Temperature detection circuit and power supply

Abstract

The present application is applicable to the field of electronic circuit technology, and provides a temperature detection circuit and power supply. The temperature detection circuit includes a first current source, a second current source, a first switch unit, a temperature acquisition unit, and a first logic unit. During temperature detection, when the temperature of the object to be measured changes, the resistance of the temperature acquisition unit changes accordingly, and the acquisition voltage output by the temperature acquisition unit also changes. When the resistance of the temperature acquisition unit is greater than a preset value, the first logic unit controls the first switch unit to disconnect, and only the first current source provides current to the temperature acquisition unit. The operating current of the temperature acquisition unit is the first operating current, which prevents the temperature acquisition unit from outputting an excessively large acquisition voltage due to excessive resistance, and ensures that the acquisition voltage output by the temperature acquisition unit is within a preset range. No additional voltage source is required when performing voltage comparison analysis, thereby reducing the power consumption and production cost of the system.

Description

Technical Field

[0001] The present application belongs to the field of electronic circuit technology, and in particular relates to a temperature detection circuit and a power supply. Background Art

[0002] A thermistor is a temperature-sensitive resistor whose resistance changes with temperature. Therefore, thermistors are often used in temperature detection circuits. During temperature acquisition, a preset current is supplied to the thermistor. As the thermistor's resistance changes, the voltage output by the temperature detection circuit also changes, thereby enabling temperature acquisition.

[0003] The signal processing circuit compares the voltage output by the temperature detection circuit with multiple preset reference voltages and outputs an indication signal indicating the current temperature. When the temperature detection circuit captures a wide range of temperatures, the voltage output by the temperature detection circuit also ranges widely, necessitating the need for multiple, widely varying, preset reference voltages. A system can typically only provide preset reference voltages within a certain voltage range. If the multiple preset reference voltages differ significantly, additional voltage sources are required, leading to increased system power consumption and higher costs. Summary of the Invention

[0004] The embodiments of the present application provide a temperature detection circuit and a power supply, which can solve the problem that when the temperature range collected by the temperature detection circuit is too large, the voltage range output by the temperature detection circuit is large.

[0005] In a first aspect, an embodiment of the present application provides a temperature detection circuit, including a first current source, a second current source, a first switching unit, a temperature acquisition unit, and a first logic unit, wherein the first current source is electrically connected to the temperature acquisition unit, the second current source is electrically connected to the temperature acquisition unit via the first switching unit, and the first logic unit is electrically connected to the temperature acquisition unit and the first switching unit, respectively;

[0006] The first current source is used to provide a first current to the temperature acquisition unit; the second current source is used to provide a second current to the temperature acquisition unit; the temperature acquisition unit is used to output an acquisition voltage according to the temperature of the object to be measured; the first logic unit is used to output an indication signal for indicating the temperature information of the object to be measured according to the acquisition voltage; the first logic unit is also used to control the first switch unit to be turned on or off according to the acquisition voltage, so that the acquisition voltage is within a preset range.

[0007] In a possible implementation of the first aspect, the first logic unit includes a first comparing unit, a second comparing unit, a third comparing unit, a reference voltage unit, and an arithmetic unit, the first comparing unit being electrically connected to the temperature acquisition unit, the reference voltage unit, and the arithmetic unit, respectively; the second comparing unit being electrically connected to the temperature acquisition unit and the arithmetic unit, respectively; the third comparing unit being electrically connected to the temperature acquisition unit and the arithmetic unit, respectively; and the arithmetic unit being electrically connected to the reference voltage unit and the first switching unit, respectively.

[0008] The first comparison unit is used to output a first comparison signal based on a reference voltage and the collected voltage; the second comparison unit is used to output a second comparison signal based on a third preset voltage and the collected voltage; the third comparison unit is used to output a third comparison signal based on a fourth preset voltage and the collected voltage; the operation unit is used to output a first control signal and a second control signal with opposite levels based on the first comparison signal, the first control signal and the first comparison signal have the same level, and the first control signal is used to control the first switch unit to be turned on or off; the operation unit is also used to output an indication signal for indicating the temperature information of the object to be measured based on the first comparison signal, the second comparison signal and the third comparison signal; the reference voltage unit is used to output the reference voltage based on the first control signal and the second control signal, and the reference voltage is the first preset voltage or the second preset voltage.

[0009] In a possible implementation of the first aspect, the first comparison unit includes a first comparator, a positive input end of the first comparator is electrically connected to the temperature acquisition unit, a reverse input end of the first comparator is electrically connected to the reference voltage unit, and an output end of the first comparator is electrically connected to the operation unit.

[0010] In a possible implementation of the first aspect, the second comparison unit includes a second comparator, a positive input terminal of the second comparator is electrically connected to a third voltage source for providing the third preset voltage, a reverse input terminal of the second comparator is electrically connected to the temperature acquisition unit, and an output terminal of the third comparator is electrically connected to the operation unit.

[0011] In a possible implementation of the first aspect, the third comparison unit includes a third comparator, a positive input terminal of the third comparator is electrically connected to a fourth voltage source for providing the fourth preset voltage, a reverse input terminal of the third comparator is electrically connected to the temperature acquisition unit, and an output terminal of the third comparator is electrically connected to the operation unit.

