unit 130. The third terminal of the second transistor Q2 is connected to the negative terminal of the second power supply VCC2-.

[0045] A push-pull circuit is formed by the first transistor Q1 (NPN type) and the second transistor Q2 (PNP type) to convert the voltage signal output by the voltage gain amplifier unit 120 into a high current drive signal, thereby realizing bidirectional current control of the semiconductor cooler TEC.

[0046] In this design, the first transistor Q1 is used to provide the forward drive current. Its first terminal is the base, which is connected to the base of the second transistor Q2 and receives the voltage signal U1 output by the voltage gain amplifier unit 120 to control the transistor's conduction state. Its second terminal is the collector, which is connected to the positive terminal VCC2+ of the second power supply and serves as the power supply terminal for the forward current. Its third terminal is the emitter, which is connected to the emitter of the second transistor Q2 and together they serve as the output terminal of the current gain amplifier unit 130 to output the forward current to the thermoelectric cooler TEC.

[0047] The second transistor Q2 is used to provide reverse drive current. The first terminal is the base, which is connected to the base of the first transistor Q1 and receives the voltage signal U1 to control the conduction state of the transistor; the second terminal is the emitter, which is connected to the emitter of the first transistor Q1 and together they serve as the output terminal to output reverse current to the thermoelectric cooler TEC; the third terminal is the collector, which is connected to the negative terminal of the second power supply VCC2- and serves as the power supply terminal for the reverse current.

[0048] Optionally, the first transistor Q1 is an NPN transistor, and the second transistor Q2 is a PNP transistor. When U1>0, the base voltage is higher than the emitter voltage, the NPN transistor conducts, and the current flows from the collector to the emitter, then through the output terminal into the thermoelectric cooler (TEC) to achieve heating. When U1<0, the base voltage is lower than the emitter voltage, the PNP transistor conducts, and the current flows from the emitter through the output terminal into the TEC, then back through the collector to achieve cooling.

[0049] The first terminals of transistors Q1 and Q2 jointly receive the voltage signal U1 output by the voltage gain amplifier unit 120. When the input voltage U1 is positive, transistor Q1 is turned on, outputting a positive current from the positive terminal VCC2+ of the second power supply to the TEC, causing the thermoelectric cooler TEC to enter the heating mode; when the input voltage U1 is negative, transistor Q2 is turned on, outputting a reverse current from the negative terminal VCC2- of the second power supply to the thermoelectric cooler TEC, causing the thermoelectric cooler TEC to enter the cooling mode; the third terminal of transistor Q1 and the second terminal of transistor Q2 are connected in parallel as the output terminal, providing a continuously adjustable drive current to the thermoelectric cooler TEC. The direction of the current is determined by the polarity of the input voltage, and the magnitude is limited by the maximum allowable current of the transistors.

[0050] Specifically, the output voltage U1 of the second operational amplifier IC3 can be controlled by... Calculated.

[0051] The push-pull circuit converts the small current signal from the voltage gain amplifier unit 120 into a large current output by alternating the conduction of NPN and PNP transistors, overcoming the power limitations of low-voltage, low-current TEC driver chips and adapting to high-voltage, high-current TEC scenarios. Seamless switching between heating and cooling modes is achieved based on the input voltage polarity: when voltage U1>0, a forward current is output for heating; when U1<0, a reverse current is output for cooling, meeting the bidirectional temperature regulation requirements of TECs.

[0052] See Figure 6 , Figure 6 Is it like this? Figure 1 The circuit diagram shows an embodiment of the temperature regulation circuit 200 of the device shown. The temperature regulation circuit 200 includes a processor IC5, a thermistor NTC, a third operational amplifier IC4, a second capacitor C2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and a seventh resistor R7.

[0053] The first terminal of the third operational amplifier IC4 is simultaneously connected to the first terminal of the sixth resistor R6 and the input terminal of the processor IC5. The second terminal of the third operational amplifier IC4 is simultaneously connected to the first terminal of the thermistor NTC, the first terminal of the second capacitor C2, the first terminal of the fourth resistor R4, and the first terminal of the third resistor R3. The third terminal of the third operational amplifier IC4 is simultaneously connected to the first terminal of the fifth resistor R5, the first terminal of the seventh resistor R7, and the second terminal of the sixth resistor R6. The fourth terminal of the third operational amplifier IC4 is connected to the positive terminal of the third power supply VCC3+, and the fifth terminal of the third operational amplifier IC4 is connected to the negative terminal of the third power supply VCC3-.

