CN118583317A - Temperature detection circuit, method and electronic equipment - Google Patents
Temperature detection circuit, method and electronic equipment Download PDFInfo
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Abstract
The application relates to temperature detection, a temperature detection circuit temporarily stores a first voltage signal at the output end of a temperature detection unit according to a temporary storage signal and outputs the first voltage signal as a second voltage signal by arranging a detection temporary storage unit; a signal processing unit is arranged, the change of the temperature is determined according to the first voltage signal and the second voltage signal, a temperature detection signal corresponding to the change of the temperature is output, and a control unit obtains a temperature value according to the temperature detection signal; and outputting a temporary storage signal when the temperature value changes, so that the detection temporary storage unit updates the second voltage signal, thereby updating the temperature change. Therefore, the temperature detection circuit provided by the embodiment of the application can realize the temperature detection function without using an analog-to-digital converter and a communication interface, so that the complexity and cost of software and hardware development are reduced.
Description
Technical Field
The application belongs to the technical field of electronic circuits, and particularly relates to a temperature detection circuit, a temperature detection method and electronic equipment.
Background
In some electronic products without a temperature sensor, if a complete set of temperature quantization circuit is required to be added, a temperature detection device, an analog-to-digital conversion circuit, a central processing unit and other modules are generally required to be formed, and the central processing unit is required to have a corresponding communication interface. However, the analog-digital conversion circuit of the temperature quantization circuit has high cost, depends on the application of a communication interface of the central processing unit, and needs to be realized by matching with an algorithm on software, thereby increasing the complexity and cost of software and hardware development.
Disclosure of Invention
The application aims to provide a temperature detection circuit, a temperature detection method and electronic equipment, and aims to solve the problems that conventional temperature detection depends on an analog-to-digital converter and a communication interface, and complexity and cost of software and hardware development are high.
In a first aspect, an embodiment of the present application provides a temperature detection circuit, including:
The temperature detection unit is used for sensing the temperature in real time and outputting a first voltage signal representing temperature change information;
the detection temporary storage unit is connected with the temperature detection unit and is used for receiving a temporary storage signal, temporarily storing the first voltage signal according to the temporary storage signal and outputting the first voltage signal as a second voltage signal;
The signal processing unit is connected with the temperature detection unit and the detection temporary storage unit and is used for determining the change of temperature according to the first voltage signal and the second voltage signal and outputting a temperature detection signal corresponding to the change of temperature;
And the control unit is connected with the detection temporary storage unit and the signal processing unit and is used for obtaining a temperature value according to the temperature detection signal and outputting the temporary storage signal when the temperature value changes so that the detection temporary storage unit updates the second voltage signal.
In one embodiment, the method further comprises:
the trigger calibration unit is connected with the temperature detection unit and the control unit and is used for outputting a trigger calibration signal when the current temperature is determined to be greater than or equal to the lowest monitoring temperature according to the first voltage signal;
the control unit is also used for outputting the temporary storage signal according to the trigger calibration signal.
In one embodiment, the control unit includes a trigger end, a control end, and a detection end:
the trigger end is connected with the trigger calibration unit and is used for receiving the trigger calibration signal;
The detection end is connected with the signal processing unit;
The control end is connected with the signal processing unit and the detection temporary storage unit and is used for outputting the temporary storage signal to the signal processing unit and the detection temporary storage unit according to the trigger calibration signal or the temperature detection signal;
The signal processing unit is further used for stopping outputting the temperature detection signal according to the temporary storage signal so that the detection end is restored to an initial state.
In one embodiment, the detection end of the control unit comprises a first detection end and a second detection end; the signal processing unit comprises a first output end connected with the first detection end and a second output end connected with the second detection end, the temperature detection signals comprise a first temperature detection signal output from the first output end and a second temperature detection signal output from the second output end, and the second temperature detection signal is a voltage component of the first temperature detection signal;
The initial level of the first detection end is a first level, and the initial level of the second detection end is a second level different from the first level;
the control unit is specifically further configured to:
And when the first temperature detection signal or the second temperature detection signal is switched to a level state, determining a change value of temperature, and outputting the temporary storage signal.
