Laser TEC driving device and method

Abstract

The invention relates to the technical field of simulation optical fiber communication, in particular to a laser TEC driving device and method.The device comprises a first comparator, a second comparator, a voltage follower, a reverse proportional amplifier, a summator, an H bridge, a laser TEC and an output voltage adjustable DC-DC chip; the first comparator and the second comparator compare the voltage VB, when the VB is less than 0, the current direction of the laser refrigerator flows from the pin 1 to the pin 2, and the current magnitude is determined by the VB and is approximately equal to the value obtained by dividing the VB by the internal resistance of the TEC; according to the design of the laser, when the current flows from the second pin to the first pin, refrigeration is achieved, when the current flows from the first pin to the second pin, heating is achieved, switching of refrigeration and heating of the laser can be completed by changing the polarity of VB voltage, and the intensity of refrigeration (heating) can be completed by changing the magnitude of the VB voltage.

Description

Technical Field

[0001] This invention relates to the field of analog fiber optic communication technology, and in particular to a laser TEC driving device and method. Background Technology

[0002] With the development of communication technology, the frequency of signals used in communication is getting higher and higher, the transmission distance is getting longer and longer, and the requirements for signal quality are getting higher and higher. Using optical fiber to transmit analog radio frequency signals can greatly reduce transmission loss and improve signal transmission quality.

[0003] In analog fiber optic communication systems, the analog laser is a core component that directly affects the communication quality of the system. To ensure that the laser has a good noise figure and expected lifespan, its temperature needs to be maintained at around 25°C. The laser itself generally has a thermoelectric cooler (TEC), which is made using the Peltier effect of semiconductor materials. When the laser tube (LD) of the laser operates at around 25°C, the TEC does not work; when the LD's operating temperature rises, the drive circuit controls the TEC to start cooling, restoring the LD's temperature to around 25°C; when the LD's operating temperature drops, the drive circuit controls the TEC to start heating, restoring the LD's temperature to around 25°C.

[0004] Currently, most TEC drives and controls use dedicated chips, such as ADN8834 and ADN8835, with drive currents of 1.5A and 3A respectively. Since dedicated chips have integrated all functions and all performance characteristics, in special applications (such as drive current greater than 4A), it is necessary to develop new chips, which is too costly. Summary of the Invention

[0005] To achieve the above objectives, the technical solution for realizing the objectives of this invention is as follows:

[0006] VB is the error voltage control signal of the thermistor in the laser. When the thermistor is working at 25℃, VB=0V, when it is working at a temperature greater than 25℃, VB>0V, and when it is working at a temperature less than 25℃, VB<0V.

[0007] A laser thermoelectric cooler (TEC) driving device is characterized in that the device comprises a first comparator, a second comparator, a voltage follower, an inverting proportional amplifier, an adder, an H-bridge, a laser thermoelectric cooler (TEC), and an output voltage adjustable DC-DC chip. The operational amplifier chips used in the first comparator, the second comparator, the voltage follower, the inverting proportional amplifier, and the adder are all dual-rail-to-rail operational amplifiers, and each operational amplifier chip contains two sets of operational amplifiers; the H-bridge is composed of two N-channel / P-channel dual-channel MOSFETs.

[0008] The first comparator includes a first operational amplifier U1A, resistors R3, R4, and R7. Pin 8 of the first operational amplifier U1A is connected to +5V, and pin 4 is connected to -5V. One end of resistor R3 is connected to the error voltage port VB, and the other end of resistor R3 is connected to pin 3 of the first operational amplifier U1A. One end of resistor R4 is connected to ground, and the other end of resistor R4 is connected to pin 2 of the first operational amplifier U1A. Pin 1 of the operational amplifier U1A is connected to one end of resistor R7, and the other end of resistor R7 is connected to the two gates G1 and G2 of the field-effect transistor MOSFET1 in the H-bridge. The resistance values ​​of resistors R3 and R4 are 10kΩ, and the resistance value of resistor R7 is 100Ω.

[0009] The second comparator includes a second operational amplifier U1B, resistors R5, R6, and R8. Pin 8 of the second operational amplifier U1B is connected to +5V, and pin 4 is connected to -5V. One end of resistor R6 is connected to the error voltage port VB, and the other end of resistor R6 is connected to pin 6 of the first operational amplifier U1B. One end of resistor R5 is connected to ground, and the other end of resistor R5 is connected to pin 5 of the first operational amplifier U1B. Pin 7 of the operational amplifier U1B is connected to one end of resistor R8, and the other end of resistor R8 is connected to the two gates G1 and G2 of the field-effect transistor MOSFET2 in the H-bridge. The resistance values ​​of resistors R5 and R6 are 10kΩ, and the resistance value of resistor R8 is 100Ω.

