Semiconductor heating and cooling chip driving circuit and device based on analog signal control

Abstract

The present invention provides a semiconductor heating and cooling sheet driving circuit and device based on analog signal control, the circuit comprises: a temperature detection feedback module, an adjustment module, a temperature control module, and an H-bridge module, the temperature control module is respectively connected to the temperature detection feedback module, the adjustment module and the H-bridge module, and the H-bridge module is connected to the adjustment module; the temperature detection feedback module is used to form a feedback voltage according to the current temperature of the target detection area, the adjustment module is used to form an adjustment voltage according to the current of the H-bridge module, the temperature control module is used to output a control signal to the H-bridge module according to the feedback voltage and the adjustment voltage, and the control signal is used to control the current size and direction of the external semiconductor heating and cooling sheet connected to the H-bridge module so that the temperature of the target detection area is maintained at the target temperature. The present invention improves the control effect of the external semiconductor heating and cooling sheet and avoids the noise caused by the digital signal.

Description

Technical Field

[0001] The present invention relates to the field of electronic technology, and in particular to a semiconductor heating and cooling plate driving circuit and device based on analog signal control. Background Art

[0002] Thermo Electron Cooler (TEC) is a device that uses the Peltier effect to achieve cooling and heating. The TEC drive circuit controls the direction of the current flowing through the TEC to switch between heating and cooling, and controls the current flowing through the TEC to achieve the best cooling or heating effect.

[0003] An existing semiconductor heating and cooling plate driving circuit uses 4 MOS tubes or 4 bipolar power transistors to form an H-bridge, and adjusts the waveform of the PWM signal through the feedback voltage obtained by the thermistor, and then controls the direction and magnitude of the current flowing through the semiconductor heating and cooling plate through the PWM signal, thereby achieving temperature adjustment. The driving circuit uses a PWM signal to control the H-bridge. The PWM signal is a pulse width modulation signal, which is a typical high-frequency digital signal. It will bring certain high-frequency noise to the circuit and is not suitable for applications that are sensitive to noise, such as narrow linewidth laser temperature control systems.

[0004] Another existing semiconductor heating and cooling plate driving circuit obtains feedback voltage through a thermistor, and then compares the feedback voltage with a reference voltage through a comparator, and controls the heating circuit or cooling circuit of the semiconductor heating and cooling plate according to the output result of the comparator. This driving circuit uses the feedback voltage to control the heating or cooling switching of the semiconductor heating and cooling plate, but cannot adjust the current size, and the cooling or heating effect is poor. Summary of the invention

[0005] The first object of the present invention is to provide a semiconductor heating and cooling plate driving circuit based on analog signal control which can avoid high-frequency noise caused by digital signals.

[0006] A second object of the present invention is to provide a laser device comprising the above-mentioned semiconductor heating and cooling plate driving circuit based on analog signal control.

[0007] In order to achieve the above-mentioned first purpose, the present invention provides a semiconductor heating and cooling plate driving circuit based on analog signal control, which includes: a temperature detection feedback module, an adjustment module, a temperature control module, and an H-bridge module, the temperature control module is respectively connected to the temperature detection feedback module, the adjustment module and the H-bridge module, and the H-bridge module is connected to the adjustment module; the temperature detection feedback module is used to form a feedback voltage according to the current temperature of the target detection area, the adjustment module is used to form an adjustment voltage according to the current of the H-bridge module, and the temperature control module is used to output a control signal to the H-bridge module according to the feedback voltage and the adjustment voltage, and the control signal is used to control the current size and direction of the external semiconductor heating and cooling plate connected to the H-bridge module so that the temperature of the target detection area is maintained at the target temperature.

[0008] As can be seen from the above scheme, the present invention detects the current temperature of the target detection area through the temperature detection feedback module to form a feedback voltage, the adjustment module forms an adjustment voltage according to the current of the H-bridge module, and the temperature control module adjusts the current size and direction of the H-bridge module in combination with the feedback voltage and the adjustment voltage, and controls the external semiconductor heating and cooling plate connected to the H-bridge module to heat or cool. The present invention converts the analog signal fed back by the temperature detection feedback module and the adjustment module into a control signal to control the external semiconductor heating and cooling plate, and achieves accurate adjustment of the temperature of the target detection area without using a PWM digital signal for control, avoiding the noise caused by the digital signal, and is convenient for application in circuit designs that have high requirements for noise indicators. In addition, the present invention combines the feedback voltage and the adjustment voltage to adjust the current size, which can more efficiently adjust the current size of the H-bridge module, improve the heating and cooling effects of the external semiconductor heating and cooling plate, and make the temperature of the target detection area return to the set target temperature faster.

[0009] A further solution is that the H-bridge module includes a first switch tube, a second switch tube, a first current control tube, a second current control tube, and a current sampling resistor; the temperature control module is respectively connected to the control end of the first switch tube, the control end of the second switch tube, the control end of the first current control tube, and the control end of the second current control tube; a first current branch is formed between the first switch tube, the external semiconductor heating and cooling sheet, and the second current control tube, and a second current branch is formed between the second switch tube, the external semiconductor heating and cooling sheet, and the first current control tube; the current sampling resistor is respectively connected to the first current branch, the second current branch, and the adjustment module.