In one embodiment, the detection temporary storage unit comprises a first switch tube, a first capacitor and a first operational amplifier;
The first end of the first switching tube is connected with the temperature detection unit, the second end of the first switching tube is connected with the non-inverting input end of the first operational amplifier, and the control end is used for receiving the temporary storage signal; the first capacitor is connected between the non-inverting input end of the first operational amplifier and the ground; the inverting input end of the first operational amplifier is connected with the output end, and the output end of the first operational amplifier is used for outputting the second voltage signal.
In one embodiment, the signal processing unit includes a second operational amplifier, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, and a second switching tube;
the first end of the second resistor is connected with the temperature detection unit, the second end of the second resistor is connected with the inverting input end of the second operational amplifier and the first end of the third resistor, and the second end of the third resistor is connected with the output end of the second operational amplifier;
The first end of the fourth resistor is connected with the detection temporary storage unit, the second end of the fourth resistor is connected with the non-inverting input end of the second operational amplifier, the first end of the fifth resistor and the first end of the sixth resistor, the second end of the fifth resistor is grounded, and the second end of the sixth resistor is connected with the first working voltage;
the first end of the second switching tube is connected with the output end of the second operational amplifier, and the second end of the second switching tube is used as the first output end of the signal processing unit and is connected with the control unit; the control end of the second switching tube is connected with the control unit and is used for receiving the temporary storage signal;
The first end of the seventh resistor is connected with the second end of the second switching tube, and the second end of the seventh resistor is connected with the second output end serving as the signal processing unit and the control unit; the eighth resistor is connected between the second end of the seventh resistor and ground.
In one embodiment, the trigger calibration unit includes a third switching tube, a ninth resistor, a tenth resistor, an eleventh resistor, and a twelfth resistor;
The first end of the ninth resistor is connected with the temperature detection unit, the second end of the ninth resistor is connected with the first end of the tenth resistor and the first end of the eleventh resistor, the second end of the tenth resistor is grounded, the second end of the eleventh resistor is connected with the control end of the third switching tube, the first end of the third switching tube is used as the output end of the trigger calibration unit and is connected with the control unit, and the second end of the third switching tube is grounded; the first end of the third switching tube is also connected with a second working voltage through the twelfth resistor.
In a second aspect, an embodiment of the present application further provides a temperature detection method, including:
sensing the temperature in real time to obtain a first voltage signal representing temperature information;
receiving and reading the first voltage signal according to the temporary storage signal, temporarily storing the first voltage signal, and outputting the temporarily stored first voltage signal as a second voltage signal;
determining a change in temperature from the first voltage signal and the second voltage signal, and outputting a temperature detection signal corresponding to the change in temperature;
and obtaining a temperature value according to the temperature detection signal, and outputting the temporary storage signal when the temperature value changes.
In one embodiment, before the receiving and reading the first voltage signal according to the temporary storage signal and temporary storing, the method further includes:
and triggering and outputting the temporary storage signal when the current temperature is determined to be greater than or equal to the lowest monitoring temperature according to the first voltage signal.
In one embodiment, the temperature detection signal includes a first temperature detection signal and a second temperature detection signal, the second temperature detection signal being a voltage component of the first temperature detection signal, the temperature detection method further including:
And when the first temperature detection signal or the second temperature detection signal is switched to a level state, determining a change value of temperature, and outputting the temporary storage signal.
In a third aspect, an embodiment of the present application further provides an electronic device, including the temperature detection circuit as described above.
Compared with the related art, the embodiment of the application has the beneficial effects that:
According to the temperature detection circuit provided by the embodiment of the application, the detection temporary storage unit is arranged, and the first voltage signal at the output end of the temperature detection unit is temporarily stored according to the temporary storage signal and is output as the second voltage signal; a signal processing unit is arranged, the change of the temperature is determined according to the first voltage signal and the second voltage signal, a temperature detection signal corresponding to the change of the temperature is output, and a control unit obtains a temperature value according to the temperature detection signal; and outputting a temporary storage signal when the temperature value changes, so that the detection temporary storage unit updates the second voltage signal, thereby updating the temperature change. Therefore, the temperature detection circuit provided by the embodiment of the application can realize the temperature detection function without using an analog-to-digital converter and a communication interface, so that the complexity and cost of software and hardware development are reduced.