[0012] In a possible implementation of the first aspect, the operation unit includes a first inverter, a second inverter, a third inverter, a first NOR gate, a second NOR gate, and a third NOR gate. The input end of the first inverter is electrically connected to the first comparison unit, the output end of the first inverter is electrically connected to the reference voltage unit, the input end of the second inverter, and the first input end of the second NOR gate, respectively. The first input end of the first NOR gate is electrically connected to the output end of the second inverter, the reference voltage unit, and the switch unit, respectively. The second input end of the first NOR gate is electrically connected to the third comparison unit, the output end of the first NOR gate is electrically connected to the first input end of the third NOR gate, the second input end of the second NOR gate is electrically connected to the second comparison unit, the output end of the second NOR gate is electrically connected to the second input end of the third NOR gate, the input end of the third inverter is electrically connected to the output end of the third NOR gate, and the output end of the third inverter is used to output the indication signal.

[0013] In a possible implementation of the first aspect, the reference voltage unit includes a first transmission gate and a second transmission gate, the first control end of the first transmission gate is electrically connected to the second control end of the second transmission gate and the output end of the first inverter, respectively, the second control end of the first transmission gate is electrically connected to the first control end of the second transmission gate, the output end of the second inverter, and the first switch unit, the input end of the first transmission gate is electrically connected to a first voltage source for providing the first preset voltage, the output end of the first transmission gate is electrically connected to the output end of the second transmission gate and the inverting input end of the first comparator, respectively, and the input end of the second transmission gate is electrically connected to a second voltage source for providing the second preset voltage.

[0014] In a possible implementation of the first aspect, the first switching unit includes a first switching tube, a gate of the first switching tube is electrically connected to the output end of the second inverter, a drain of the first switching tube is electrically connected to the second current source, and a source of the first switching tube is electrically connected to the temperature acquisition unit.

[0015] In a possible implementation of the first aspect, the temperature acquisition unit includes a first resistor and a thermistor, wherein a first end of the first resistor is electrically connected to the first current source and the source of the first switching tube, respectively; a first end of the thermistor is electrically connected to a second end of the first resistor, a positive input end of the first comparator, a negative input end of the second comparator, and a negative input end of the third comparator, respectively; and a second end of the thermistor is grounded.

[0016] In a possible implementation of the first aspect, the temperature detection circuit further includes a second switch unit, a second logic unit, and a latch unit;

[0017] The input end of the second switch unit is electrically connected to the first current source and the first switch unit respectively, the output end of the second switch unit is electrically connected to the temperature acquisition unit, the control end of the second switch unit is electrically connected to the second logic unit, the second logic unit is electrically connected to the first logic unit and the latch unit respectively, and the latch unit is electrically connected to the first logic unit;

[0018] The second logic unit is used to receive an enable signal and output a third control signal and a fourth control signal with opposite levels according to the enable signal, the third control signal and the enable signal have the same level, and the fourth control signal is used to control the second switch unit to be turned on or off; the latch unit is used to latch the indication signal according to the third control signal.

[0019] In a possible implementation of the first aspect, the second logic unit includes a fourth inverter, a fifth inverter, and a delayer, the input end of the fourth inverter is used to receive the enable signal, the output end of the fourth inverter is electrically connected to the second switch unit and the input end of the fifth inverter, respectively, the output end of the fifth inverter is electrically connected to the input end of the delayer and the first logic unit, and the output end of the delayer is electrically connected to the latch unit.

[0020] In a possible implementation of the first aspect, the latch unit includes a latch, a data input end of the latch is electrically connected to the first logic unit, a clock input end of the latch is electrically connected to the output end of the delayer, and the output end of the latch is used to output the latched indication signal.

[0021] In a second aspect, an embodiment of the present application provides a power supply comprising a battery, a controller, and the temperature detection circuit described in any one of the first aspects, wherein the temperature acquisition unit is used to acquire the temperature of the battery and output an indication signal for indicating the temperature information of the battery based on the temperature of the battery, and the controller is used to adjust the temperature of the battery according to the indication signal.

[0022] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0023] During temperature detection, when the temperature of the object to be measured changes, the resistance of the temperature acquisition unit changes accordingly, and the acquisition voltage output by the temperature acquisition unit also changes. When the resistance of the temperature acquisition unit is less than a preset value, the first logic unit controls the first switch unit to be turned on, and the first current source and the second current source simultaneously provide current to the temperature acquisition unit, and the operating current of the temperature acquisition unit is the sum of the first current and the second current. When the resistance of the temperature acquisition unit is greater than the preset value, the first logic unit controls the first switch unit to be turned off, and only the first current source provides current to the temperature acquisition unit, and the operating current of the temperature acquisition unit is the first operating current. In this way, the acquisition voltage output by the temperature acquisition unit can be prevented from being too large due to excessive resistance, so that the acquisition voltage output by the temperature acquisition unit is within a preset range. No additional voltage source is required when performing voltage comparison analysis, thereby reducing the power consumption and production cost of the system.

[0024] It can be understood that the beneficial effects of the second to fifth aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0026] Figure 1 This is a principle block diagram of a temperature detection circuit provided in one embodiment of the present application;

[0027] Figure 2 1 is a circuit connection diagram of a temperature detection circuit provided in one embodiment of the present application;

[0028] Figure 3 This is a circuit connection diagram of a temperature detection circuit provided in another embodiment of the present application. DETAILED DESCRIPTION

[0029] In the following description, specific details such as specific system structures and techniques are provided for purposes of illustration rather than limitation to facilitate a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that the present application may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid obscuring the description of the present application with unnecessary detail.