[0054] The second terminal of the thermistor NTC, the second terminal of the second terminal of the second terminal of the second terminal of the fourth resistor R4 are grounded together. The second terminal of the third resistor R3 is connected to the second terminal of the fifth resistor R5 and the second signal input terminal VREF2. The second terminal of the seventh resistor R7 is grounded. The output terminal of the processor IC5 serves as the output terminal of the temperature regulation circuit 200.

[0055] Specifically, the voltage at the positive input terminal of the third operational amplifier IC4 is .

[0056] Where Rntc||R4 represents the resistance value of the thermistor NTC connected in parallel with R4.

[0057] The circuit diagram shows that the ideal gain is achieved by connecting R5 and R7 in parallel. Let R5||R7 represent the resistance of R5 and R7 in parallel. From the circuit diagram, the ideal output can be calculated as follows: .

[0058] Considering the presence of gain and bias voltage, the actual output voltage of the third operational amplifier IC4 can be calculated from the schematic diagram as follows: .

[0059] Temperature changes are sensed by a thermistor NTC, and the temperature signal is linearized and converted into a voltage signal by an amplification and filtering circuit composed of the third operational amplifier IC4. After being input into the processor IC5, the voltage signal is compared with the target temperature, and the adjustment signal is output through a PID algorithm to realize closed-loop temperature control of the thermoelectric cooler TEC.

[0060] Optionally, the thermistor NTC is a negative temperature coefficient thermistor, whose resistance decreases as temperature increases and increases as temperature decreases. As a temperature-sensitive element, the resistance of the thermistor NTC changes with the temperature of the thermoelectric cooler (TEC). The temperature change is converted into a voltage change through a voltage divider network, providing the raw signal for subsequent amplification.

[0061] The third operational amplifier IC4 is used to form a differential amplifier circuit to achieve linear amplification and noise suppression of the temperature signal.

[0062] A resistor network consisting of the third resistor R3, the fourth resistor R4, the fifth resistor R5, the sixth resistor R6, and the seventh resistor R7 forms a voltage divider circuit, which converts the resistance change of the thermistor NTC into a voltage change.

[0063] The second capacitor C2 is connected in parallel across the thermistor NTC as a low-pass filter capacitor to filter out high-frequency noise in the voltage divider signal of the thermistor NTC, smooth voltage fluctuations, and avoid interfering with the analog-to-digital conversion accuracy of the processor IC5.

[0064] The processor IC5 is used to implement temperature closed-loop control algorithms such as PID regulation. It receives the temperature voltage signal output by the third operational amplifier IC4 through its input terminal, quantizes the analog signal into a digital quantity through the built-in analog-to-digital converter, compares the current quantized temperature value with the target value, calculates the error, generates a voltage regulation signal through the PID algorithm, and sends the voltage regulation signal to the digital-to-analog converter unit 110 as the output terminal of the temperature regulation circuit 200 to control the heating / cooling state.

[0065] The thermistor changes its resistance with temperature, converting the temperature signal into a resistance change. The third operational amplifier IC4, together with external resistors and capacitors, forms a differential amplifier and filter circuit to convert the resistance change into a linear voltage signal. The processor IC5 receives the amplified voltage signal, compares it with the target temperature quantization value, and calculates the temperature error. Based on the error value, a voltage regulation signal is generated through a PID algorithm and output to the digital-to-analog converter unit 110 to control the thermoelectric cooler TEC to heat or cool.

[0066] The voltage divider network formed by the thermistor NTC and the fourth resistor R4, combined with the differential amplification of the third operational amplifier IC4, achieves linearization of the temperature signal. The filtering effect of the second capacitor C2 and the common-mode rejection ratio of the third operational amplifier IC4 effectively suppress environmental electromagnetic interference and power supply ripple. Through the real-time error feedback of the processor IC5 and the dynamic adjustment of PID parameters, the temperature fluctuation under constant temperature environment is ≤±0.02℃, solving the problem of low accuracy in traditional open-loop control.

[0067] See Figure 7 , Figure 7 This is a schematic flowchart of an embodiment of the temperature control method for a thermoelectric cooler (TEC) provided in this application. The temperature control method for the TEC includes the following steps: 10: Collect the current temperature value of the thermoelectric cooler (TEC).