[0010] The H-bridge includes a first N / P dual-channel field-effect transistor MOSFET1, a second N / P dual-channel field-effect transistor MOSFET2, and a laser thermoelectric cooler TECU4. Pin 1 of MOSFET1 is grounded. Pin 2 of MOSFET1 is first shorted to pin 5 of MOSFET1 and then connected to one end of resistor R7 in the first comparator. Pin 3 of MOSFET1 is shorted to pin 6 of MOSFET2 and then connected to pin 1 of thermoelectric cooler TECU4. Pin 4 of MOSFET1 is connected to the voltage output port VT of the adjustable DC-DC chip U5. Pin 1 of MOSFET2 is grounded. Pin 2 of MOSFET2 is first shorted to pin 5 of MOSFET2 and then connected to one end of resistor R8 in the second comparator. Pin 3 of MOSFET2 is shorted to pin 6 of MOSFET2 and then connected to pin 2 of thermoelectric cooler TECU4. Pin 4 of MOSFET2 is connected to the voltage output port VT of the adjustable DC-DC chip U5.

[0011] The voltage follower includes a third operational amplifier U2A and a resistor R12. Pin 8 of the third operational amplifier U2A is connected to +5V and pin 4 is grounded. Pin 1 of the third operational amplifier U2A is shorted to pin 2 of U2A and then connected to one end of resistor R11 in the adder. The resistance of resistor R12 is 1kΩ.

[0012] The inverting proportional amplifier includes a fourth operational amplifier U2B, resistors R14, R16, R17, and R18. Pin 8 of the fourth operational amplifier U2B is connected to +5V, and pin 4 is grounded. One end of resistors R14 and R17 is connected in parallel, and the parallel end is connected to pin 6 of the fourth operational amplifier. The other end of resistor R14 is connected to pin 7 of the fourth operational amplifier and also to one end of resistor R13 in the adder. One end of resistor R16 is connected to the thermistor error voltage port VB, and the other end is connected to resistor R17. The other end of resistor R17 is connected to pin 6 of the fourth operational amplifier. One end of resistor R18 is connected to ground, and the other end is connected to pin 5 of the fourth operational amplifier. The resistance of resistor R14 is 100kΩ, the resistance of resistor R16 is 1kΩ, the resistance of resistor R17 is 100kΩ, and the resistance of resistor R18 is 10kΩ.

[0013] The adder includes a fifth operational amplifier, resistors R9, R10, R11, R13, and R15. Pin 8 of the fifth operational amplifier U3A is connected to +5V, and pin 4 is connected to -5V. One end of resistor R9 is connected in parallel with one end of resistors R10, R11, and R13, and this parallel connection is then connected to pin 2 of the fifth operational amplifier U3A. The other end of resistor R9 is connected to the fifth operational amplifier U3A and also to one end of resistor R2 in the DC-DC adjustable power supply. The other end of resistor R10 is connected to a -1.2V DC power supply. The other end of resistor R11 is connected to pin 1 of the third operational amplifier U2A in the voltage follower. The other end of resistor R13 is connected to pin 7 of the fourth operational amplifier U2B in the inverting proportional amplifier. One end of R15 is connected to ground, and the other end of R15 is connected to pin 3 of the fifth operational amplifier U3A in the adder. The resistance values ​​of resistors R9, R10, R11, and R13 are 100kΩ, and the resistance value of resistor R15 is 10kΩ.

[0014] Compared with traditional dedicated chips for TEC driving and control, this technical solution has the following characteristics:

[0015] For applications with special requirements (such as drive current greater than 4A), existing chips need to be redeveloped, which is too costly. Furthermore, these power supply chips operate on low-voltage DC power, with a maximum voltage of 5.5V. Therefore, in high-voltage DC power supply systems, secondary voltage regulation is required to ensure normal operation of the chip, inevitably leading to a decrease in power supply efficiency.

