TEC temperature control circuit
By combining CNC constant voltage source module and multi-stage adjustment module in the TEC temperature control circuit, the resistance value is adjusted by using digital potentiometers and analog switches or multiplexers, the power and cost deficiency in the existing technology is solved and high efficiency is achieved Temperature control, suitable for high power TEC models.
Patent Information
- Application Number
- CN202421009577.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-10
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2034-05-10
AI Technical Summary
The existing TEC temperature control circuit is difficult to balance between high power and low cost. The constant current driving chip has limited power and expensive power, while the constant voltage driving method has limited output voltage adjustment, which cannot meet the needs of high noise suppression and high refrigeration temperature.
A TEC temperature control circuit was designed, using a CNC constant voltage source module and a multi-stage adjustment module to adjust the resistance value through a digital potentiometer and an analog switch or multiplexer to achieve flexible adjustment of the output voltage and adapt to different power requirements. .
It provides a strong and stable TEC temperature control circuit that can adapt to different power requirements, expands the output voltage adjustment range and accuracy, and is suitable for high-power TEC models, improving the accuracy and application value of temperature control.
Smart Images
Figure CN222189761U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of temperature control, in particular to a TEC temperature control circuit. Background Art
[0002] The dark current noise of the CCD detector is related to temperature, and needs to be cooled by semiconductors (TEC). There are usually two ways to drive TEC, constant voltage drive and constant current drive. The constant current drive method has a better effect, and there are dedicated integrated chips for general use, such as max1978, AND8344 and other integrated chips. However, the driving power of the TEC constant current dedicated chip cannot be too large, usually within a few W to 20 W, and the chip price is relatively expensive, and the adjustment method requires external DAC to control.
[0003] The constant voltage driving method is relatively simple and low-cost. The output voltage adjustment of the DCDC chip is usually adjusted through the feedback pin FB and the external series resistor. The voltage of the FB pin of a type of DCDC chip is adjustable, and the voltage of the FB pin of most DCDC chips is fixed. The output voltage of the DCDC chip with an adjustable FB pin is usually relatively low, less than 5.5V, and the power is also relatively low. For example, TI's TPS63020. It is not suitable for some TEC models with higher voltage / power. In order to suppress the noise level, the cooling temperature of the CCD chip usually needs to be reduced to -40℃, or even -70℃, or lower, which requires a relatively high cooling power for the TEC. Therefore, it is urgent to provide a TEC control circuit that can be flexibly applied to different power requirements. Utility Model Content
[0004] In order to solve the deficiencies existing in the above-mentioned prior art, the utility model provides a TEC temperature control circuit, comprising: a digitally controlled constant voltage source module, a first adjustment module, a second adjustment module and a TEC connector; the output end of the digitally controlled constant voltage source module is respectively connected to the input end of the first adjustment module and the input end of the TEC connector, and the output end of the first adjustment module and the output end of the second adjustment module are connected to the input end of the digitally controlled constant voltage source module; the second adjustment module is a digital potentiometer, which is used to adjust the output voltage of the digitally controlled constant voltage source module to the TEC connector by controlling the resistance values of the first adjustment module and the second adjustment module.
[0005] Furthermore, the digitally controlled constant voltage source module uses a DCDC chip.
[0006] Furthermore, the first adjustment module is a first resistor with a fixed resistance.
[0007] Furthermore, the resistance of the first resistor is 147KΩ.
[0008] Furthermore, pin 2 of the DCDC chip is connected to the input voltage; pin 1 and pin 8 of the DCDC chip are connected to the input end of the first resistor and the input end of the TEC connector; the output end of the first resistor and pin 1 and pin 3 of the digital potentiometer are simultaneously connected to pin 5 of the DCDC chip.
[0009] Furthermore, the TEC temperature control circuit also includes a third adjustment module and a fourth adjustment module; the input end of the third adjustment module is connected to the output end of the first adjustment module; the output end of the fourth adjustment module is connected to the input end of the second adjustment module; the output end of the second adjustment module and the output end of the third adjustment module are connected to the input end of the digital control constant voltage source module, and the output voltage of the digital control constant voltage source module is adjusted by adjusting the resistance values of the first adjustment module, the second adjustment module, the third adjustment module and the fourth adjustment module.
[0010] Furthermore, the third adjustment module is an analog switch or a multiplexer.