[0010] It can be seen that by providing a current sampling resistor connecting the first current branch and the second current branch, the adjustment voltage formed by the adjustment module can better reflect the current condition of the H-bridge module, thereby more efficiently adjusting the current size of the H-bridge module.

[0011] A further solution is that the first switch tube and the second switch tube are both PMOS tubes, and the first current control tube and the second current control tube are both triodes.

[0012] It can be seen that the use of PMOS tubes for switching tubes facilitates the setting of switches, and the use of triodes for current control tubes can reduce the requirements for driving voltage compared to MOS tubes.

[0013] A further solution is that the temperature control module includes a first amplifying unit, a second amplifying unit, a first comparator and a second comparator; the first amplifying unit includes a first operational amplifier, a non-inverting input terminal of the first operational amplifier receives a first feedback voltage from the temperature detection feedback module, an inverting input terminal of the first operational amplifier receives a regulating voltage from the regulating module, and an output terminal of the first operational amplifier is connected to a control terminal of a second current control tube; the second amplifying unit includes a second operational amplifier, a non-inverting input terminal of the second operational amplifier receives a second feedback voltage from the temperature detection feedback module, an inverting input terminal of the second operational amplifier receives a regulating voltage from the regulating module, and an output terminal of the second operational amplifier is connected to the control terminal of the first current control tube; the non-inverting input terminal of the first comparator is connected to the output terminal of the first operational amplifier, the inverting input terminal of the first comparator is connected to the output terminal of the second operational amplifier, and the output terminal of the first comparator is connected to the control terminal of the first switch tube; the non-inverting input terminal of the second comparator is connected to the output terminal of the second operational amplifier, the inverting input terminal of the second comparator is connected to the output terminal of the first operational amplifier, and the output terminal of the second comparator is connected to the control terminal of the second switch tube.

[0014] It can be seen that the first feedback voltage and the regulating voltage are converted into voltages for controlling the first switch tube and the second current control tube according to a certain relationship, and the second feedback voltage and the regulating voltage are converted into voltages for controlling the second switch tube and the first current control tube according to a certain relationship.

[0015] A further solution is that the temperature detection feedback module includes a third amplifying unit, a fourth amplifying unit, and a fifth amplifying unit; the third amplifying unit includes a thermistor, a first resistor, and a third operational amplifier, the in-phase input terminal of the third operational amplifier receives the first reference voltage, the inverting input terminal of the third operational amplifier is connected to the second end of the thermistor and the first end of the first resistor, the first end of the thermistor is connected to the temperature setting voltage terminal, the second end of the first resistor is connected to the output terminal of the third operational amplifier, and the output terminal of the third operational amplifier outputs the temperature detection voltage; the fourth amplifying unit outputs a first feedback voltage after receiving the temperature detection voltage, and the fifth amplifying unit outputs a second feedback voltage after receiving the first feedback voltage; when the current temperature of the target detection area is equal to the target temperature corresponding to the temperature setting voltage terminal, the first feedback voltage, the second reference voltage, and the second feedback voltage are equal; when the current temperature of the target detection area is greater than the target temperature corresponding to the temperature setting voltage terminal, the first feedback voltage is less than the second reference voltage, and the second reference voltage is less than the second feedback voltage; when the current temperature of the target detection area is less than the target temperature corresponding to the temperature setting voltage terminal, the first feedback voltage is greater than the second reference voltage, and the second reference voltage is greater than the second feedback voltage.

[0016] It can be seen that by setting the thermistor to reflect the temperature change of the target detection area, the first feedback voltage and the second feedback voltage are obtained according to the temperature change, and the current of the H-bridge module is adjusted based on the first feedback voltage and the second feedback voltage.

[0017] A further solution is that the fourth amplification unit includes a fourth op amp, a second resistor, a third resistor, and a first capacitor, the non-inverting input terminal of the fourth op amp receives the second reference voltage, the inverting input terminal of the fourth op amp is respectively connected to the second end of the second resistor and the first end of the third resistor, the first end of the second resistor is connected to the output terminal of the third op amp, the second end of the third resistor is connected to the first end of the first capacitor, and the second end of the first capacitor is connected to the output terminal of the fourth op amp.

[0018] It can be seen that the second resistor and the first capacitor form an integration circuit to ensure the response speed and stability of the temperature detection voltage being converted into the first feedback voltage.

[0019] A further solution is that the semiconductor heating and cooling plate driving circuit based on analog signal control also includes an overvoltage protection module, and the temperature detection feedback module is connected to the temperature control module through the overvoltage protection module; the overvoltage protection module is used to limit the feedback voltage according to the temperature detection voltage, and the temperature control module is used to output a control signal to the H-bridge module based on the feedback voltage and the adjustment voltage after being limited by the overvoltage protection module.

[0020] It can be seen that by setting up an overvoltage protection module, it is possible to prevent the first feedback voltage and the second feedback voltage from being too large when the current temperature of the target detection area measured by the thermistor is very different from the target temperature and the temperature detection voltage is very large compared to the target voltage when the temperature is balanced.