[0016] The beneficial effects of this invention are as follows:

[0017] 1. High efficiency: In high DC voltage power supply equipment, such as 12V or 24V DC power supply, a single-stage DC-DC drive can be used to drive the TEC. If a dedicated chip is used, such as the dedicated chip ADN8834 or ADN8835, the voltage needs to be stepped down to 5V by a single-stage DC-DC chip before driving the TEC through ADN8834. Therefore, the total efficiency is equal to the product of the efficiencies of the two chips. If the drive device of this invention is used, for example, using the Jiangsu Zhanxin XC8224 chip, the input voltage is 5V to 36V. Therefore, the DC-DC chip can be used directly to drive it. The total efficiency is equal to the efficiency of a single DC-DC chip, which is significantly higher than the total efficiency of using a dedicated chip.

[0018] 2. Large drive current. For example, using dedicated chips ADN8834 and ADN8835, the current is 1.5A and 3A respectively; if DC-DC direct drive is used, taking Jiangsu Zhanxin XC8224 as an example, the drive current can reach 8A.

[0019] 3. The device has a simple and practical architecture, consisting of a DC-DC chip, an operational amplifier, and a MOSFET. When there are special requirements for drive voltage and current, the DC-DC chip can be selected according to the specific requirements, without the need to redesign a dedicated chip. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0021] Figure 1 This is a schematic diagram of the laser TEC driving device according to an embodiment of the present invention.

[0022] Figure 2 This is a flowchart of a laser TEC driving method according to an embodiment of the present invention. Detailed Implementation

[0023] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0024] Please see Figure 1In a first aspect, the present invention provides a laser TEC driving device, comprising a first comparator, a second comparator, a voltage follower, an inverting proportional amplifier, an adder, an H-bridge, a laser thermoelectric cooler (TEC), and an output voltage adjustable DC-DC chip. The first comparator includes a first operational amplifier U1A, resistors R3, R4, and R7; the second comparator includes a second operational amplifier U1B, resistors R5, R6, and R8; the H-bridge includes a first N / P dual-channel field-effect transistor MOSFET1, a second N / P dual-channel field-effect transistor MOSFET2, and a laser thermoelectric cooler TECU4; the voltage follower includes a third operational amplifier U2A and resistor R12; the inverting proportional amplifier includes a fourth operational amplifier U2B, resistors R14, R16, R17, and R18; and the adder includes a fifth operational amplifier, resistors R9, R10, R11, R13, and R15.

[0025] Furthermore, pin 8 of the first operational amplifier U1A is connected to +5V, and pin 4 is connected to -5V. One end of resistor R3 is connected to the error voltage port VB, and the other end of resistor R3 is connected to pin 3 of the first operational amplifier U1A. One end of resistor R4 is connected to ground, and the other end of resistor R4 is connected to pin 2 of the first operational amplifier U1A. Pin 1 of the operational amplifier U1A is connected to one end of resistor R7, and the other end of resistor R7 is connected to the two gates G1 and G2 of the field effect transistor MOSFET1 in the H-bridge. The resistance values ​​of resistors R3 and R4 are 10kΩ, and the resistance value of resistor R7 is 100Ω.

[0026] Furthermore, pin 8 of the second operational amplifier U1B is connected to +5V, pin 4 is connected to -5V, one end of resistor R6 is connected to the error voltage port VB, and the other end of resistor R6 is connected to pin 6 of the first operational amplifier U1B. One end of resistor R5 is connected to ground, and the other end of resistor R5 is connected to pin 5 of the first operational amplifier U1B. Pin 7 of the operational amplifier U1B is connected to one end of resistor R8, and the other end of resistor R8 is connected to the two gates G1 and G2 of the field effect transistor MOSFET2 in the H-bridge. The resistance values ​​of resistors R5 and R6 are 10kΩ, and the resistance value of resistor R8 is 100Ω.

[0027] Furthermore, pin 1 of MOSFET1 is grounded, pin 2 of MOSFET1 is first shorted to pin 5 of MOSFET1 and then connected to one end of resistor R7 in the first comparator, pin 3 of MOSFET1 is shorted to pin 6 of MOSFET2 and then connected to pin 1 of thermoelectric cooler U4, pin 4 of MOSFET1 is connected to the voltage output port VT of output voltage adjustable DC-DC chip U5, pin 1 of MOSFET2 is grounded, pin 2 of MOSFET2 is first shorted to pin 5 of MOSFET2 and then connected to one end of resistor R8 in the second comparator, pin 3 of MOSFET2 is shorted to pin 6 of MOSFET2 and then connected to pin 2 of thermoelectric cooler U4, pin 4 of MOSFET2 is connected to the voltage output port VT of output voltage adjustable DC-DC chip U5.