Drawings
FIG. 1 is a schematic diagram of a temperature detecting circuit according to an embodiment of the present application;
FIG. 2 is a schematic diagram of a temperature detecting circuit according to an embodiment of the present application;
FIG. 3 is a circuit diagram of an exemplary temperature detection circuit according to an embodiment of the present application;
FIG. 4 is a diagram showing a deviation between a temperature count and an actual temperature of a temperature detection circuit according to an embodiment of the present application;
FIG. 5 is a graph showing the difference between the actual temperature and the temperature count result of an example of a temperature detection circuit according to an embodiment of the present application;
FIG. 6 is a logic flow diagram of temperature counting for a temperature detection circuit according to an embodiment of the present application.
Detailed Description
In order to make the technical problems, technical schemes and beneficial effects to be solved more clear, the application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.
It will be understood that when an element is referred to as being "mounted" or "disposed" on another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.
It is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are merely for convenience in describing and simplifying the description based on the orientation or positional relationship shown in the drawings, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the application.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.
Referring to fig. 1, an embodiment of the present application provides a temperature detection circuit, including: a temperature detecting unit 110, a detecting temporary storage unit 120, a signal processing unit 130 and a control unit 140.
The temperature detection unit 110 is configured to sense a temperature in real time and output a first voltage signal V 1 representing temperature information; the detecting temporary storage unit 120 is connected with the temperature detecting unit 110, and is used for receiving the temporary storage signal V 0, temporarily storing the first voltage signal V 1 according to the temporary storage signal V 0 and outputting the first voltage signal V 3; the signal processing unit 130 is connected to the temperature detecting unit 110 and the detecting temporary storage unit 120, and is configured to determine a change in temperature according to the first voltage signal V 1 and the second voltage signal V 3, and output a temperature detecting signal corresponding to the change in temperature; the control unit 140 is connected to the detection temporary storage unit 120 and the signal processing unit 130, and is configured to obtain a temperature value according to the temperature detection signal, and output a temporary storage signal V 0 when the temperature value changes, so that the detection temporary storage unit 120 updates the second voltage signal V 3.
Wherein the temperature detection unit 110 comprises a conventional temperature sensing device. The detecting and temporarily storing unit 120 specifically reads the current first voltage signal V 1 and temporarily stores the current first voltage signal V 0, and reads the first voltage signal V 1 and temporarily stores the current first voltage signal V 3 when the next temporary storage signal V 0 arrives, so that the second voltage signal V 3 is updated. It is understood that the voltage values of the first voltage signal V 1 and the second voltage signal V 3 may be the same or proportional. The second voltage signal V 3 is the first voltage signal V 1 output and temporarily stored by the temperature detecting unit 110 at the previous time, the signal processing unit 130 compares the first voltage signal V 1 output by the temperature detecting unit 110 and temporarily stored and output by the detecting and temporarily storing unit 120 at the previous time with the second voltage signal V 3, and determines and outputs a temperature detecting signal corresponding to the trend and the variation of the temperature according to the difference value between the first voltage signal V and the second voltage signal V 3. The control unit 140 may determine the current temperature value according to the temperature detection signal at a certain temperature threshold.
Wherein it may be determined whether the currently detected temperature is above a temperature threshold based on the magnitude of the first voltage signal V 1. For example, the voltage value of the first voltage signal V 1 is 4.8V, and the corresponding temperature threshold is 50 ℃.
Referring to fig. 2, in one embodiment, the temperature detection circuit further includes a trigger calibration unit 150. The trigger calibration unit 150 is connected to the temperature detection unit 110 and the control unit 140, and is configured to output a trigger calibration signal V 8 when determining that the current temperature is greater than or equal to the minimum monitored temperature according to the first voltage signal V 1; the control unit 140 is further configured to output a temporary storage signal V 0 according to the trigger calibration signal V 8.