[0021] A further solution is that the overvoltage protection module includes an analog switch unit, a third comparator, a fourth comparator, a sixth amplifying unit, and a seventh amplifying unit. The analog switch unit is respectively connected to the output end of the third comparator, the output end of the fourth comparator, the sixth amplifying unit, and the seventh amplifying unit. The analog switch unit receives a first feedback voltage, a second feedback voltage, a third reference voltage, and a fourth reference voltage; the third comparator is used to compare the temperature detection voltage and the first threshold voltage, and the fourth comparator is used to compare the temperature detection voltage and the second threshold voltage; the analog switch unit is used to select the second feedback voltage or the third reference voltage to enter the sixth amplifying unit according to the output of the third comparator, and is used to select the first feedback voltage or the fourth reference voltage to enter the seventh amplifying unit according to the output of the fourth comparator; the sixth amplifying unit is used to output the second feedback voltage after limitation, and the seventh amplifying unit is used to output the first feedback voltage after limitation.

[0022] It can be seen that the limitation of the first feedback voltage and the second feedback voltage can be conveniently achieved by using the analog switch unit.

[0023] A further solution is that the regulation module includes an eighth amplification unit, the eighth amplification unit includes an eighth op amp and a negative feedback branch of the eighth op amp, the non-inverting input terminal of the eighth op amp receives the sampling voltage corresponding to the current sampling resistor and the fifth reference voltage, the inverting output terminal of the eighth op amp is connected to the output terminal of the eighth op amp through the negative feedback branch of the eighth op amp, and the output terminal of the eighth op amp outputs the regulation voltage.

[0024] It can be seen that by setting the fifth reference voltage to ensure the regulated voltage, the first current control tube and the second current control tube are turned on at the same time.

[0025] In order to achieve the second objective mentioned above, the present invention provides a laser device, comprising a housing, wherein the housing comprises the semiconductor heating and cooling plate driving circuit based on analog signal control as mentioned above. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is an overall structural block diagram of an embodiment of a semiconductor heating and cooling plate driving circuit based on analog signal control of the present invention.

[0027] Figure 2 It is a circuit schematic diagram of an H-bridge module in an embodiment of a semiconductor heating and cooling plate driving circuit based on analog signal control of the present invention.

[0028] Figure 3It is a circuit schematic diagram of a temperature control module in an embodiment of a semiconductor heating and cooling plate driving circuit based on analog signal control of the present invention.

[0029] Figure 4 It is a circuit schematic diagram of a temperature detection feedback module in an embodiment of a semiconductor heating and cooling plate driving circuit based on analog signal control of the present invention.

[0030] Figure 5 It is a circuit schematic diagram of an overvoltage protection module in an embodiment of a semiconductor heating and cooling plate driving circuit based on analog signal control of the present invention.

[0031] Figure 6 It is a circuit schematic diagram of an adjustment module in an embodiment of a semiconductor heating and cooling plate driving circuit based on analog signal control of the present invention.

[0032] The present invention is further described below in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0033] The semiconductor heating and cooling sheet driving circuit based on analog signal control of the present invention controls the current magnitude and direction of the external semiconductor heating and cooling sheet connected to the H-bridge module according to the feedback voltage corresponding to the current temperature of the target detection area and the adjustment voltage corresponding to the current of the H-bridge module. The present invention also provides a laser device including the semiconductor heating and cooling sheet driving circuit controlled by analog signal.

[0034] Embodiment of semiconductor heating and cooling film driving circuit based on analog signal control:

[0035] See also Figure 1 The semiconductor heating and cooling plate driving circuit 1 based on analog signal control includes a temperature detection feedback module 11, an overvoltage protection module 12, a regulation module 13, a temperature control module 14, and an H-bridge module 15.

[0036] The temperature detection feedback module 11 is connected to the overvoltage protection module 12. The overvoltage protection module 12, the adjustment module 13, and the H-bridge module 15 are respectively connected to the temperature control module 14. The H-bridge module 15 is connected to the adjustment module 13. The H-bridge module 15 is connected to the external semiconductor heating and cooling sheet 2.

[0037] The temperature detection feedback module 11 is used to form a feedback voltage according to the current temperature of the target detection area. The adjustment module 13 is used to form an adjustment voltage according to the current of the H-bridge module 15. The overvoltage protection module 12 is used to limit the adjustment voltage according to the temperature detection voltage. The temperature control module 14 is used to output a control signal to the H-bridge module according to the feedback voltage after the overvoltage protection module 12 is limited and the adjustment voltage formed by the adjustment module 13. The control signal is used to control the current size and direction of the external semiconductor heating and cooling plate 2 connected to the H-bridge module 15 so that the temperature of the target detection area is maintained at the target temperature. The external semiconductor heating and cooling plate 2 is used to adjust the temperature of the target detection area by heating or cooling.

[0038] See also Figure 2 The H-bridge module 15 includes a first switch tube Q1, a second switch tube Q3, a first current control tube Q2, a second current control tube Q4, and a current sampling resistor R18. The temperature control module 14 is respectively connected to the control end G1 of the first switch tube, the control end G3 of the second switch tube, the control end B2 of the first current control tube, and the control end B4 of the second current control tube.