[0030] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or collections thereof.

[0031] It will also be understood that the term "and / or" used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0032] As used in this specification and the appended claims, the term "if" can be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "upon determination" or "in response to determining" or "upon detection of [described condition or event]" or "in response to detecting [described condition or event]," depending on the context.

[0033] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0034] References to "one embodiment" or "some embodiments" in this specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.

[0035] Figure 1 FIG1 shows a principle block diagram of a temperature detection circuit provided by an embodiment of the present application. Figure 1 As shown, the temperature detection circuit includes a first current source 100, a second current source 200, a first switching unit 300, a temperature acquisition unit 400 and a first logic unit 500. The first current source 100 is electrically connected to the temperature acquisition unit 400, the second current source 200 is electrically connected to the temperature acquisition unit 400 through the first switching unit 300, and the first logic unit 500 is electrically connected to the temperature acquisition unit 400 and the first switching unit 300, respectively.

[0036] Specifically, the temperature acquisition unit 400 outputs a corresponding acquisition voltage based on the temperature of the object to be measured, and transmits the acquisition voltage to the first logic unit 500. The first logic unit 500 outputs an indication signal indicating the temperature of the object to be measured based on the acquisition voltage, and transmits the indication signal to the controller. Based on the indication signal, the controller can analyze whether the current temperature of the object to be measured is within a preset temperature range. If the current temperature of the object to be measured exceeds the preset temperature range, the controller adjusts the temperature of the object to be measured by regulating the charging current or operating current of the object to be measured, so that the temperature of the object to be measured is within the preset temperature range.

[0037] When the temperature of the object to be measured changes, the resistance of the temperature acquisition unit 400 will change, and the acquisition voltage output by the temperature acquisition unit 400 will change accordingly. The temperature coefficient of the temperature acquisition unit 400 can be a positive temperature coefficient or a negative temperature coefficient.

[0038] When the temperature coefficient of the temperature acquisition unit 400 is a positive temperature coefficient, the resistance of the temperature acquisition unit 400 increases as the temperature rises. When the temperature of the object to be measured is low, the resistance of the temperature acquisition unit 400 is low, the first logic unit 500 controls the first switch unit 300 to be turned on, and the first current source 100 and the second current source 200 simultaneously supply power to the temperature acquisition unit 400. The operating current of the temperature acquisition unit 400 is the sum of the first current and the second current. When the temperature of the object to be measured is high, the resistance of the temperature acquisition unit 400 is high, the first logic unit 500 controls the first switch unit 300 to be turned off, and only the first current source 100 supplies current to the temperature acquisition unit 400. The operating current of the temperature acquisition unit 400 is the first current. When the resistance of the temperature acquisition unit 400 is large, its operating current is small; when the resistance of the temperature acquisition unit 400 is small, its operating current is large. As a result, the voltage variation range output by the temperature acquisition unit 400 can be controlled not to be too large, so that the voltage output by the temperature acquisition unit 400 is within a preset range. When performing voltage comparison analysis, there is no need to add an additional voltage source, thereby reducing the power consumption and production cost of the system.

[0039] When the temperature coefficient of the temperature acquisition unit 400 is negative, the resistance of the temperature acquisition unit 400 decreases as the temperature increases. When the temperature of the object to be measured is high, the resistance of the temperature acquisition unit 400 is low, the first logic unit 500 controls the first switch unit 300 to be turned on, and the first current source 100 and the second current source 200 simultaneously supply power to the temperature acquisition unit 400. The operating current of the temperature acquisition unit 400 is the sum of the first current and the second current. When the temperature of the object to be measured is low, the resistance of the temperature acquisition unit 400 is high, the first logic unit 500 controls the first switch unit 300 to be turned off, and only the first current source 100 supplies current to the temperature acquisition unit 400. The operating current of the temperature acquisition unit 400 is the first current. When the resistance of the temperature acquisition unit 400 is large, its operating current is small; when the resistance of the temperature acquisition unit 400 is small, its operating current is large. As a result, the voltage variation range output by the temperature acquisition unit 400 can be controlled not to be too large, so that the voltage output by the temperature acquisition unit 400 is within a preset range. When performing voltage comparison analysis, there is no need to add an additional voltage source, thereby reducing the power consumption and production cost of the system.

[0040] It should be noted that, in order to facilitate the description of the solution, the following description is given by taking the case where the temperature coefficient of the temperature acquisition unit 400 is a negative temperature coefficient as an example.

[0041] In one embodiment of the present application, Figure 2 As shown, the first logic unit 500 includes a first comparing unit 501, a second comparing unit 502, a third comparing unit 503, a reference voltage unit 504 and an operation unit 505. The first comparing unit 501 is electrically connected to the temperature acquisition unit 400, the reference voltage unit 504 and the operation unit 505, respectively. The second comparing unit 502 is electrically connected to the temperature acquisition unit 400 and the operation unit 505, respectively. The third comparing unit 503 is electrically connected to the temperature acquisition unit 400 and the operation unit 505, respectively. The operation unit 505 is electrically connected to the reference voltage unit 504 and the first switching unit 300, respectively.