When the current temperature is positively correlated with the first voltage signal V 1, the calibration unit 150 is triggered to determine that the current temperature is greater than or equal to the minimum monitored temperature when the first voltage signal V 1 is higher than the voltage value corresponding to the minimum monitored temperature. When the current temperature is inversely related to the first voltage signal V 1, the calibration unit 150 is triggered to determine that the current temperature is greater than or equal to the minimum monitored temperature when the first voltage signal V 1 is lower than the voltage value corresponding to the minimum monitored temperature.
Triggering the calibration unit 150 may enable the temperature detection circuit to implement accurate temperature calibration, and confirm that the current temperature is the lowest monitored temperature. The presence of the trigger calibration unit 150 also prevents the temperature detection circuit from deviating after multiple counts and realigns the actual temperature when returning to the lowest monitored temperature. In addition, the control unit 140 outputs the temporary storage signal V 0 according to the trigger calibration signal V 8, so that the temperature detection circuit starts to detect the temperature in real time above the minimum monitored temperature, and does not need to detect the temperature below the minimum monitored temperature, thereby releasing the system calculation force.
With continued reference to fig. 2, in one embodiment, the control unit 140 includes a trigger terminal GPIO4, a control terminal GPIO3, and a detection terminal GPIO1/GPIO2: the trigger terminal GPIO4 is connected to the trigger calibration unit 150 and is configured to receive a trigger calibration signal V 8; the detection terminal GPIO1/GPIO2 is connected with the signal processing unit 130; the control terminal GPIO3 is connected to the signal processing unit 130 and the detection temporary storage unit 120, and is configured to output a temporary storage signal V 0 to the signal processing unit 130 and the detection temporary storage unit 120 according to the trigger calibration signal V 8 or the temperature detection signal. The signal processing unit 130 is further configured to stop outputting the temperature detection signal according to the temporary storage signal V 0, so that the detection terminal GPIO1/GPIO2 of the control unit 140 is restored to the initial state.
The control unit 140 outputs a temporary storage signal V 0 (e.g. providing a high level/low level) once when the temperature value is determined to be changed according to the temperature detection signal, and the detection temporary storage unit 120 reads and temporarily stores the first voltage signal V 1 once again to update the second voltage signal V 3; the signal processing unit 130 stops outputting the temperature detection signal, so that the detection terminal GPIO1/GPIO2 of the control unit 140 is restored to the initial state, so that the current first voltage signal V 1 is compared with the updated second voltage signal V 3 by the signal processing unit 130, and the control unit 140 re-reads the temperature detection signal to determine a further change of the temperature. The technical solution of the embodiment of the present application only occupies the I/O port of the control unit 140, and does not need to occupy the communication interface.
In one embodiment, the control unit 140 is, for example, a microprocessor. The detection end of the control unit 140 includes a first detection end GPIO1 and a second detection end GPIO2; the signal processing unit 130 includes a first output terminal connected to the first detection terminal GPIO1 and a second output terminal connected to the second detection terminal GPIO2, the temperature detection signal includes a first temperature detection signal V 5 output from the first output terminal and a second temperature detection signal V 6 output from the second output terminal, and the second temperature detection signal V 6 is a voltage component of the first temperature detection signal V 5.
The initial level of the first detection terminal GPIO1 is a first level, and the initial level of the second detection terminal GPIO2 is a second level different from the first level.
The control unit 140 is specifically further configured to:
When the first temperature detection signal V 5 and the second temperature detection signal V 6 switch the level states, a temperature change value is determined, and a temporary storage signal V 0 is output.
Illustratively, when the current temperature is inversely related to the first voltage signal V 1, for example, the first level is high and the second level is low.
When the first temperature detection signal V 5 is at the first level and the second temperature detection signal V 6 is at the first level, a predetermined temperature rise (e.g., 1 ℃) is determined, and a temporary storage signal V 0, e.g., a low level, is output. Thus, the real-time detected temperature is the minimum monitored temperature or the temperature at the last moment is increased by a preset value.
When the first temperature detection signal V 5 is at the second level and the second temperature detection signal V 6 is at the second level, a predetermined temperature drop value (e.g., 1 ℃) is determined, and a temporary storage signal V 0 is output. Thus, the real-time detected temperature is the minimum monitored temperature or the temperature at the last moment is reduced by a preset value.