[0068] The thermistor (NTC) is in contact with the thermoelectric cooler (TEC), and its resistance changes with the current temperature of the TEC, converting the temperature signal into a resistance change. Through the high sensitivity of the thermistor (NTC) and a linear amplification circuit, a linear conversion of the temperature-to-voltage signal is achieved.

[0069] Furthermore, step 1 also includes the following steps: 11: The temperature of the thermoelectric cooler (TEC) is converted into a temperature voltage signal through a thermistor (NTC).

[0070] The thermistor NTC is in contact with the thermoelectric cooler TEC. Its resistance changes with the current temperature of the TEC, converting the temperature signal into a resistance change. The thermistor NTC is connected in series with the fourth resistor R4 and grounded. The third resistor R3 is connected to the second signal input terminal VREF2, and the three form a voltage divider circuit. The change in the resistance of the thermistor NTC causes a change in the voltage across it, forming the original temperature voltage signal. The second capacitor C2 is connected in parallel across the thermistor NTC to filter out high-frequency noise. The third operational amplifier IC4 and the resistor network form a differential amplifier circuit, linearly amplifying the divided voltage into a temperature voltage signal proportional to the temperature.

[0071] 12: Quantize the temperature voltage signal level into the current temperature value.

[0072] The temperature voltage signal U4 is input to the analog-to-digital converter module and converted into a digital quantity. This quantized value has a linear relationship with the temperature. The quantized value is then transmitted to the temperature control unit as a digital representation of the current temperature, used to compare it with the target temperature and calculate the adjustment error.

[0073] By utilizing the high sensitivity of the thermistor NTC and a linear amplification circuit, precise conversion between temperature and voltage signals is achieved, providing a reliable analog signal for subsequent quantization.

[0074] 20: Calculate the temperature error between the current temperature value and the target temperature value.

[0075] The temperature acquisition module converts the current temperature of the thermoelectric cooler (TEC) into a temperature-voltage signal, which is then converted into a quantized value En0 of the current temperature by the analog-to-digital converter. The processor IC5 of the temperature control unit presets the target quantized value En, which serves as the reference value for temperature control.

[0076] The temperature control unit calculates the difference between the target temperature quantization value En and the current temperature quantization value En0 to obtain the temperature error value. En.

[0077] when When En > 0, the current temperature is lower than the target temperature, and heating is required; when When En<0, the current temperature is higher than the target temperature, requiring cooling; when... When En = 0, the temperature reaches a steady state.

[0078] Temperature error value En, as the core input parameter of the PID algorithm, directly determines the adjustment direction (heating or cooling) and the intensity of the voltage output, providing a precise basis for the subsequent analog-to-digital conversion module to generate the control voltage and ensuring the accuracy of the adjustment process. By calculating the error value in real time and combining it with the PI control algorithm, the TEC drive voltage is dynamically adjusted, shortening the response time from the error state to the steady state and achieving rapid convergence.

[0079] 30: When the temperature error is greater than the preset error threshold, a drive adjustment signal is generated based on the temperature error to adjust the temperature of the semiconductor cooler (TEC).

[0080] The temperature control unit will calculate the temperature error value. If En is compared with a preset threshold, then... If En > 0, meaning the current temperature is lower than the target temperature, a positive pressure drive signal needs to be generated; if If En < 0, meaning the current temperature is higher than the target temperature, a negative pressure drive signal needs to be generated. (Based on temperature error value) En and the cumulative error value ΣE are used to calculate the voltage setpoint quantization value of the driving regulation signal through a PI control algorithm.

[0081] By dynamically adjusting the drive signal strength in real time using a PI algorithm, combined with the fast current response of the push-pull circuit to shorten the response time, the temperature adjustment time from the error state to the steady state is reduced, thus meeting the fast response requirements of laser frequency doubling crystals. Furthermore, step 30 also includes the following steps: 31: Based on the sign of the temperature error, confirm the quantized value of the voltage setpoint and the direction of the drive adjustment signal.

[0082] Specifically, the formula for calculating the voltage setpoint quantization value is as follows:

[0083] Among them, V n A quantized value, ΔE, is given for the voltage. n For temperature error, ; E is the cumulative value of temperature error. , of which E n For the target temperature value, E n0 This is the current temperature value. (K) p1 For temperature-voltage output proportional gain, K i1 This is the integral gain of the temperature-voltage output.