[0042] Specifically, the first comparison unit 501 is configured to output a first comparison signal based on the reference voltage and the sampled voltage; the second comparison unit 502 is configured to output a second comparison signal based on the third preset voltage V3 and the sampled voltage; and the third comparison unit 503 is configured to output a third comparison signal based on the fourth preset voltage V4 and the sampled voltage. The operation unit 505 is configured to output a first control signal and a second control signal of opposite levels based on the first comparison signal. The first control signal and the first comparison signal have the same level, and the first control signal is used to control the first switch unit 300 to be on or off. The operation unit 505 is further configured to output an indication signal (NTC) indicating the temperature of the object to be measured based on the first, second, and third comparison signals. The reference voltage unit 504 is configured to output a reference voltage based on the first control signal and the second control signal. The reference voltage is either the first preset voltage V1 or the second preset voltage V2.

[0043] Because the first control signal and the first comparison signal have the same level, and the first control signal is used to control the on / off switching of the first switch unit 300, the first comparison signal output by the first comparison unit 501 can control the on / off switching of the first switch unit 300, thereby controlling the operating current of the temperature acquisition unit 400. When the temperature of the object to be measured is lower than the preset temperature, the resistance of the temperature acquisition unit 400 is higher than the preset resistance, the acquisition voltage output by the temperature acquisition unit 400 is higher than the first preset voltage V1, and the first comparator outputs the first comparison signal to control the off-state switching of the first switch unit 300. Only the first current source 100 supplies current to the temperature acquisition unit 400, reducing the operating current of the temperature acquisition unit 400 and the acquisition voltage output by the temperature acquisition unit 400. When the temperature of the object to be measured is greater than a preset temperature, the resistance of the temperature acquisition unit 400 is less than the preset resistance, and the acquisition voltage output by the temperature acquisition unit 400 is less than the first preset voltage V1. The first comparator outputs a first comparison signal to turn on the first switch unit 300. The first current source 100 and the second current source 200 simultaneously provide current to the temperature acquisition unit 400, increasing the operating current of the temperature acquisition unit 400 and the acquisition voltage output by the temperature acquisition unit 400. This controls the acquisition voltage output by the temperature acquisition unit 400 to be within a preset voltage range.

[0044] For example, Figure 2 As shown, the first comparison unit 501 includes a first comparator U1, the positive input end of the first comparator U1 is electrically connected to the temperature acquisition unit 400, the negative input end of the first comparator U1 is electrically connected to the reference voltage unit 504, and the output end of the first comparator U1 is electrically connected to the operation unit 505.

[0045] Specifically, when the collected voltage output by the temperature collection unit 400 is greater than the reference voltage, the first comparator U1 outputs a high level signal. When the collected voltage output by the temperature collection unit 400 is less than the reference voltage, the first comparator U1 outputs a low level signal.

[0046] For example, Figure 2 As shown, the second comparison unit 502 includes a second comparator U2, the positive input terminal of the second comparator U2 is electrically connected to a third voltage source for providing a third preset voltage V3, the reverse input terminal of the second comparator U2 is electrically connected to the temperature acquisition unit 400, and the output terminal of the third comparator is electrically connected to the operation unit 505.

[0047] Specifically, when the acquisition voltage output by the temperature acquisition unit 400 is greater than the third preset voltage V3, the second comparator U2 outputs a low level signal. When the acquisition voltage output by the temperature acquisition unit 400 is less than the third preset voltage V3, the second comparator U2 outputs a high level signal.

[0048] For example, Figure 2 As shown, the third comparison unit 503 includes a third comparator U3, the positive input terminal of the third comparator U3 is electrically connected to a fourth voltage source for providing a fourth preset voltage V4, the reverse input terminal of the third comparator U3 is electrically connected to the temperature acquisition unit 400, and the output terminal of the third comparator U3 is electrically connected to the operation unit 505.

[0049] Specifically, when the acquisition voltage output by the temperature acquisition unit 400 is greater than the fourth preset voltage V4, the third comparator U3 outputs a low level signal. When the acquisition voltage output by the temperature acquisition unit 400 is less than the fourth preset voltage V4, the third comparator U3 outputs a high level signal.

[0050] For example, Figure 2As shown, the operation unit 505 includes a first inverter INV1, a second inverter INV2, a third inverter INV3, a first NOR gate NOR1, a second NOR gate NOR2 and a third NOR gate NOR3. The input end of the first inverter INV1 is electrically connected to the first comparison unit 501, and the output end of the first inverter INV1 is electrically connected to the reference voltage unit 504, the input end of the second inverter INV2 and the first input end of the second NOR gate NOR2 respectively. The first input end of the first NOR gate NOR1 is electrically connected to the output end of the second inverter INV2, the reference voltage Unit 504 is electrically connected to the switch unit, the second input terminal of the first NOR gate NOR1 is electrically connected to the third comparison unit 503, the output terminal of the first NOR gate NOR1 is electrically connected to the first input terminal of the third NOR gate NOR3, the second input terminal of the second NOR gate NOR2 is electrically connected to the second comparison unit 502, the output terminal of the second NOR gate NOR2 is electrically connected to the second input terminal of the third NOR gate NOR3, the input terminal of the third inverter INV3 is electrically connected to the output terminal of the third NOR gate NOR3, and the output terminal of the third inverter INV3 is used to output the indication signal NTC.