Illustratively, when the current temperature is positively correlated with the first voltage signal V 1, for example, the first level is high and the second level is low.
When the first temperature detection signal V 5 is at the second level and the second temperature detection signal V 6 is at the second level, a predetermined temperature rise (e.g., 1 ℃) is determined, and a temporary storage signal V 0, e.g., a low level, is output. Thus, the real-time detected temperature is the minimum monitored temperature or the temperature at the last moment is increased by a preset value.
When the first temperature detection signal V 5 is at the first level and the second temperature detection signal V 6 is at the first level, a predetermined temperature drop value (e.g., 1 ℃) is determined, and a temporary storage signal V 0 is output. Thus, the real-time detected temperature is the minimum monitored temperature or the temperature at the last moment is reduced by a preset value.
Referring to fig. 3, in one embodiment, the temperature detecting unit 110 includes a first resistor R1 and a thermistor RT1, the first resistor R1 and the thermistor RT1 are connected in series between a power source V DD and ground, and a series node is used as an output terminal of the temperature detecting unit 110.
Illustratively, the thermistor RT1 is a negative temperature coefficient thermistor, and the temperature detecting unit 110 is configured to convert temperature information into a first voltage signal V 1 that is inversely related to temperature. Thermistor RT1 is placed close to where there is a need for temperature detection so that the temperature can effectively characterize the actual temperature. When the temperature of the thermistor RT1 increases and the resistance becomes smaller, the first voltage signal V 1 is determined by the following formula:
In other embodiments, the thermistor RT1 is a positive temperature coefficient thermistor, and the temperature detection unit 110 is configured to convert the temperature signal into a first voltage signal V 1 that is inversely related to the temperature.
In one embodiment, the detection temporary storage unit 120 includes a first switching tube Q1, a first capacitor C1, and a first op-amp U1; the first end of the first switching tube Q1 is connected with the temperature detection unit 110, the second end of the first switching tube Q1 is connected with the non-inverting input end of the first operational amplifier U1, and the control end of the first switching tube Q1 is connected with the control end GPIO3 of the control unit 140 and is used for receiving the temporary storage signal V 0; the first capacitor C1 is connected between the non-inverting input end of the first operational amplifier U1 and the ground; the inverting input end of the first operational amplifier U1 is connected with the output end, and the output end of the first operational amplifier U1 is used for outputting a second voltage signal V 3.
The first switching tube Q1 includes a PMOS tube. The first operational amplifier U1 is used as a buffer for voltage following and impedance variation, and outputs the first voltage signal V 1 as the second voltage signal V 3 as an input of the signal processing unit 130.
In one embodiment, the signal processing unit 130 includes a second operational amplifier U2, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, and a second switching tube Q2.
The first end of the second resistor R2 is connected with the temperature detection unit 110, the second end of the second resistor R2 is connected with the inverting input end of the second operational amplifier U2 and the first end of the third resistor R3, and the second end of the third resistor R3 is connected with the output end of the second operational amplifier U2. The first end of the fourth resistor R4 is connected to the detection temporary storage unit 120, the second end of the fourth resistor R4 is connected to the non-inverting input end of the second op-amp U2, the first end of the fifth resistor R5 and the first end of the sixth resistor R6, the second end of the fifth resistor R5 is grounded, and the second end of the sixth resistor R6 is connected to the first operating voltage Vcc. The first end of the second switching tube Q2 is connected with the output end of the second operational amplifier U2, and the second end of the second switching tube Q2 is used as the first output end of the signal processing unit 130 and is connected with the control unit 140; the control terminal GPIO3 of the second switching tube Q2 is configured to receive the temporary storage signal V 0 and is connected to the control unit 140. The first end of the seventh resistor R7 is connected to the second end of the second switching tube Q2, and the second end of the seventh resistor R7 is connected to the control unit 140 as the second output end of the signal processing unit 130; the eighth resistor R8 is connected between the second end of the seventh resistor R7 and ground. Illustratively, the second switching tube Q2 includes an NMOS tube.
In one embodiment, the trigger calibration unit 150 includes a third switching tube Q3, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, and a twelfth resistor R12.