[0028] Furthermore, pin 8 of the third operational amplifier U2A is connected to +5V and pin 4 is grounded. Pin 1 of the third operational amplifier U2A is shorted to pin 2 of U2A and then connected to one end of resistor R11 in the adder. The resistance of resistor R12 is 1kΩ.

[0029] Furthermore, pin 8 of the fourth operational amplifier U2B is connected to +5V, and pin 4 is grounded. One end of resistors R14 and R17 are connected in parallel, and the parallel end is connected to pin 6 of the fourth operational amplifier. The other end of resistor R14 is connected to pin 7 of the fourth operational amplifier, and also to one end of resistor R13 in the adder. One end of resistor R16 is connected to the thermistor error voltage port VB, and the other end is connected to resistor R17. The other end of resistor R17 is connected to pin 6 of the fourth operational amplifier. One end of resistor R18 is connected to ground, and the other end is connected to pin 5 of the fourth operational amplifier. The resistance of resistor R14 is 100kΩ, the resistance of resistor R16 is 1kΩ, the resistance of resistor R17 is 100kΩ, and the resistance of resistor R18 is 10kΩ.

[0030] Furthermore, pin 8 of the fifth operational amplifier U3A is connected to +5V, and pin 4 is connected to -5V. One end of resistor R9 is connected in parallel with one end of resistors R10, R11, and R13, and the parallel end is then connected to pin 2 of the fifth operational amplifier U3A. The other end of resistor R9 is connected to the fifth operational amplifier U3A and simultaneously to one end of resistor R2 in the DC-DC adjustable power supply. The other end of resistor R10 is connected to a -1.2V DC power supply. The other end of resistor R11 is connected to pin 1 of the voltage follower third operational amplifier U2A. The other end of resistor R13 is connected to pin 7 of the fourth operational amplifier U2B in the inverting proportional amplifier. One end of R15 is connected to ground, and the other end of R15 is connected to pin 3 of the fifth operational amplifier U3A in the adder. The resistance values ​​of resistors R9, R10, R11, and R13 are 100kΩ, and the resistance value of resistor R15 is 10kΩ.

[0031] In this embodiment, existing chips require new chip development for special applications (e.g., drive current greater than 4A), which is too costly. Furthermore, these power supply chips operate on low-voltage DC power with a maximum voltage of 5.5V, necessitating secondary voltage regulation in high-voltage DC power supply systems to ensure normal chip operation. This additional regulation inevitably leads to reduced power efficiency.

[0032] In high DC voltage power supply equipment, such as 12V or 24V DC power supply, a single-stage DC-DC drive can be used to drive the TEC. If a dedicated chip is used, such as the dedicated chip ADN8834 or ADN8835, the voltage needs to be stepped down to 5V using a single-stage DC-DC chip before the TEC is driven by the ADN8834. Therefore, the total efficiency is equal to the product of the efficiencies of the two chips. If the drive device of this invention is used, for example, using the Jiangsu Zhanxin XC8224 chip, the input voltage is 5V to 36V. Therefore, the DC-DC chip can be used directly to drive it, and the total efficiency is equal to the efficiency of a single DC-DC chip, which is significantly higher than the total efficiency of using a dedicated chip.

[0033] For example, using dedicated chips ADN8834 and ADN8835, the current is 1.5A and 3A respectively; if a direct DC-DC drive is used, taking Jiangsu Zhanxin XC8224 as an example, its drive current can reach 8A.

[0034] Composed of a DC-DC chip, operational amplifier, and MOSFET, when there are special requirements for drive voltage and current, the DC-DC chip can be selected according to the specific requirements, without the need to redesign a dedicated chip, thus solving the problem of needing to develop a new chip.

[0035] Please see Figure 2 Secondly, a laser TEC driving method for driving and controlling the laser TEC as described in the first aspect includes the following steps:

[0036] Device S1 receives the error voltage control signal VB.

[0037] S2, the first comparator and the second comparator, compare the voltage VB, which can be divided into two cases: greater than 0V and less than 0V.