[0051] Specifically, when the first comparator U1 outputs a high-level signal, the first inverter INV1 outputs a low-level signal, the second inverter INV2 outputs a high-level signal, and the first NOR gate NOR1 outputs a low-level signal. At this time, the third comparator U3 is shielded. When the first comparator U1 outputs a high-level signal and the second comparator U2 outputs a high-level signal, the second NOR gate NOR2 outputs a low-level signal, the third NOR gate NOR3 outputs a high-level signal, and the third inverter INV3 outputs a low-level signal. At this time, the temperature of the object to be measured is within the preset temperature range. When the first comparator U1 outputs a high-level signal and the second comparator U2 outputs a low-level signal, the second NOR gate NOR2 outputs a high-level signal, the third NOR gate NOR3 outputs a low-level signal, and the third inverter INV3 outputs a high-level signal. At this time, it indicates that the temperature of the object to be measured exceeds the preset temperature range.

[0052] When the first comparator U1 outputs a low-level signal, the first inverter INV1 outputs a high-level signal, the second inverter INV2 outputs a low-level signal, and the second NOR gate NOR2 outputs a low-level signal. At this time, the second comparator U2 is shielded. When the first comparator U1 outputs a low-level signal and the third comparator U3 outputs a high-level signal, the first NOR gate NOR1 outputs a low-level signal, the third NOR gate NOR3 outputs a high-level signal, and the third inverter INV3 outputs a low-level signal. At this time, the temperature of the object to be measured is within the preset temperature range. When the first comparator U1 outputs a low-level signal and the third comparator U3 outputs a low-level signal, the first NOR gate NOR1 outputs a high-level signal, the third NOR gate NOR3 outputs a low-level signal, and the third inverter INV3 outputs a high-level signal. At this time, the temperature of the object to be measured is within the preset temperature range.

[0053] For example, Figure 2 As shown, the reference voltage unit 504 includes a first transmission gate TG1 and a second transmission gate TG2, the first control end of the first transmission gate TG1 is electrically connected to the second control end of the second transmission gate TG2 and the output end of the first inverter INV1, the second control end of the first transmission gate TG1 is electrically connected to the first control end of the second transmission gate TG2, the output end of the second inverter INV2 and the first switch unit 300, the input end of the first transmission gate TG1 is electrically connected to a first voltage source for providing a first preset voltage V1, the output end of the first transmission gate TG1 is electrically connected to the output end of the second transmission gate TG2 and the inverting input end of the first comparator U1, and the input end of the second transmission gate TG2 is electrically connected to a second voltage source for providing a second preset voltage V2.

[0054] Specifically, in the initial state, the first comparator U1 outputs a low-level signal, the first switch unit 300 is in the on state, the first transmission gate TG1 is on, the second transmission gate TG2 is off, and the reference voltage applied to the inverting input terminal of the first comparator U1 is the first preset voltage V1. As the temperature of the object to be measured decreases, the resistance of the temperature acquisition unit 400 increases, and the acquisition voltage output by the temperature acquisition unit 400 increases. When the acquisition voltage exceeds the first preset voltage V1, the first comparator U1 outputs a high-level signal, the first switch unit 300 is off, the first transmission gate TG1 is off, and the second transmission gate TG2 is on. The reference voltage applied to the inverting input terminal of the first comparator U1 becomes the second preset voltage V2.

[0055] As the temperature of the object to be measured increases, the resistance of the temperature acquisition unit 400 decreases, and the acquisition voltage output by the temperature acquisition unit 400 decreases. When the acquisition voltage is less than the second preset voltage V2, the first comparator U1 outputs a low-level signal, turning on the first switch unit 300, turning on the first transmission gate TG1, and turning off the second transmission gate TG2. The reference voltage applied to the inverting input terminal of the first comparator U1 becomes the first preset voltage V1.

[0056] When the first switch unit 300 is on, the reference voltage applied to the inverting input terminal of the first comparator U1 is the first preset voltage V1. The first current source 100 and the second current source 200 simultaneously provide current to the temperature acquisition unit 400. The operating current of the temperature acquisition unit 400 is relatively high, and the acquisition voltage output by the temperature acquisition unit 400 is relatively high. When the first switch unit 300 is off, the reference voltage applied to the inverting input terminal of the first comparator U1 is the second preset voltage V2. Only the first current source 100 provides current to the temperature acquisition unit 400. The operating current of the temperature acquisition unit 400 is relatively low, and the acquisition voltage output by the temperature acquisition unit 400 is relatively low. Therefore, the first preset voltage V1 needs to be set to be greater than the second preset voltage V2.

[0057] For example, Figure 2 As shown, the first switch unit 300 includes a first switch tube PM1, a gate of the first switch tube PM1 is electrically connected to the output end of the second inverter INV2, a drain of the first switch tube PM1 is electrically connected to the second current source 200, and a source of the first switch tube PM1 is electrically connected to the temperature acquisition unit 400.

[0058] Specifically, the first switch tube PM1 is a P-type MOS tube. When the first comparator U1 outputs a high-level signal, the high-level signal output by the second inverter INV2 is loaded on the gate of the first switch tube PM1, and the first switch tube PM1 is disconnected. At this time, only the first current source 100 provides current to the temperature acquisition unit 400.