The first end of the ninth resistor R9 is connected with the temperature detection unit 110, the second end of the ninth resistor R9 is connected with the first end of the tenth resistor R10 and the first end of the eleventh resistor R11, the second end of the tenth resistor R10 is grounded, the second end of the eleventh resistor R11 is connected with the control end of the third switching tube Q3, the first end of the third switching tube Q3 serves as the output end of the trigger calibration unit 150 and is connected with the control unit 140, and the second end of the third switching tube Q3 is grounded; the first end of the third switching tube Q3 is further connected to the second operating voltage V DD through a twelfth resistor R12.
The third switching tube Q3 includes an NPN transistor or an NMOS transistor. The ninth resistor R9 and the tenth resistor R10 obtain a divided voltage V 7 by dividing the first voltage signal V 1. Taking the negative temperature coefficient thermistor as an example of the thermistor RT1, as the temperature increases, the resistance becomes smaller and the partial pressure V 7 becomes smaller. Therefore, the thermistor RT has a larger resistance at a relatively low temperature, the voltage division V 7 is higher than the conduction threshold of the third switching tube Q3, and when the third switching tube Q3 is turned on, the output end of the calibration unit 150 is triggered to output a low level, and the trigger end GPIO4 of the control unit 140 continuously detects as a low level, that is, no trigger calibration signal V 8 is output.
A reasonable resistor voltage division value is set for the ninth resistor R9 and the tenth resistor R10, so that after the temperature rises to reach the calibration temperature (for example, the minimum monitoring temperature) T C, when the voltage division V 7 becomes smaller than the on threshold of the third switching tube Q3, the third switching tube Q3 is turned off, and the calibration signal V 8 is triggered to be converted into a high level, that is, the calibration signal V 8 is triggered to be output. When the trigger terminal GPIO4 of the control unit 140 detects the trigger calibration signal V 8, accurate temperature calibration and temperature detection are achieved, and the current temperature is considered to be the calibration temperature T C. The simultaneous triggering of the calibration unit 150 prevents the control unit 140 from deviating after a number of counts and being able to realign the actual temperature when returning to the calibration temperature.
The hardware functions of the detection temporary storage unit 120 and the signal processing unit 130 are described as follows:
The first switching tube Q1 is a PMOS tube, and is controlled by the control terminal GPIO3 of the control unit 140, the low level (i.e. the temporary storage signal V 0) is turned on, and the control terminal GPIO3 is at a stable low level in the initial state, i.e. the first switching tube Q1 is continuously turned on initially, the first capacitor C1 is charged by the first voltage signal V 1, and the in-phase input terminal voltage V 2 of the first op-amp U1 is equal to the first voltage signal V 1. In this process, the detecting register unit 120 reads the first voltage signal V 1.
When the temperature rises and reaches the calibration temperature T C, after the trigger terminal GPIO4 of the control unit 140 detects the trigger calibration signal V 8, the control terminal GPIO3 outputs a high level (i.e. no temporary storage signal V 0 is output), and the first switching tube Q1 is turned off. At this time, the first operational amplifier U1 and the second operational amplifier U2 enter an operation stage, and the second operational amplifier U2 is formed by 3 input voltage operations: a first voltage signal V 1, a second voltage signal V 3, and a first operating voltage V CC.
The following holds true by the virtual break and the virtual short of the operational amplifier:
solving the above equation set, the relationship between the output voltage V 4 and 3 input voltages with respect to the signal processing unit 130 can be obtained:
in the design, the matching values of the resistors R2 to R6 are adjusted to enable:
Then:
in the above-mentioned relation, the first and second data are obtained, The output voltage V 4 of the signal processing unit 130 is constant, and after the first switching tube Q1 is turned off, the multiple of the difference between the second voltage signal V 3 and the first voltage signal V 1 (referred to as R 3/R2) is actually monitored, and the first voltage signal V 1 is updated in real time, and the second voltage signal V 3 is the previous sampled voltage value of the first voltage signal V 1. The corresponding relationship among the output voltage V 4, the first voltage signal V 1, the second voltage signal V 3 and the first operating voltage V CC is established.