[0011] Furthermore, the fourth adjustment module is an analog switch or a multiplexer.
[0012] Further, pin 2 of the DCDC chip is connected to the input voltage; pin 8 of the DCDC chip is connected to the input end of the first resistor and the input end of the TEC connector; the output end of the first resistor is connected to pins 4, 5, 6 and 7 of the third adjustment module; pins 4, 5, 6 and 7 of the fourth adjustment module are connected to pin 2 of the digital potentiometer;
[0013] Pins 1 and 3 of the digital potentiometer and pin 5 of the third adjustment module are connected to pin 5 of the DCDC chip.
[0014] Based on the above, compared with the prior art, the utility model provides a highly stable TEC temperature control circuit, which adjusts the output voltage by adjusting the numerically controlled constant voltage source module through the resistance feedback of the first adjustment module and the second adjustment module, and the second adjustment module uses a digital potentiometer, which can be subdivided into multiple gears for adjustment, and can adapt to the different power requirements of TEC, and has good application value.
[0015] Other features and beneficial effects of the utility model will be described in the subsequent description, and partly become apparent from the description, or understood by practicing the utility model. The purpose and other beneficial effects of the utility model can be achieved and obtained by the structures specifically pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. The positional relationships described in the drawings in the following description are based on the directions of the components shown in the diagrams unless otherwise specified.
[0017] Figure 1 A circuit schematic diagram of a TEC temperature control circuit provided in Embodiment 1 of the present utility model;
[0018] Figure 2 This is a circuit schematic diagram of the TEC temperature control circuit provided in the second embodiment of the present utility model.
[0019] Reference numerals:
[0020] 10. Digital control constant voltage source module 20, first adjustment module 30, second adjustment module
[0021] 40, TEC connector 50, third adjustment module 60, fourth adjustment module DETAILED DESCRIPTION
[0022] In order to make the purpose, technical solutions and advantages of the embodiments of the utility model clearer, the technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all of the embodiments; the technical features designed in different implementation modes of the utility model described below can be combined with each other as long as they do not conflict with each other; based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.
[0023] In the description of the present invention, it should be noted that all terms (including technical terms and scientific terms) used in the present invention have the same meanings as those generally understood by ordinary technicians in the field to which the present invention belongs, and cannot be understood as limitations on the present invention; it should be further understood that the terms used in the present invention should be understood to have meanings consistent with the meanings of these terms in the context of this specification and in the relevant fields, and should not be understood in an idealized or overly formal sense, unless explicitly defined in this utility model.
[0024] Embodiment 1
[0025] The utility model provides a TEC temperature control circuit, comprising: a digital control constant voltage source module 10, a first adjustment module 20, a second adjustment module 30 and a TEC connector 40; the output end of the digital control constant voltage source module 10 is respectively connected to the input end of the first adjustment module 20 and the input end of the TEC connector 40, and the output end of the first adjustment module 20 and the output end of the second adjustment module 30 are connected to the input end of the digital control constant voltage source module 10; the second adjustment module 30 is a digital potentiometer, and the output voltage output from the digital control constant voltage source module 10 to the TEC connector 40 is adjusted by controlling the resistance values of the first adjustment module 20 and the second adjustment module 30.
[0026] The digital control constant voltage source module 10 uses a DCDC chip, and through constant voltage driving, the voltage of its FB pin can be adjusted, and the model is: TPS54560DDA. The model of the digital potentiometer of the second adjustment module 30 is: TPL0102-100PWR. The first adjustment module 20 is a first resistor with a fixed resistance. Preferably, the resistance of the first resistor is 147KΩ.
[0027] like Figure 1 As shown, pin 2 of the DCDC chip is connected to the input voltage; pin 1 and pin 8 of the DCDC chip are connected to the input end of the first resistor and the input end of the TEC connector 40; the output end of the first resistor and pin 1 and pin 3 of the digital potentiometer are simultaneously connected to pin 5 of the DCDC chip.
[0028] The calculation formula of the digital control constant voltage source module 10 is:
[0029] V out =(RH / RL+1)*0.8 (1)
[0030] Where RH is the first resistor, RL is the resistance value adjusted by the digital potentiometer, V out is the output voltage of the digital controlled constant voltage source module 10.