[0059] When the first comparator U1 outputs a low-level signal, the low-level signal output by the second inverter INV2 is loaded on the gate of the first switch tube PM1, and the first switch tube PM1 is turned on. At this time, the first current source 100 and the second current source 200 simultaneously provide current to the temperature acquisition unit 400.

[0060] For example, Figure 2As shown, the temperature acquisition unit 400 includes a first resistor R1 and a thermistor RNTC. The first end of the first resistor R1 is electrically connected to the first current source 100 and the source of the first switch tube PM1, respectively. The first end of the thermistor RNTC is electrically connected to the second end of the first resistor R1, the positive input end of the first comparator U1, the negative input end of the second comparator U2, and the negative input end of the third comparator U3, respectively. The second end of the thermistor RNTC is grounded.

[0061] Specifically, when the temperature of the object to be measured changes, the resistance of the thermistor RNTC changes accordingly, and thus the voltage at the first terminal of the thermistor RNTC also changes, thereby enabling the thermistor RNTC to detect the temperature of the object to be measured.

[0062] In order to clearly explain the working principle of the temperature detection circuit, a specific embodiment is given below. Figure 2 As shown, the temperature detection circuit is used to detect the temperature of the battery. Its detection temperature range is -10℃-60℃, the temperature coefficient of the thermistor RNTC is a negative temperature coefficient, the current of the first current source 100 is 20uA, the current of the second current source 200 is 60uA, the first preset voltage V1 is 850mV, the second preset voltage V2 is 200mV, the third preset voltage V3 is 1.14V, and the fourth preset voltage V4 is 208mV.

[0063] In the initial state, the first switch tube PM1 is in the on state. At this time, the current flowing through the thermistor RNTC is 80uA, the first transmission gate TG1 is on, the second transmission gate TG2 is off, and the voltage at the reverse input terminal of the first comparator U1 is 850mV.

[0064] When the battery temperature is below 25°C, the voltage output by the temperature acquisition unit 400 is greater than 850mV, the first comparator U1 outputs a high-level signal, the first switch PM1 turns off, the first transmission gate TG1 turns off, and the second transmission gate TG2 turns on. The voltage at the inverting input of the first comparator U1 is 200mV. At this point, the current flowing through the thermistor RNTC decreases to 20uA, and the voltage across the thermistor RNTC is greater than 200mV, allowing the first comparator U1 to maintain its high-level output signal.

[0065] When the battery temperature continues to drop, the resistance of the thermistor RNTC continues to increase, and the voltage of the thermistor RNTC also increases accordingly. The first comparator U1 keeps outputting a high-level signal. At this time, the output of the third comparator U3 is shielded, and the first AND-OR gate keeps outputting a low-level signal.

[0066] When the battery temperature is below -10°C, the voltage across thermistor RNTC is greater than 1.14V, the second comparator U2 outputs a low-level signal, the second NOR gate NOR2 outputs a high-level signal, the third NOR gate NOR3 outputs a low-level signal, and the third inverter INV3 outputs a high-level signal. Upon receiving the high-level signal from the third inverter INV3, the controller determines that the battery temperature is abnormal.

[0067] When the battery temperature rises above -10°C, the voltage across thermistor RNTC is less than 1.14V. The second comparator U2 outputs a high-level signal, the second NOR gate NOR2 outputs a low-level signal, the third NOR gate NOR3 outputs a high-level signal, and the third inverter INV3 outputs a low-level signal. Upon receiving the low-level signal from the third inverter INV3, the controller determines that the battery temperature is normal.

[0068] When the battery temperature exceeds 25°C, the voltage across the thermistor RNTC is less than 200mV. The first comparator U1 outputs a low-level signal, turning on the first switch PM1, the first transmission gate TG1, and the second transmission gate TG2. The voltage at the inverting input of the first comparator U1 is 850mV, and the current flowing through the thermistor RNTC increases from 20uA to 80uA. However, the voltage across the thermistor RNTC remains less than 850mV.

[0069] When the battery temperature exceeds 60°C, the voltage across thermistor RNTC is less than 208mV, the third comparator U3 outputs a low-level signal, the first NOR gate NOR1 outputs a high-level signal, the third NOR gate NOR3 outputs a low-level signal, and the third inverter INV3 outputs a high-level signal. Upon receiving the high-level signal from the third inverter INV3, the controller determines that the battery temperature is abnormal.

[0070] Thus, the temperature detection circuit realizes the temperature detection of the battery and can control the voltage range of the thermistor RNTC not to be too large and maintain it within the preset range, so that the difference between the first preset voltage V1, the second preset voltage V2, the third preset voltage V3 and the fourth preset voltage V4 is relatively small. The system's original power supply system can provide it, and there is no need to add an additional voltage source, which reduces the power consumption and production cost of the temperature detection circuit.

[0071] like Figure 3As shown, the temperature detection circuit further includes a second switch unit 600, a second logic unit 700, and a latch unit 800. The input end of the second switch unit 600 is electrically connected to the first current source 100 and the first switch unit 300, respectively. The output end of the second switch unit 600 is electrically connected to the temperature acquisition unit 400. The control end of the second switch unit 600 is electrically connected to the second logic unit 700. The second logic unit 700 is electrically connected to the first logic unit 500 and the latch unit 800, respectively. The latch unit 800 is electrically connected to the first logic unit 500.