[0039] In this embodiment, the first switch tube Q1 and the second switch tube Q3 are both PMOS tubes, and the first current control tube Q2 and the second current control tube Q4 are both triodes. The control terminal G1 of the first switch tube is the gate of the first switch tube Q1. The control terminal G3 of the second switch tube is the gate of the second switch tube Q3. The control terminal B2 of the first current control tube is the base of the first current control tube Q2. The control terminal B4 of the second current control tube is the base of the second current control tube Q4.

[0040] The external semiconductor heating refrigeration sheet 2 is arranged between OUT- and OUT+. A first current branch is formed between the first switch tube Q1, the external semiconductor heating refrigeration sheet 2 and the second current control tube Q4. A second current branch is formed between the second switch tube Q3, the external semiconductor heating refrigeration sheet 2 and the first current control tube Q2. The current sampling resistor R18 is respectively connected to the first current branch, the second current branch and the adjustment module 13.

[0041] See also Figure 3 The temperature control module 14 includes a first amplifying unit, a second amplifying unit, a first comparator OA1 and a second comparator OA2.

[0042] The first amplification unit includes a first operational amplifier U1, a nineteenth resistor R19, a twentieth resistor R20, and a twenty-first resistor R21. The non-inverting input terminal of the first operational amplifier U1 receives the limited first feedback voltage A from the overvoltage protection module 12. The inverting input terminal of the first operational amplifier U1 is connected to the first end of the nineteenth resistor R19, and receives the adjustment voltage V_fb from the adjustment module 13 via the twenty-first resistor R21. The second end of the nineteenth resistor R19 is connected to the control end B4 of the second current control tube and is connected to the output end of the first operational amplifier U1 via the twentieth resistor R20. The output end of the first operational amplifier U1 is connected to the control end B4 of the second current control tube via the twentieth resistor R20. The first end of the nineteenth resistor R19, that is, the end of the nineteenth resistor R19 close to the twenty-first resistor R21, and the second end of the nineteenth resistor R19, that is, the end of the nineteenth resistor R19 far away from the twenty-first resistor R21.

[0043] The second amplification unit includes a second operational amplifier U2, a twenty-first resistor R22, a twenty-third resistor R23, and a twenty-fourth resistor R24. The in-phase input terminal of the second operational amplifier U2 receives the limited second feedback voltage B from the overvoltage protection module 12. The inverting input terminal of the second operational amplifier is connected to the first end of the twenty-second resistor R22, and receives the adjustment voltage V_fb from the adjustment module 13 via the twenty-fourth resistor R24. The second end of the twenty-second resistor R22 is connected to the control end B2 of the first current control tube and is connected to the output end of the second operational amplifier U2 via the twenty-third resistor. The output end of the second operational amplifier U2 is connected to the control end B2 of the first current control tube via the twenty-third resistor R23. The first end of the twenty-second resistor R22, that is, the end of the twenty-second resistor R22 close to the twenty-fourth resistor R24, and the second end of the twenty-second resistor R22, that is, the end of the twenty-second resistor R2 far away from the twenty-fourth resistor R24.

[0044] The non-inverting input terminal of the first comparator OA1 is connected to the output terminal of the first operational amplifier U1, and receives the voltage signal A_compare outputted from the output terminal of the first operational amplifier U1. The inverting input terminal of the first comparator OA1 is connected to the output terminal of the second operational amplifier U2, and receives the voltage signal B_compare outputted from the output terminal of the second operational amplifier U2. The output terminal of the first comparator OA1 is connected to the control terminal G1 of the first switch tube.

[0045] The non-inverting input terminal of the second comparator OA2 is connected to the output terminal of the second operational amplifier U2, and receives the voltage signal B_compare outputted from the output terminal of the second operational amplifier U2. The inverting input terminal of the second comparator OA2 is connected to the output terminal of the first operational amplifier, and receives the voltage signal A_compare outputted from the output terminal of the first operational amplifier U1. The output terminal of the second comparator OA2 is connected to the control terminal G3 of the second switch tube.

[0046] See also Figure 4The temperature detection feedback module 11 includes a third amplifying unit, a fourth amplifying unit, and a fifth amplifying unit.

[0047] The third amplification unit includes a thermistor Rt, a first resistor R1, and a third operational amplifier U3. The non-inverting input terminal of the third operational amplifier U3 receives a first reference voltage Vref_1. The inverting input terminal of the third operational amplifier U3 is connected to the second end of the thermistor Rt and the first end of the first resistor R1. The first end of the thermistor Rt is connected to the temperature setting voltage terminal Vt. The second end of the first resistor R1 is connected to the output terminal of the third operational amplifier U3. The output terminal of the third operational amplifier U3 outputs a temperature detection voltage Vrt. The temperature setting voltage terminal Vt provides a temperature setting voltage, and the size of the temperature setting voltage terminal Vt determines the target temperature set for the target detection area. The temperature setting voltage terminal Vt is set according to actual needs. According to the semiconductor heating and cooling plate driving circuit based on analog signal control of this embodiment, the external semiconductor heating and cooling plate 2 at the target detection area can be controlled to heat or cool, so that the temperature at the target detection area is maintained at the target temperature value corresponding to the temperature setting voltage terminal Vt.