[0038] When VB is greater than 0V, the analysis is as follows:

[0039] The first comparator IN+ outputs +5V, and the second comparator IN- outputs -5V. At this time, the gates G1 and G2 of the N-type field-effect transistor of MOSFET1 are +5V, that is, the N-type transistor is turned on and the P-type transistor is turned off. The gates G1 and G2 of the N-type field-effect transistor of MOSFET2 are -5V, that is, the N-type transistor is turned off and the P-type transistor is turned on. The current flows sequentially through the VT of the DC-DC chip, the P-type field-effect transistor of MOSFET2, terminal 2 of the laser cooler TEC, terminal 1 of the laser cooler TEC, and the N-type field-effect transistor of MOSFET1 to the ground GND terminal, forming a loop.

[0040] The voltage follower output voltage equals VBP, which equals VB. Since pin 4 of the fourth operational amplifier is grounded (0V), the voltage inverter output voltage VBN equals 0V. Based on the operating principle of an adder based on an operational amplifier, the adder output voltage is:

[0041] VH=-(-1.2+VBP+VBN)=1.2-VBP (1)

[0042] Taking the Jiangsu Zhanxin XC8224 chip as an example, utilizing the adjustable output voltage characteristic of the adjustable DC-DC power supply chip, the core of the voltage adjustment in the above formula lies in the fact that the DC-DC chip can automatically adjust the voltage to ensure that the voltage feedback pin FB remains constant at 0.6V. Therefore, the voltage VFB at the DC-DC chip's voltage feedback pin is:

[0043] VFB = VH + R2(VT - VH) / (R1 + R2)

[0044] The resistance of R1 and R2 is 10kΩ.

[0045] That is, 0.6 = VH + (VT - VH) / 2

[0046] Substituting equation (1) into the above equation, we can obtain...

[0047] 0.6 = 1.2 - VBP + (VT - 1.2 + VBP) / 2

[0048] Organized

[0049] VBP - 0.6 = (VT - 1.2 + VBP) / 2

[0050] Organized

[0051] VT = VBP

[0052] Since VBP = VB, the above formula can be obtained.

[0053] VT = VB

[0054] The analysis is as follows when VB is less than 0V:

[0055] The first comparator IN+ outputs -5V, and the second comparator IN- outputs +5V. At this time, the gates G1 and G2 of the N-type field-effect transistor of MOSFET1 are -5V, that is, the N-type transistor is cut off and the P-type transistor is turned on. The gates G1 and G2 of the N-type field-effect transistor of MOSFET2 are +5V, that is, the N-type transistor is turned on and the P-type transistor is cut off. The current flows sequentially through the VT of the DC-DC chip, the P-type field-effect transistor of MOSFET1, terminal 1 of the laser cooler TEC, terminal 2 of the laser cooler TEC, and the N-type field-effect transistor of MOSFET2 to the ground GND terminal, forming a loop.

[0056] Since pin 4 of the third operational amplifier is ground (0V), the voltage follower output voltage VBP equals 0V, and the voltage inverter output voltage VBN equals -VB. Based on the operating principle of an adder based on an operational amplifier, the adder output voltage is:

[0057] VH=-(-1.2+VBP+VBN)=1.2-VBN (2)

[0058] Since VBN = -VB, the above formula can be obtained.

[0059] VH = 1.2 + VB

[0060] Taking the Jiangsu Zhanxin XC8224 chip as an example, utilizing the adjustable output voltage characteristic of the adjustable DC-DC power supply chip, the core of the voltage adjustment in the above formula lies in the fact that the DC-DC chip can automatically adjust the voltage to ensure that the voltage feedback pin FB remains constant at 0.6V. Therefore, the voltage feedback pin VFB is:

[0061] VFB = VH + R2(VT - VH) / (R1 + R2)

[0062] The resistance of R1 and R2 is 10kΩ.

[0063] That is, 0.6 = VH + (VT - VH) / 2

[0064] Substituting equation (2) into the above equation, we get...

[0065] 0.6 = 1.2 - VBN + (VT - 1.2 + VBN) / 2

[0066] Organized

[0067] VBN-0.6=(VT-1.2+VBN) / 2

[0068] Organized

[0069] VT = VBN

[0070] Since VBN = -VB, the above formula can be obtained.