[0072] Specifically, the second logic unit 700 is configured to receive an enable signal EN sent by the controller and, based on the enable signal EN, output a third control signal and a fourth control signal having opposite levels. The third control signal and the enable signal EN have the same level, and the fourth control signal is configured to control the second switch unit 600 to be turned on or off. The latch unit 800 is configured to latch the indication signal NTC based on the third control signal.

[0073] When the second logic unit 700 controls the second switch unit 600 to be off based on the fourth control signal output by the enable signal EN, the first current source 100 and the second current source 200 are unable to provide current to the temperature acquisition unit 400, causing the temperature acquisition unit 400 to not operate, and the latch unit 800 latches the indication signal NTC of the previous cycle. When the second logic unit 700 controls the second switch unit 600 to be on based on the fourth control signal output by the enable signal EN, the first current source 100 and the second current source 200 are able to provide current to the temperature acquisition unit 400, causing the temperature acquisition unit 400 to operate, and the latch unit 800 updates the indication signal NTC. This enables the temperature detection circuit to operate periodically rather than continuously, thereby reducing the power consumption of the temperature detection circuit.

[0074] For example, Figure 3 As shown, the second logic unit 700 includes a fourth inverter INV4, a fifth inverter INV5 and a delayer Y1, the input end of the fourth inverter INV4 is used to receive the enable signal EN, the output end of the fourth inverter INV4 is electrically connected to the second switch unit 600 and the input end of the fifth inverter INV5, respectively, the output end of the fifth inverter INV5 is electrically connected to the input end of the delayer Y1 and the first logic unit 500, and the output end of the delayer Y1 is electrically connected to the latch unit 800.

[0075] Specifically, when the enable signal EN is a high-level signal, the fourth inverter INV4 outputs a low-level signal, the fifth inverter INV5 outputs a high-level signal, the delayer Y1 delays the preset time to output the high-level signal, the second switch unit 600 is turned on, the temperature detection circuit outputs the indication signal NTC according to the temperature value of the object to be measured, and the latch unit 800 updates the output indication signal NTC.

[0076] When the enable signal EN is a low level signal, the fourth inverter INV4 outputs a high level signal, the fifth inverter INV5 outputs a low level signal, the delayer Y1 delays the preset time to output a low level signal, the second switch unit 600 is disconnected, the temperature detection circuit does not work, and the latch unit 800 latches the indication signal NTC of the previous cycle.

[0077] For example, Figure 3 As shown, the latch unit 800 includes a latch D1, a data input terminal of the latch D1 is electrically connected to the first logic unit 500, a clock input terminal of the latch D1 is electrically connected to the output terminal of the delayer Y1, and an output terminal of the latch D1 is used to output the latched indication signal NTC.

[0078] Specifically, when the clock input of latch D1 receives a high-level signal, the signal output by the output of latch D1 is updated to indicate that the data input has received the indication signal NTC. When the clock input of latch D1 receives a low-level signal, the signal output by the output of latch D1 is the indication signal NTC of the previous cycle, completing the latching of the indication signal NTC. Latch D1 can be a D-type flip-flop.

[0079] The present application also discloses a power supply comprising a battery, a controller, and the aforementioned temperature detection circuit. The temperature acquisition unit is configured to acquire the battery temperature and output an indication signal indicating the battery temperature based on the battery temperature. The controller is configured to adjust the battery charging current based on the indication signal to regulate the battery temperature. The temperature detection circuit in this power supply prevents the temperature acquisition unit from outputting an excessively high acquisition voltage due to excessive resistance, thereby ensuring that the acquisition voltage output by the temperature acquisition unit remains within a preset range. This eliminates the need for an additional voltage source when performing voltage comparison analysis, thereby reducing the power consumption and production cost of the power supply.

[0080] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A temperature detection circuit, characterized in that: The device comprises a first current source, a second current source, a first switch unit, a temperature acquisition unit, and a first logic unit, wherein the first current source is electrically connected to the temperature acquisition unit, the second current source is electrically connected to the temperature acquisition unit via the first switch unit, and the first logic unit is electrically connected to the temperature acquisition unit and the first switch unit, respectively; The first current source is used to provide a first current to the temperature acquisition unit; The second current source is used to provide a second current to the temperature acquisition unit; the temperature acquisition unit is used to output an acquisition voltage according to the temperature of the object to be measured; The first logic unit is used to output an indication signal for indicating the temperature information of the object to be measured according to the collected voltage; The first logic unit is further configured to control the first switch unit to be turned on or off according to the collected voltage, so that the collected voltage is within a preset range; The first logic unit includes a first comparing unit, a second comparing unit, a third comparing unit, a reference voltage unit and an operation unit, the first comparing unit is electrically connected to the temperature acquisition unit, the reference voltage unit and the operation unit respectively, the second comparing unit is electrically connected to the temperature acquisition unit and the operation unit respectively, the third comparing unit is electrically connected to the temperature acquisition unit and the operation unit respectively, and the operation unit is electrically connected to the reference voltage unit and the first switch unit respectively; The first comparison unit is configured to output a first comparison signal based on a reference voltage and the collected voltage; the second comparison unit is configured to output a second comparison signal based on a third preset voltage and the collected voltage; the third comparison unit is configured to output a third comparison signal based on a fourth preset voltage and the collected voltage; the operation unit is configured to output a first control signal and a second control signal of opposite levels based on the first comparison signal, the first control signal and the first comparison signal being at the same level, and the first control signal being configured to control the first switch unit to be turned on or off; the operation unit is further configured to output an indication signal for indicating temperature information of the object to be measured based on the first comparison signal, the second comparison signal, and the third comparison signal; the reference voltage unit is configured to output the reference voltage based on the first control signal and the second control signal, the reference voltage being a first preset voltage or a second preset voltage; The operation unit includes a first inverter, a second inverter, a third inverter, a first NOR gate, a second NOR gate and a third NOR gate. The input end of the first inverter is electrically connected to the first comparison unit, the output end of the first inverter is electrically connected to the reference voltage unit, the input end of the second inverter and the first input end of the second NOR gate respectively, the first input end of the first NOR gate is electrically connected to the output end of the second inverter, the reference voltage unit and the switch unit respectively, the second input end of the first NOR gate is electrically connected to the third comparison unit, the output end of the first NOR gate is electrically connected to the first input end of the third NOR gate, the second input end of the second NOR gate is electrically connected to the second comparison unit, the output end of the second NOR gate is electrically connected to the second input end of the third NOR gate, the input end of the third inverter is electrically connected to the output end of the third NOR gate, and the output end of the third inverter is used to output the indication signal.