[0048] The first end of the thermistor Rt is an end of the thermistor Rt away from the first resistor R1, and the second end of the thermistor Rt is an end of the thermistor Rt close to the first resistor R1. The first end of the first resistor R1 is an end of the first resistor R1 away from the output end of the third operational amplifier U3, and the second end of the first resistor R1 is an end of the first resistor R1 close to the output end of the third operational amplifier U3.

[0049] The fourth amplification unit includes a second resistor R2, a third resistor R3, a fourth operational amplifier U4 and a first capacitor C1. The non-inverting input terminal of the fourth operational amplifier U4 receives the second reference voltage Vref_2. The inverting input terminal of the fourth operational amplifier U4 is respectively connected to the second end of the second resistor R2 and the first end of the third resistor R3. The first end of the second resistor R2 is connected to the output end of the third operational amplifier U3 and the second end of the first resistor R1. The second end of the third resistor R3 is connected to the first end of the first capacitor C1, and the second end of the first capacitor C1 is connected to the output end of the fourth operational amplifier U4. The output end of the fourth operational amplifier U4 outputs the first feedback voltage A_1.

[0050] The first end of the second resistor R2 is the end of the second resistor R2 close to the output end of the third operational amplifier U3, and the second end of the second resistor R2 is the end of the second resistor R2 away from the output end of the third operational amplifier U3. The first end of the third resistor R3 is the end of the third resistor R3 close to the inverting input end of the fourth operational amplifier U4, and the second end of the third resistor R3 is the end of the third resistor R3 away from the inverting input end of the fourth operational amplifier U4. The first end of the first capacitor C1 is the end of the first capacitor C1 away from the output end of the fourth operational amplifier U4, and the second end of the first capacitor C1 is the end of the first capacitor C1 close to the output end of the fourth operational amplifier U4.

[0051] The fifth amplification unit includes a fourth resistor R4, a fifth resistor R5, and a fifth operational amplifier U5. The non-inverting input terminal of the fifth operational amplifier U5 receives the second reference voltage Vref_2. The inverting input terminal of the fifth operational amplifier U5 is respectively connected to the second end of the fourth resistor R4 and the first end of the fifth resistor R5. The first end of the fourth resistor R4 is connected to the output terminal of the fourth operational amplifier U4 and the second end of the first capacitor C1. The second end of the fifth resistor R5 is connected to the output terminal of the fifth operational amplifier U5. The output terminal of the fifth operational amplifier U5 outputs the second feedback voltage B_1.

[0052] The first end of the fourth resistor R4, i.e., the end of the fourth resistor R4 far from the inverting input end of the fifth operational amplifier U5, and the second end of the fourth resistor R4, i.e., the end of the fourth resistor R4 close to the inverting input end of the fifth operational amplifier U5. The first end of the fifth resistor R5, i.e., the end of the fifth resistor R5 far from the output end of the fifth operational amplifier U5, and the second end of the fifth resistor R5, i.e., the end of the fifth resistor R5 close to the output end of the fifth operational amplifier U5.

[0053] The fourth amplifying unit is used to output a first feedback voltage A_1 after receiving the temperature detection voltage Vrt. The fifth amplifying unit is used to output a second feedback voltage B_1 after receiving the first feedback voltage.

[0054] When the current temperature of the target detection area is equal to the target temperature corresponding to the temperature setting voltage terminal Vt, the first feedback voltage A_1, the second reference voltage Vref_2, and the second feedback voltage A_2 are equal. When the current temperature of the target detection area is greater than the target temperature corresponding to the temperature setting voltage terminal, the first feedback voltage A_1 is less than the second reference voltage Vref_2, and the second reference voltage Vref_2 is less than the second feedback voltage B_1. When the current temperature of the target detection area is less than the target temperature corresponding to the temperature setting voltage terminal, the first feedback voltage A_1 is greater than the second reference voltage Vref_2, and the second reference voltage Vref_2 is greater than the second feedback voltage B_1.

[0055] See also Figure 5 The overvoltage protection module 12 includes an analog switch unit AS1, a third comparator OA3, a fourth comparator OA4, a sixth amplifying unit, and a seventh amplifying unit. The analog switch unit AS1 is connected to the output end of the third comparator OA3, the output end of the fourth comparator OA4, the sixth amplifying unit, and the seventh amplifying unit, respectively. The analog switch unit AS1 also receives a first feedback voltage A_1, a second feedback voltage B_1, a third reference voltage Vref_3, and a fourth reference voltage Vref_4. The second reference voltage Vref_2, the third reference voltage Vref_3, and the fourth reference voltage Vref_4 are equal.

[0056] The third comparator OA3 is used to compare the temperature detection voltage Vrt and the first set voltage Vtd_1 through the seventh resistor R7 and the ninth resistor R9 to obtain a first threshold voltage, and the fourth comparator is used to compare the temperature detection voltage Vrt and the second set voltage Vtd_2 through the tenth resistor R10 and the eleventh resistor R11 to obtain a second threshold voltage. The first set voltage Vtd_1 and the second set voltage Vtd_2 are equal.

[0057] The sixth amplifying unit includes a sixth resistor R6, an eighth resistor R8 and a sixth operational amplifier U6. The seventh amplifying unit includes a twelfth resistor R12, a thirteenth resistor R13 and a seventh operational amplifier U7.