[0071] VT = -VB

[0072] When VB > 0, the current direction of the laser cooler flows from pin 2 to pin 1, and the current magnitude is determined by the value of VB, approximately equal to VB divided by the internal resistance of the TEC. When VB < 0, the current direction of the laser cooler flows from pin 1 to pin 2, and the current magnitude is determined by the value of VB, approximately equal to VB divided by the internal resistance of the TEC.

[0073] The S3 laser is designed so that when the current flows from pin 2 to pin 1, it is for cooling, and when the current flows from pin 1 to pin 2, it is for heating. Changing the polarity of the VB voltage can switch the laser between cooling and heating, and changing the magnitude of the VB voltage can change the intensity of cooling (heating), thereby changing the working stability of the internal chip of the laser and realizing the laser's TEC drive and control functions.

[0074] Specifically, the device receives the error voltage control signal VB. The first comparator and the second comparator compare the voltage VB. When VB > 0, the laser cooler current flows from pin 2 to pin 1, and the current magnitude is determined by the value of VB, approximately equal to VB divided by the TEC internal resistance. When VB < 0, the laser cooler current flows from pin 1 to pin 2, and the current magnitude is determined by the value of VB, approximately equal to VB divided by the TEC internal resistance. The laser is designed so that when the current flows from pin 2 to pin 1, it is cooling, and when the current flows from pin 1 to pin 2, it is heating. Changing the polarity of the VB voltage can switch the laser between cooling and heating, and changing the value of the VB voltage can change the intensity of cooling (heating), thereby changing the working stability of the internal chip of the laser, thus realizing the laser TEC driving and control function.

[0075] The above-disclosed embodiments are merely one or more preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art can understand that all or part of the processes for implementing the above embodiments and equivalent changes made in accordance with the claims of this application still fall within the scope of this application.

Claims

1. A laser TEC driving device, characterized in that: The device includes a first comparator, a second comparator, a voltage follower, an inverting proportional amplifier, an adder, an H-bridge, a laser thermoelectric cooler, and an output voltage adjustable DC-DC chip. The operational amplifier chips used in the first comparator, the second comparator, the voltage follower, the inverting proportional amplifier, and the adder are all dual rail-to-rail operational amplifiers, and each operational amplifier chip contains two sets of operational amplifiers. The H-bridge is composed of a first N / P dual-channel field-effect transistor MOSFET1 and a second N / P dual-channel field-effect transistor MOSFET2.

2. The laser TEC driving device as described in claim 1, characterized in that: The first comparator includes a first operational amplifier U1A, resistors R3, R4, and R7. Pin 8 of the first operational amplifier U1A is connected to +5V, and pin 4 is connected to -5V. One end of resistor R3 is connected to the error voltage port VB, and the other end of resistor R3 is connected to pin 3 of the first operational amplifier U1A. One end of resistor R4 is connected to ground, and the other end of resistor R4 is connected to pin 2 of the first operational amplifier U1A. Pin 1 of the operational amplifier U1A is connected to one end of resistor R7, and the other end of resistor R7 is connected to the two gates G1 and G2 of the first N / P dual field-effect transistor MOSFET1 in the H-bridge. The resistance values ​​of resistors R3 and R4 are 10kΩ, and the resistance value of resistor R7 is 100Ω.

3. The laser TEC driving device as described in claim 1, characterized in that: The second comparator includes a second operational amplifier U1B, resistors R5, R6, and R8. Pin 8 of the second operational amplifier U1B is connected to +5V, and pin 4 is connected to -5V. One end of resistor R6 is connected to the error voltage port VB, and the other end is connected to pin 6 of the first operational amplifier U1B. One end of resistor R5 is connected to ground, and the other end is connected to pin 5 of the first operational amplifier U1B. Pin 7 of the operational amplifier U1B is connected to one end of resistor R8, and the other end of resistor R8 is connected to the two gates G1 and G2 of the second N / P dual-channel field-effect transistor MOSFET2 in the H-bridge. The resistance values ​​of resistors R5 and R6 are 10kΩ, and the resistance value of resistor R8 is 100Ω.