2. The temperature detection circuit according to claim 1, wherein: The first comparison unit includes a first comparator, a positive input end of the first comparator is electrically connected to the temperature acquisition unit, a negative input end of the first comparator is electrically connected to the reference voltage unit, and an output end of the first comparator is electrically connected to the operation unit.

3. The temperature detection circuit according to claim 1, wherein: The second comparison unit includes a second comparator, the positive input end of the second comparator is electrically connected to a third voltage source for providing the third preset voltage, the reverse input end of the second comparator is electrically connected to the temperature acquisition unit, and the output end of the third comparator is electrically connected to the operation unit.

4. The temperature detection circuit according to claim 1, wherein: The third comparison unit includes a third comparator, the positive input end of the third comparator is electrically connected to a fourth voltage source for providing the fourth preset voltage, the reverse input end of the third comparator is electrically connected to the temperature acquisition unit, and the output end of the third comparator is electrically connected to the operation unit.

5. The temperature detection circuit according to claim 1, wherein: The reference voltage unit includes a first transmission gate and a second transmission gate, wherein the first control end of the first transmission gate is electrically connected to the second control end of the second transmission gate and the output end of the first inverter, respectively, and the second control end of the first transmission gate is electrically connected to the first control end of the second transmission gate, the output end of the second inverter, and the first switch unit, respectively. The input end of the first transmission gate is electrically connected to a first voltage source for providing the first preset voltage, the output end of the first transmission gate is electrically connected to the output end of the second transmission gate and the inverting input end of the first comparator, respectively, and the input end of the second transmission gate is electrically connected to a second voltage source for providing the second preset voltage.

6. The temperature detection circuit according to claim 5, characterized in that: The first switching unit includes a first switching tube, a gate of the first switching tube is electrically connected to the output end of the second inverter, a drain of the first switching tube is electrically connected to the second current source, and a source of the first switching tube is electrically connected to the temperature acquisition unit.

7. The temperature detection circuit according to claim 6, characterized in that: The temperature acquisition unit includes a first resistor and a thermistor, wherein the first end of the first resistor is electrically connected to the first current source and the source of the first switching tube respectively, the first end of the thermistor is electrically connected to the second end of the first resistor, the positive input end of the first comparator, the reverse input end of the second comparator, and the reverse input end of the third comparator respectively, and the second end of the thermistor is grounded.

8. The temperature detection circuit according to any one of claims 1 to 7, characterized in that: The temperature detection circuit further includes a second switch unit, a second logic unit and a latch unit; The input end of the second switch unit is electrically connected to the first current source and the first switch unit respectively, the output end of the second switch unit is electrically connected to the temperature acquisition unit, the control end of the second switch unit is electrically connected to the second logic unit, the second logic unit is electrically connected to the first logic unit and the latch unit respectively, and the latch unit is electrically connected to the first logic unit; The second logic unit is used to receive an enable signal and output a third control signal and a fourth control signal with opposite levels according to the enable signal, the third control signal and the enable signal have the same level, and the fourth control signal is used to control the second switch unit to be turned on or off; the latch unit is used to latch the indication signal according to the third control signal.

9. The temperature detection circuit according to claim 8, characterized in that: The second logic unit includes a fourth inverter, a fifth inverter and a delay unit, the input end of the fourth inverter is used to receive the enable signal, the output end of the fourth inverter is electrically connected to the second switch unit and the input end of the fifth inverter respectively, the output end of the fifth inverter is electrically connected to the input end of the delay unit and the first logic unit respectively, and the output end of the delay unit is electrically connected to the latch unit.

10. The temperature detection circuit according to claim 9, wherein: The latch unit includes a latch, a data input end of the latch is electrically connected to the first logic unit, a clock input end of the latch is electrically connected to the output end of the delayer, and an output end of the latch is used to output the latched indication signal.

11. A power supply, characterized in that: The invention comprises a battery, a controller and a temperature detection circuit according to any one of claims 1 to 10, wherein the temperature acquisition unit is used to acquire the temperature of the battery and output an indication signal for indicating the temperature information of the battery according to the temperature of the battery, and the controller is used to adjust the temperature of the battery according to the indication signal.

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