[0031] Specific working principle: The output end of the DCDC chip is connected to the first resistor with a resistance of 147KΩ, and the resistance of the digital potentiometer is adjusted at the same time. The digital potentiometer and the first resistor are connected to the FB pin of the DCDC chip at the same time for feedback adjustment, thereby controlling the voltage output by the DCDC chip. Specifically, a BUCK DCDC chip is selected, and the calculation formula for the output voltage is as shown in the above formula (1). RH uses a fixed resistance resistor, such as 147KΩ, and RL uses a digital potentiometer. The maximum range of the digital potentiometer is generally 0~100KΩ, which is subdivided into 256 gears. The output voltage range is adjustable from 2 to 8V. By adjusting the resistance of the digital potentiometer, the output voltage of the TEC is adjusted. The 100K resistance adjustment range should correspond to the 6V adjustment range, as shown in Table 1 below.
[0032] Table 1
[0033]
[0034] Embodiment 2
[0035] Although the first embodiment can improve the accuracy of the output voltage, its adjustment range is small. This embodiment further improves the first embodiment, expands the adjustment range, and further improves the control accuracy. Specifically:
[0036] The utility model provides a TEC temperature control circuit, which further includes a third adjustment module 50 and a fourth adjustment module 60 on the basis of the first embodiment; the input end of the third adjustment module 50 is connected to the output end of the first adjustment module 20; the output end of the fourth adjustment module 60 is connected to the input end of the second adjustment module 30; the output end of the second adjustment module 30 and the output end of the third adjustment module 50 are connected to the input end of the digital control constant voltage source module 10, and the output voltage of the digital control constant voltage source module 10 is adjusted by adjusting the resistance values of the first adjustment module 20, the second adjustment module 30, the third adjustment module 50 and the fourth adjustment module 60.
[0037] Preferably, the third adjustment module 50 and the fourth adjustment module 60 are analog switches or multiplexers. Figure 2 As shown, pin 2 of the DCDC chip is connected to the input voltage; pin 8 of the DCDC chip is connected to the input end of the first resistor and the input end of the TEC connector 40; the output end of the first resistor is connected to pins 4, 5, 6 and 7 of the third adjustment module 50; pins 4, 5, 6 and 7 of the fourth adjustment module 60 are connected to pin 2 of the digital potentiometer; pins 1 and 3 of the digital potentiometer and pin 5 of the third adjustment module 50 are connected to pin 5 of the DCDC chip.
[0038] like Figure 2 As shown, the third adjustment module 50 has four gears to choose from, the first gear is connected to the resistor R6, the resistance is 0Ω; the second gear is connected to the resistor R7, the resistance is 150KΩ; the second gear is connected to the resistor R8, the resistance is 400KΩ; the second gear is connected to the resistor R9, the resistance is 680KΩ. It can be accumulated and output with the resistance of the first adjustment module 20.
[0039] The fourth adjustment module 60 has four gears to choose from, the first gear is connected to the resistor R10, the resistance is 50KΩ; the second gear is connected to the resistor R11, the resistance is 25KΩ; the third gear is connected to the resistor R12, the resistance is 20KΩ; the third gear is connected to the resistor R13, the resistance is 15KΩ. It can be accumulated and output with the resistance of the second adjustment module 30.
[0040] In specific implementation, by adding the third adjustment module 50 and the fourth adjustment module 60, two selectable resistors RX1 and RX2 are added, and the first adjustment module 20 and the third adjustment module 50 are combined into a whole, thereby expanding the resistance adjustment range. The fourth adjustment module 60 increases the resistance adjustment range of the second adjustment module 30, that is, the digital potentiometer, and further subdivides the adjustment range of the output voltage.
[0041] Specifically, the calculation formula of the digital control constant voltage source module 10 is:
[0042] V out =((RH+RX1) / (RL+RX2)+1)*0.8 (2)
[0043] Where RH is the first resistor, RL is the resistance value adjusted by the digital potentiometer, RX1 is the resistance value obtained by the analog switch, RX2 is the resistance value obtained by the multiplexer, V out is the output voltage of the digital controlled constant voltage source module 10.
[0044] Taking Table 2 as an example, the voltage of 2 to 8 V is subdivided into 4 segments. The output voltage change corresponding to the resistance adjustment of the digital potentiometer becomes smaller, which can improve the accuracy of output voltage adjustment.