[0058] The analog switch unit AS1 is used to select the second feedback voltage B_1 or the third reference voltage Vref_3 to enter the sixth amplification unit according to the output of the third comparator OA3, and is used to select the first feedback voltage A_1 or the fourth reference voltage Vref_4 to enter the seventh amplification unit according to the output of the fourth comparator OA4. The sixth amplification unit is used to output the second feedback voltage B after limitation, and the seventh amplification unit is used to output the first feedback voltage A after limitation.

[0059] Specifically, when the temperature detection voltage Vrt is less than the first threshold voltage, the third comparator OA3 outputs a low level, the analog switch unit AS1 selects the D1 pin and the S1 B pin, and the second feedback voltage B_1 enters the sixth amplification unit to obtain the limited second feedback voltage B; when the temperature detection voltage Vrt is greater than the first threshold voltage, the third comparator OA3 outputs a high level, the analog switch unit AS1 selects the D1 pin and the S1A pin, and the third reference voltage Vref_3 enters the sixth amplification unit to obtain the limited second feedback voltage B. Thus, when the temperature detection voltage Vrt is not less than the first threshold voltage, the limited second feedback voltage B is obtained by converting the second feedback voltage B_1 through the ratio set by the sixth amplification unit; when the temperature detection voltage Vrt is less than the first threshold voltage, the limited second feedback voltage B is a fixed value.

[0060] Specifically, when the temperature detection voltage Vrt is less than the second threshold voltage, the fourth comparator OA4 outputs a high level, the analog switch unit AS1 selects the D2 pin and the S2A pin, and the fourth reference voltage Vef_2 enters the seventh amplification unit to obtain the limited first feedback voltage A; when the temperature detection voltage Vrt is greater than the second threshold voltage, the fourth comparator OA4 outputs a low level, the analog switch unit AS1 selects the D2 pin and the S2B pin, and the fourth reference voltage Vref_4 enters the seventh amplification unit to obtain the limited first feedback voltage A. Thus, when the temperature detection voltage Vrt is greater than the second threshold voltage, the limited second feedback voltage A is obtained by converting the second feedback voltage A_1 through the ratio set by the seventh amplification unit; when the temperature detection voltage Vrt is less than the second threshold voltage, the limited first feedback voltage A is another fixed value.

[0061] The first feedback voltage A_1 and the second feedback voltage B_1 are limited by the overvoltage protection module 12, so that when the temperature detection voltage Vrt is within a certain voltage range, the limited first feedback voltage A is obtained by converting the first feedback voltage A_1 according to a certain ratio, and the limited second feedback voltage B is obtained by converting the second feedback voltage B_1 according to a certain ratio; when the temperature detection voltage Vrt is greater than the first threshold voltage, the limited second feedback voltage B is a fixed value; when the temperature detection voltage Vrt is less than the second threshold voltage, the limited second feedback voltage B is another fixed value.

[0062] See also Figure 6 , the regulating module 13 includes an eighth amplifying unit, the eighth amplifying unit includes an eighth operational amplifier U8, a sixteenth resistor R16, a seventeenth resistor R17 and a negative feedback branch of the eighth operational amplifier, and the negative feedback branch of the eighth operational amplifier includes a fourteenth resistor R14 and a fifteenth resistor R15. The in-phase input terminal of the eighth operational amplifier U8 receives the sampling voltage V_tec and the fifth reference voltage Vref_5 corresponding to the current sampling resistor R18, the inverting output terminal of the eighth operational amplifier U8 is connected to the output terminal of the eighth operational amplifier U8 through the negative feedback branch of the eighth operational amplifier U8, and the output terminal of the eighth operational amplifier outputs the regulating voltage V_fb. The regulating voltage V_fb is used to adjust the current magnitude of the first current branch and the second current branch in the H-bridge module 15. The fifth reference voltage Vref_5 is equal to the second reference voltage Vref_2.

[0063] When the current temperature of the target detection area is greater than the target temperature detected by the thermistor Rt, the limited first feedback voltage A is less than the limited second feedback voltage B, so that the first current control tube Q2 and the second switch tube Q3 are turned on, and the second current control tube Q4 and the first switch tube Q1 are disconnected. Under the action of the power supply terminal VCC, a current is generated along the second switch tube Q3 to the external semiconductor heating and cooling film 2, the external semiconductor heating and cooling film 2 to the first current control tube Q2, and the first current control tube Q2 to the current sampling resistor R18, so that the external semiconductor heating and cooling film 2 is cooled, thereby reducing the temperature of the target detection area. At the same time, the adjustment module 13 receives the sampling voltage V_tec corresponding to the current sampling resistor R18. Under the action of the sampling voltage V_tec, since the sampling voltage V_tec is initially small, the adjustment voltage V_fb will be reduced, thereby increasing the current input to the control terminal B2 of the first current control tube, thereby increasing the current flowing through the external semiconductor heating and cooling film 2. The increase of current flowing through the external semiconductor heating refrigeration plate 2 will increase the sampling voltage V_tec. After the sampling voltage increases, the adjustment voltage V_fb will increase, thereby reducing the current input to the control terminal B2 of the first current control tube, thereby increasing the current flowing through the external semiconductor heating refrigeration plate 2.