[0084] 32: Based on the given voltage quantization value, output the corresponding drive adjustment signal in the direction.

[0085] This application also provides a laser device, which includes a laser, a thermoelectric cooler (TEC), and a temperature control device as described above, wherein the thermoelectric cooler (TEC) is used to regulate the operating temperature of the laser.

[0086] The laser device mainly consists of three parts: a laser, a thermoelectric cooler (TEC), and a temperature control device. The TEC serves as the core temperature control actuator, and through the precise regulation of the temperature control device, it achieves stable operating temperature of the laser.

[0087] By collaboratively designing the laser, thermoelectric cooler (TEC), and temperature control device, the temperature sensitivity issue of the frequency doubling crystal is resolved, ensuring stable wavelength and reliable power output of the laser in industrial, medical, and military fields. The temperature control device, as the core component, uses precise temperature acquisition, error calculation, and drive adjustment to enable the TEC to efficiently regulate the laser's operating temperature, ultimately achieving high precision and stability in laser performance.

[0088] Unlike existing technologies, this application overcomes the limitations of voltage and current, ripple interference, and response speed bottlenecks of traditional semiconductor cooler (TEC) temperature control solutions through the synergy of modular hardware design and dynamic control algorithms. Ultimately, it achieves high-precision, fast-response, and wide-compatibility temperature control of laser frequency doubling crystals, solving the temperature control problem of high-power lasers.

[0089] Specifically, this application provides a bipolar voltage output design for the digital-to-analog converter module, which directly controls the heating / cooling direction of the thermoelectric cooler (TEC), solving the problem that traditional unipolar drives cannot simultaneously handle heating and cooling, and achieving bidirectional temperature regulation; the voltage gain amplification unit's wide-range voltage scaling is compatible with the power supply requirements of high-voltage TECs, and the voltage adjustment range covers the entire operating range of the TEC, improving system adaptability; the push-pull circuit of the current gain amplification unit provides high-current drive capability, solving the problem of slow response speed of low-voltage, low-current TECs, shortening the response time to the millisecond level; the linearization and high-precision signal processing of the temperature acquisition module achieve linear conversion between temperature and voltage signals, which, together with the analog-to-digital converter module, improves the temperature acquisition accuracy and solves the error problem caused by the nonlinearity of traditional acquisition.

[0090] Meanwhile, this application uses a PID control algorithm for dynamic error correction, with the proportional term quickly suppressing large errors and the integral term eliminating static errors, thus achieving rapid temperature convergence; the low-ripple drive of analog voltage control avoids high-frequency ripple conduction from the MOS switching circuit, improving the stability of temperature control.

[0091] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A temperature control device for a semiconductor cooler, characterized in that, include: A semiconductor cooler driving circuit, wherein the driving signal output terminal of the semiconductor cooler driving circuit is connected to the semiconductor cooler; A temperature regulation circuit, the output of which is connected to the semiconductor cooler drive circuit, is used to send an adjustment signal to the semiconductor cooler drive circuit according to the temperature of the semiconductor cooler.

2. The temperature control device according to claim 1, characterized in that, The semiconductor cooler drive circuit includes a digital-to-analog converter unit, a voltage gain amplifier unit, and a current gain amplifier unit. The input terminal of the digital-to-analog converter is connected to the output terminal of the temperature regulation circuit, the output terminal of the digital-to-analog converter is connected to the input terminal of the voltage gain amplifier unit, the output terminal of the voltage gain amplifier unit is connected to the input terminal of the current gain amplifier module, and the output terminal of the voltage gain amplifier unit is connected to the semiconductor cooler.

3. The temperature control device according to claim 2, characterized in that, The digital-to-analog conversion unit includes a positive and negative voltage conversion chip, a first operational amplifier, and a first capacitor; The first terminal of the positive-to-negative voltage conversion chip is connected to the first signal input terminal, the second terminal of the positive-to-negative voltage conversion chip is connected to the positive terminal of the first power supply, the third terminal of the positive-to-negative voltage conversion chip is connected to both the first terminal of the first capacitor and the first terminal of the first operational amplifier, the fourth terminal of the positive-to-negative voltage conversion chip is connected to both the second terminal of the first operational amplifier and the second terminal of the first capacitor, the fifth terminal of the positive-to-negative voltage conversion chip is connected to the third terminal of the first operational amplifier, and the sixth terminal of the positive-to-negative voltage conversion chip is grounded. The fourth terminal of the first operational amplifier is connected to the positive terminal of the first power supply, the fifth terminal of the first operational amplifier is connected to the negative terminal of the first power supply, and the first terminal of the first operational amplifier serves as the output terminal of the digital-to-analog converter unit.