At the same time we know: the following relationship holds at V 3＝V1, which is the voltage value in the initial state:
For the first detection terminal GPIO1, its input voltage: the first temperature detection signal V 5 is 0 when the second switching transistor Q2 is turned off, and is detected as a low level, and is the same as the output voltage V 4 when the second switching transistor Q2 is turned on. For the second detection terminal GPIO2, its input voltage: the second temperature detection signal V 6 is 0 when the second switching tube Q2 is turned off, and is detected as a low level, and the relationship with the first temperature detection signal V 5 when the second switching tube Q2 is turned on is:
for the initial state V 3＝V1, the second switching tube Q2 is turned on, assuming that the high level decision threshold of the GPIO1/GPIO2 of the control unit 140 is VIH and the low level decision threshold is VIL, the values of the first operating voltage V CC, the seventh resistor R7 and the eighth resistor R8 are reasonably configured, so that the first temperature detection signal V 5 > the high level decision threshold VIH and the second temperature detection signal V 6 < the low level decision threshold VIL in the initial state, the first detection terminal GPIO 1=1 and the second detection terminal GPIO 2=0.
Let us assume a temperature change of 1 ℃, a voltage difference Δv between the second voltage signal V 3 and the first voltage signal V 1.
When the temperature rises by 1 ℃, the second voltage signal V 3 > the first voltage signal V 1, the output voltage V 4 and the first temperature detection signal V 5 rise, the first detection terminal GPIO1 is continuously 1, but the second temperature detection signal V 6 of the second detection terminal GPIO2 is triggered to reach VIH, so that the second detection terminal GPIO 2=1, i.e. when GPIO 1=1 and GPIO 2=1, the temperature rise is known to be 1 ℃.
When the temperature decreases by 1 ℃, the second voltage signal V 3 < the first voltage signal V 1, the output voltage V 4 and the first temperature detection signal V 5 decrease, the second detection terminal GPIO2 is continuously 0, but the first temperature detection signal V 5 of the first detection terminal GPIO1 is triggered to decrease below VIL, so that the first detection terminal GPIO 1=0, i.e. when GPIO 1=0 and GPIO 2=0, the temperature is known to decrease by 1 ℃.
And when the temperature changes by 1 ℃, the control terminal GPIO3 is triggered to output a low level once (i.e. the temporary storage signal V 0), the first switch tube Q1 is turned on to align the voltages of the first voltage signal V 1 and the second voltage signal V 3, i.e. the first voltage signal V 1 is temporarily stored and output as the second voltage signal V 3, the second switch tube Q2 is turned off to zero the first temperature detection signal V 5 and the second temperature detection signal V 6, the control terminal GPIO3 is maintained at a high level, the difference value between the first voltage signal V 1 and the second voltage signal V 3 is monitored again, and the first detection terminal GPIO1 and the second detection terminal GPIO2 return to the original state GPIO 1=1 and GPIO 2=0. Because the change of temperature is very small to the voltage of the second voltage signal V 3, the recharging and discharging of the first capacitor C1 are very fast, so that the requirement can be met by rapidly switching the first switching tube Q1. If not, the initial state is disordered, for example, the second detecting terminal GPIO2 cannot return to the state 0 under the condition that the temperature continuously rises.
Up to this point, the levels of GPIO1 and GPIO2 as detection terminals are related, so that the control unit 140 can learn about the current temperature rising and falling. From the above, the voltage difference Δv between the first voltage signal V 1 and the second voltage signal V 3 is the variable of all the relationships, so that the temperature counting can be performed by using the voltage difference Δv to monitor, and the difference value is skillfully mapped into the logic levels of the detecting terminals GPIO1 and GPIO2, so long as the following relationships are established, the mapping relationship is completed:
The high level decision threshold VIH and the low level decision threshold are generally known as chip specifications of the control unit, and the above equation solution can be obtained as long as the voltage difference Δv is reasonably configured. The magnitude of the voltage difference DeltaV is determined by the magnitudes of the first resistor R1 and the thermistor RT1, so that the design flexibility is high.
In practical application, the counting condition of the technical scheme of the embodiment of the application in the continuous temperature rising process and the deviation of the practical temperature are shown in figure 4, the R square value can reach 0.99, and the accuracy is high.