[0064] When the current temperature of the target detection area is less than the target temperature detected by the thermistor Rt, the first feedback voltage A after limitation is greater than the second feedback voltage B after limitation, so that the second current control tube Q4 and the first switch tube Q1 are turned on, the first current control tube Q2 and the second switch tube Q3 are turned off, and under the action of the power supply terminal VCC, a current is generated along the first switch tube Q1 to the external semiconductor heating and cooling film 2, the external semiconductor heating and cooling film 2 to the second current control tube Q4, and the second current control tube Q4 to the current sampling resistor R18, so that the external semiconductor heating and cooling film 2 is heated and the temperature of the target detection area is increased. At the same time, the adjustment module 13 receives the sampling voltage V_tec corresponding to the current sampling resistor R18. Under the action of the sampling voltage V_tec, since the sampling voltage V_tec is initially small, the adjustment voltage V_fb will be reduced, thereby increasing the current input to the control terminal B4 of the second current control tube, thereby increasing the current flowing through the external semiconductor heating and cooling film 2. The increase of current flowing through the external semiconductor heating refrigeration plate 2 will increase the sampling voltage V_tec. After the sampling voltage increases, the adjustment voltage V_fb will increase, thereby reducing the current input to the control terminal B4 of the second current control tube, thereby increasing the current flowing through the external semiconductor heating refrigeration plate 2.

[0065] When the current temperature of the target detection area detected by the thermistor Rt is equal to the target temperature, the limited first feedback voltage A, the limited second feedback voltage B, and the regulation voltage V_fb are equal, so that the first switch tube Q1, the first current control tube Q2, the second switch tube Q3, and the first current control tube Q2 are all disconnected.

[0066] Laser device embodiment:

[0067] This embodiment includes a shell, which includes a semiconductor heating refrigeration plate and a semiconductor heating refrigeration plate driving circuit based on analog signal control of the above embodiment. The semiconductor heating refrigeration plate is connected to the semiconductor heating refrigeration plate driving circuit based on analog signal control. Through the semiconductor heating refrigeration plate driving circuit based on analog signal control, the temperature of the target detection area adjusted by the semiconductor heating refrigeration plate is ensured to be maintained at the set target temperature.

[0068] In summary, the present invention converts the analog signal fed back by the temperature detection feedback module and the adjustment module into a control signal to control the external semiconductor heating and cooling plate, thereby accurately adjusting the temperature of the target detection area without using a PWM digital signal for control, thus avoiding the noise caused by the digital signal, and conveniently being applied in circuit designs that have high requirements for noise indicators. In addition, the present invention combines the feedback voltage and the adjustment voltage to adjust the current size, which can more efficiently adjust the current size of the H-bridge module, improve the heating and cooling effects of the external semiconductor heating and cooling plate, and make the temperature of the target detection area return to the set target temperature faster.

[0069] Finally, it should be emphasized that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention, such as not setting an overvoltage protection module, directly connecting the first feedback voltage to the non-inverting input terminal of the first operational amplifier and directly connecting the second feedback voltage to the non-inverting input terminal of the second operational amplifier, or both the first current control tube and the second current control tube use MOS tubes, etc., should be included in the protection scope of the present invention.

Claims

1. A semiconductor heating and cooling plate driving circuit based on analog signal control, characterized in that: include: A temperature detection feedback module, an adjustment module, a temperature control module, and an H-bridge module, wherein the temperature control module is respectively connected to the temperature detection feedback module, the adjustment module, and the H-bridge module, and the H-bridge module is connected to the adjustment module; The temperature detection feedback module is used to form a feedback voltage according to the current temperature of the target detection area, the adjustment module is used to form an adjustment voltage according to the current of the H-bridge module, and the temperature control module is used to output a control signal to the H-bridge module according to the feedback voltage and the adjustment voltage. The control signal is used to control the current size and direction of the external semiconductor heating and cooling plate connected to the H-bridge module so that the temperature of the target detection area is maintained at the target temperature.

2. The semiconductor heating and cooling sheet driving circuit based on analog signal control according to claim 1, characterized in that: The H-bridge module includes a first switch tube, a second switch tube, a first current control tube, a second current control tube, and a current sampling resistor, and the temperature control module is respectively connected to the control end of the first switch tube, the control end of the second switch tube, the control end of the first current control tube, and the control end of the second current control tube; A first current branch is formed between the first switch tube, the external semiconductor heating and cooling sheet and the second current control tube, a second current branch is formed between the second switch tube, the external semiconductor heating and cooling sheet and the first current control tube, and the current sampling resistor is respectively connected to the first current branch, the second current branch and the regulation module.

3. The semiconductor heating and cooling plate driving circuit based on analog signal control as claimed in claim 2, characterized in that: The first switch tube and the second switch tube are both PMOS tubes, and the first current control tube and the second current control tube are both triodes.