[0045] Table 2
[0046]
[0047]
[0048] Preferably, the circuit method of this proposal can adapt to TEC models with different voltage ranges, and can be adjusted in sections according to different voltage specifications. The number of sections can be designed according to actual needs. For example, the maximum voltage of TEC is 7.6V, and it is designed according to 80% of the driving voltage, which is about 6V driving voltage.
[0049] In order to improve the accuracy of temperature control, PID control algorithm is generally introduced to dynamically adjust the output resistance of the array potentiometer to achieve dynamic adjustment of the output voltage amplitude. Through segmented design, the output voltage is limited to around 6V, such as 6±1V, so that the digital potentiometer 0~100K corresponds to an output voltage of 5~7V, which can improve the accuracy of PID temperature control.
[0050] In this way, there is no restriction on the selection of DCDC chips, the selection range is wider, and the applicability is wider. It is not limited to BUCK DCDC chips, as long as the output voltage is regulated by the feedback pin and the output voltage can be adjusted by the external series resistor, any DCDC chip can be used.
[0051] Table 3 TEC performance parameters
[0052]
[0053] In addition, those skilled in the art should understand that, although there are many problems in the prior art, each embodiment or technical solution of the utility model can be improved in only one or several aspects, without having to solve all the technical problems listed in the prior art or background technology at the same time. Those skilled in the art should understand that the content not mentioned in a claim should not be used as a limitation on the claim.
[0054] Although the terminology such as digital control constant voltage source module, first adjustment module, second adjustment module, third adjustment module and fourth adjustment module is used more frequently in this article, the possibility of using other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the utility model; interpreting them as any additional restrictions is contrary to the spirit of the utility model; the terms "first", "second", etc. (if any) in the description and claims of the embodiment of the utility model and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.
[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the utility model.
Claims
1. A TEC temperature control circuit, characterized in that: include: A digital control constant voltage source module, a first adjustment module, a second adjustment module and a TEC connector; The output end of the digital control constant voltage source module is connected to the input end of the first adjustment module and the input end of the TEC connector respectively, and the output end of the first adjustment module and the output end of the second adjustment module are connected to the input end of the digital control constant voltage source module; The second adjustment module is a digital potentiometer, which is used to adjust the output voltage output by the digital control constant voltage source module to the TEC connector by controlling the resistance values of the first adjustment module and the second adjustment module.
2. The TEC temperature control circuit according to claim 1, characterized in that: The digital controlled constant voltage source module uses a DCDC chip.
3. The TEC temperature control circuit according to claim 2, characterized in that: The first adjustment module is a first resistor with a fixed resistance.
4. The TEC temperature control circuit according to claim 3, characterized in that: The resistance of the first resistor is 147KΩ.
5. The TEC temperature control circuit according to claim 3, characterized in that: Pin 2 of the DCDC chip is connected to the input voltage; Pin 1 and Pin 8 of the DCDC chip are connected to the input end of the first resistor and the input end of the TEC connector; the output end of the first resistor and Pin 1 and Pin 3 of the digital potentiometer are simultaneously connected to Pin 5 of the DCDC chip.
6. The TEC temperature control circuit according to claim 3, characterized in that: The TEC temperature control circuit also includes a third adjustment module and a fourth adjustment module; The input end of the third adjustment module is connected to the output end of the first adjustment module; the output end of the fourth adjustment module is connected to the input end of the second adjustment module; the output end of the second adjustment module and the output end of the third adjustment module are connected to the input end of the digital control constant voltage source module, and the output voltage of the digital control constant voltage source module is adjusted by adjusting the resistance values of the first adjustment module, the second adjustment module, the third adjustment module and the fourth adjustment module.
7. The TEC temperature control circuit according to claim 6, characterized in that: The third adjustment module is an analog switch or a multiplexer.
8. The TEC temperature control circuit according to claim 6, characterized in that: The fourth adjustment module is an analog switch or a multiplexer.
9. The TEC temperature control circuit according to claim 6, characterized in that: Pin 2 of the DCDC chip is connected to the input voltage; Pin 8 of the DCDC chip is connected to the input end of the first resistor and the input end of the TEC connector; the output end of the first resistor is connected to Pin 4, Pin 5, Pin 6 and Pin 7 of the third adjustment module; Pin 4, Pin 5, Pin 6 and Pin 7 of the fourth adjustment module are connected to Pin 2 of the digital potentiometer; Pins 1 and 3 of the digital potentiometer and pin 5 of the third adjustment module are connected to pin 5 of the DCDC chip.