4. The laser TEC driving device as described in claim 1, characterized in that: The H-bridge includes a first N / P dual-channel field-effect transistor (MOSFET1), a second N / P dual-channel field-effect transistor (MOSFET2), and a laser thermoelectric cooler (TECU4). Pin 1 of the first N / P dual-channel field-effect transistor (MOSFET1) is grounded. Pin 2 of the first N / P dual-channel field-effect transistor (MOSFET1) is first shorted to pin 5 of the first N / P dual-channel field-effect transistor (MOSFET1) and then connected to one end of resistor R7 in the first comparator. Pin 3 of the first N / P dual-channel field-effect transistor (MOSFET1) is shorted to pin 6 of the second N / P dual-channel field-effect transistor (MOSFET2) and then connected to pin 1 of the thermoelectric cooler (TECU4). The first N / P dual-channel field-effect transistor (MOSFET1)... Pin 4 of ET1 is connected to the voltage output port VT of the adjustable DC-DC chip U5. Pin 1 of the second N / P dual-channel MOSFET2 is grounded. Pin 2 of the second N / P dual-channel MOSFET2 is first shorted to pin 5 of MOSFET2, and then connected to one end of resistor R8 in the second comparator. Pin 3 of the second N / P dual-channel MOSFET2 is shorted to pin 6 of the second N / P dual-channel MOSFET2, and then connected to pin 2 of thermoelectric cooler U4. Pin 4 of the second N / P dual-channel MOSFET2 is connected to the voltage output port VT of the adjustable DC-DC chip U5.

5. The laser TEC driving device as described in claim 1, characterized in that: The voltage follower includes a third operational amplifier U2A and a resistor R12. Pin 8 of the third operational amplifier U2A is connected to +5V and pin 4 is grounded. Pin 1 and pin 2 of the third operational amplifier U2A are shorted together and then connected to one end of resistor R11 in the adder. The resistance of resistor R12 is 1kΩ.

6. The laser TEC driving device as described in claim 1, characterized in that: The inverting proportional amplifier includes a fourth operational amplifier U2B, resistors R14, R16, R17, and R18. Pin 8 of the fourth operational amplifier U2B is connected to +5V, and pin 4 is grounded. Resistors R14 and R17 are connected in parallel at one end, and this parallel connection is also connected to pin 6 of the fourth operational amplifier U2B. The other end of resistor R14 is connected to pin 7 of the fourth operational amplifier U2B, and also to one end of resistor R13 in the adder. One end of resistor R16 is connected to the thermistor error voltage port VB, and the other end is connected to resistor R17. The other end of resistor R17 is connected to pin 6 of the fourth operational amplifier U2B. One end of resistor R18 is connected to ground, and the other end is connected to pin 5 of the fourth operational amplifier U2B. The resistance values ​​of resistors R14, R16, R17, and R18 are all 100kΩ, 1kΩ, and 1kΩ respectively.

7. The laser TEC driving device as described in claim 1, characterized in that: The adder includes a fifth operational amplifier U3A, resistors R9, R10, R11, R13, and R15. Pin 8 of the fifth operational amplifier U3A is connected to +5V, and pin 4 is connected to -5V. One end of resistor R9 is connected in parallel with one end of resistors R10, R11, and R13, and this parallel connection is then connected to pin 2 of the fifth operational amplifier U3A. The other end of resistor R9 is connected to the fifth operational amplifier U3A and simultaneously connected to one end of resistor R2 in the DC-DC adjustable power supply. The other end of resistor R10 is connected to a -1.2V DC power supply. The other end of resistor R11 is connected to pin 1 of the third operational amplifier U2A in the voltage follower. The other end of resistor R13 is connected to pin 7 of the fourth operational amplifier U2B in the inverting proportional amplifier. One end of R15 is connected to ground, and the other end of R15 is connected to pin 3 of the fifth operational amplifier U3A in the adder. The resistance values ​​of resistors R9, R10, R11, and R13 are 100kΩ, and the resistance value of resistor R15 is 10kΩ.

8. A laser TEC driving method, used in the laser TEC driving device according to any one of claims 1-7, characterized in that, Includes the following steps: The device receives the error voltage control signal VB. The first comparator and the second comparator compare the voltage VB. VB can be divided into two cases: greater than 0V and less than 0V. When VB > 0, the current direction of the laser cooler is from pin 2 to pin 1, and the magnitude of the current is determined by the value of VB. When VB < 0, the current direction of the laser cooler flows from pin 1 to pin 2, and the magnitude of the current is determined by the value of VB. The laser is designed so that when the current flows from pin 2 to pin 1, it is for cooling, and when the current flows from pin 1 to pin 2, it is for heating. Changing the polarity of the VB voltage can switch the laser between cooling and heating, and changing the magnitude of the VB voltage can change the cooling intensity.

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