4. The temperature control device according to claim 2, characterized in that, The voltage gain amplification unit includes a second operational amplifier, a first resistor, and a second resistor; The first terminal of the second operational amplifier serves as the input terminal of the voltage gain amplification unit. The second terminal of the second operational amplifier is connected to both the first terminal of the first resistor and the first terminal of the second resistor. The third terminal of the second operational amplifier is connected to the second terminal of the second resistor and serves as the output terminal of the voltage gain amplification unit. The fourth terminal of the second operational amplifier is connected to the positive terminal of the second power supply. The fifth terminal of the second operational amplifier is connected to the negative terminal of the second power supply. The second terminal of the first resistor is grounded.

5. The temperature control device according to claim 2, characterized in that, The current gain amplification unit includes a first transistor and a second transistor; The first end of the first transistor is connected to the first end of the second transistor, and together they serve as the input terminal of the current gain amplification unit. The second end of the first transistor is connected to the positive terminal of the second power supply. The third end of the first transistor is connected to the second end of the second transistor, and together they serve as the output terminal of the current gain amplification unit. The third end of the second transistor is connected to the negative terminal of the second power supply.

6. The temperature control device according to claim 1, characterized in that, The temperature regulation circuit includes a processor, a thermistor, a third operational amplifier, a second capacitor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, and a seventh resistor. The first terminal of the third operational amplifier is simultaneously connected to the first terminal of the sixth resistor and the input terminal of the processor. The second terminal of the third operational amplifier is simultaneously connected to the first terminal of the thermistor, the first terminal of the second capacitor, the first terminal of the fourth resistor, and the first terminal of the third resistor. The third terminal of the third operational amplifier is simultaneously connected to the first terminal of the fifth resistor, the first terminal of the seventh resistor, and the second terminal of the sixth resistor. The fourth terminal of the third operational amplifier is connected to the positive terminal of the third power supply, and the fifth terminal of the third operational amplifier is connected to the negative terminal of the third power supply. The second end of the thermistor, the second end of the second terminal, and the second end of the fourth resistor are all grounded. The second end of the third resistor is simultaneously connected to the second end of the fifth resistor and the second signal input terminal. The second end of the seventh resistor is grounded. The output terminal of the processor serves as the output terminal of the temperature regulation circuit.

7. A temperature control method for a semiconductor cooler, used in the temperature control device as described in any one of claims 1-6, characterized in that, include: Collect the current temperature value of the semiconductor cooler; Calculate the temperature error between the current temperature value and the target temperature value; When the temperature error exceeds a preset error threshold, a drive adjustment signal is generated based on the temperature error to adjust the temperature of the semiconductor cooler.

8. The temperature control method for a semiconductor cooler according to claim 7, characterized in that, The acquisition of the current temperature value of the semiconductor cooler includes: The temperature of the semiconductor cooler is converted into a temperature voltage signal using a thermistor; The temperature voltage signal level is quantized into the current temperature value.

9. The temperature control method for a semiconductor cooler according to claim 7, characterized in that, The generation of the drive adjustment signal based on the temperature error includes: Based on the sign of the temperature error, confirm the quantized value of the voltage setpoint and the direction of the drive adjustment signal; Based on the given quantized value of the voltage, a drive adjustment signal in the corresponding direction is output.

10. The temperature control method for a semiconductor cooler according to claim 9, characterized in that, The formula for calculating the given voltage quantization value is as follows: Among them, V n A quantized value, ΔE, is given for the voltage. n For temperature error, E is the cumulative temperature error, K p1 For temperature-voltage output proportional gain, K i1 This is the integral gain of the temperature-voltage output.

11. A laser device, characterized in that, The laser device includes a laser, a semiconductor cooler, and a temperature control device as described in any one of claims 1 to 6, wherein the semiconductor cooler is used to regulate the operating temperature of the laser.

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