4. The semiconductor heating and cooling plate driving circuit based on analog signal control according to claim 2, characterized in that: The temperature control module includes a first amplifying unit, a second amplifying unit, a first comparator and a second comparator; The first amplifying unit comprises a first operational amplifier, a non-inverting input terminal of the first operational amplifier receives a first feedback voltage from the temperature detection feedback module, an inverting input terminal of the first operational amplifier receives the regulating voltage from the regulating module, and an output terminal of the first operational amplifier is connected to a control terminal of the second current control tube; The second amplifying unit comprises a second operational amplifier, a non-inverting input terminal of the second operational amplifier receives a second feedback voltage from the temperature detection feedback module, an inverting input terminal of the second operational amplifier receives the regulating voltage from the regulating module, and an output terminal of the second operational amplifier is connected to a control terminal of the first current control tube; The non-inverting input terminal of the first comparator is connected to the output terminal of the first operational amplifier, the inverting input terminal of the first comparator is connected to the output terminal of the second operational amplifier, and the output terminal of the first comparator is connected to the control terminal of the first switch tube; The non-inverting input terminal of the second comparator is connected to the output terminal of the second operational amplifier, the inverting input terminal of the second comparator is connected to the output terminal of the first operational amplifier, and the output terminal of the second comparator is connected to the control terminal of the second switch tube.

5. The semiconductor heating and cooling plate driving circuit based on analog signal control as claimed in claim 4, characterized in that: The temperature detection feedback module includes a third amplification unit, a fourth amplification unit, and a fifth amplification unit; The third amplification unit includes a thermistor, a first resistor, and a third operational amplifier, wherein a non-inverting input terminal of the third operational amplifier receives a first reference voltage, an inverting input terminal of the third operational amplifier is connected to a second terminal of the thermistor and a first terminal of the first resistor, the first terminal of the thermistor is connected to a temperature setting voltage terminal, a second terminal of the first resistor is connected to an output terminal of the third operational amplifier, and the output terminal of the third operational amplifier outputs a temperature detection voltage; The fourth amplifying unit outputs the first feedback voltage after receiving the temperature detection voltage, and the fifth amplifying unit outputs the second feedback voltage after receiving the first feedback voltage; When the current temperature of the target detection area is equal to the target temperature corresponding to the temperature setting voltage terminal, the first feedback voltage, the second reference voltage, and the second feedback voltage are equal; When the current temperature of the target detection area is greater than the target temperature corresponding to the temperature setting voltage end, the first feedback voltage is less than the second reference voltage, and the second reference voltage is less than the second feedback voltage; when the current temperature of the target detection area is less than the target temperature corresponding to the temperature setting voltage end, the first feedback voltage is greater than the second reference voltage, and the second reference voltage is greater than the second feedback voltage.

6. The semiconductor heating and cooling plate driving circuit based on analog signal control as claimed in claim 5, characterized in that: The fourth amplification unit includes a fourth operational amplifier, a second resistor, a third resistor, and a first capacitor. The non-inverting input terminal of the fourth operational amplifier receives the second reference voltage, the inverting input terminal of the fourth operational amplifier is respectively connected to the second end of the second resistor and the first end of the third resistor, the first end of the second resistor is connected to the output terminal of the third operational amplifier, the second end of the third resistor is connected to the first end of the first capacitor, and the second end of the first capacitor is connected to the output terminal of the fourth operational amplifier.

7. The semiconductor heating and cooling plate driving circuit based on analog signal control according to claim 5, characterized in that: Also includes: An overvoltage protection module, wherein the temperature detection feedback module is connected to the temperature control module via the overvoltage protection module; The overvoltage protection module is used to limit the feedback voltage according to the temperature detection voltage, and the temperature control module is used to output the control signal to the H-bridge module according to the feedback voltage limited by the overvoltage protection module and the regulation voltage.

8. The semiconductor heating and cooling plate driving circuit based on analog signal control according to claim 7, characterized in that: The overvoltage protection module includes an analog switch unit, a third comparator, a fourth comparator, a sixth amplifying unit, and a seventh amplifying unit, wherein the analog switch unit is respectively connected to the output end of the third comparator, the output end of the fourth comparator, the sixth amplifying unit, and the seventh amplifying unit, and the analog switch unit receives the first feedback voltage, the second feedback voltage, the third reference voltage, and the fourth reference voltage; The third comparator is used to compare the temperature detection voltage with the first threshold voltage, and the fourth comparator is used to compare the temperature detection voltage with the second threshold voltage; The analog switch unit is used for selecting the second feedback voltage or the third reference voltage to enter the sixth amplification unit according to the output of the third comparator, and for selecting the first feedback voltage or the fourth reference voltage to enter the seventh amplification unit according to the output of the fourth comparator; The sixth amplifying unit is used to output the limited second feedback voltage, and the seventh amplifying unit is used to output the limited first feedback voltage.

9. The semiconductor heating and cooling plate driving circuit based on analog signal control according to any one of claims 1 to 7, characterized in that: The regulating module includes an eighth amplifying unit, which includes an eighth operational amplifier and a negative feedback branch of the eighth operational amplifier. The non-inverting input terminal of the eighth operational amplifier receives the sampling voltage corresponding to the current sampling resistor and the fifth reference voltage. The inverting output terminal of the eighth operational amplifier is connected to the output terminal of the eighth operational amplifier through the negative feedback branch of the eighth operational amplifier, and the output terminal of the eighth operational amplifier outputs the regulating voltage.

10. A laser device, comprising a housing, characterized in that: The housing includes a semiconductor heating and cooling plate driving circuit based on analog signal control as described in any one of claims 1 to 9 above.

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