In the practical test, let the power supply/second operating voltage V DD =3.3v, the first operating voltage V CC =4.4v, the first resistor r1=400 Ω, the second resistor r2=1 kΩ, the third resistor r3=100 kΩ, the fourth resistor r4=500 Ω, the fifth resistor r5=100 kΩ, the sixth resistor r6=100 kΩ, the ninth resistor r9=6 kΩ, the tenth resistor r10=3 kΩ, the seventh resistor r7=1.4kΩ, the eighth resistor r8=2 kΩ, and the actual temperature and temperature count result difference is shown in fig. 5 and is within an acceptable range.
After the above processing by the detection temporary storage unit 120 and the signal processing unit 130, the operation of the control unit 140 is greatly reduced, the rising and falling of the temperature can be known only by detecting each GPIO level, no complex communication and algorithm calculation processing are required, and the calculation force requirement of the control unit 140 is effectively reduced, and here, the logic relationship of the embodiment of the application is described by taking the negative temperature coefficient thermistor as an example by adopting the negative temperature coefficient thermistor as the thermistor RT1 in combination with fig. 3 and 6 and the GPIO port level state of the control unit 140, and the previous temperature is inversely related to the first voltage signal V 1.
(1) When the device is started, the temperature is lower, and when the calibration temperature T C is not reached, the trigger end GPIO 4=0 and the temperature monitoring is closed. As mentioned above, the control terminal GPIO3 is kept low (the temporary storage signal V 0), the first switching tube Q1 is turned on, the second switching tube Q2 is turned off, and the control unit 140 only needs to keep monitoring whether the level state of the trigger terminal GPIO4 appears gpio4=1.
(2) When GPIO 4=1 is detected, the trigger terminal GPIO3 immediately outputs a high level to start monitoring the voltage. At this time, an initial state of the monitoring state is entered: the first detection terminal GPIO 1=1 and the second detection terminal GPIO 2=0, and the initial temperature count of the control unit 140 is calibrated to T C.
(3) When GPIO 4=1, if the temperature rises by 1 ℃ to trigger the first detection terminal GPIO 1=1 and the second detection terminal GPIO 2=1, the temperature count of the control unit 140 is increased by 1, and the trigger terminal GPIO3 immediately outputs a low level (i.e. the temporary storage signal V 0) and then changes to a high level, so that the first detection terminal GPIO1 and the second detection terminal GPIO2 return to the initial state GPIO 1=1 and GPIO 2=0.
(4) When GPIO 4=1, if the temperature drops by 1 ℃ to trigger the first detection terminal GPIO 1=0 and the second detection terminal GPIO 2=0, the master control temperature count is reduced by 1, and the trigger terminal GPIO3 immediately outputs a low level and then changes to a high level, so that the first detection terminal GPIO1 and the second detection terminal GPIO2 return to the initial state GPIO 1=1 and GPIO 2=0.
(5) While gpio4=1, loops (3) and (4) are continuously cycled as long as the temperature does not trigger gpio4=0, only when gpio4=0 is detected, the master temperature count recalibrates to T C, and returns to step (1).
In a second aspect, an embodiment of the present application further provides a temperature detection method, including:
Step one, sensing temperature in real time to obtain a first voltage signal V1 representing temperature information;
Step two, the first voltage signal V1 is received and read according to the temporary storage signal V 0 for temporary storage, and the temporary storage first voltage signal V1 is output by the second voltage signal V3;
Determining a temperature change according to the first voltage signal V1 and the second voltage signal V3, and outputting a temperature detection signal corresponding to the temperature change;
and step four, obtaining a temperature value according to the temperature detection signal, and outputting a temporary storage signal V 0 when the temperature value changes.
In one embodiment, before receiving and reading the first voltage signal V1 according to the temporary storage signal V 0 and temporarily storing, the method further includes:
And triggering and outputting a temporary storage signal V 0 when the current temperature is determined to be greater than or equal to the minimum monitoring temperature according to the first voltage signal V1.
In one embodiment, the temperature detection signal includes a first temperature detection signal V5 and a second temperature detection signal V6, the second temperature detection signal V6 is a voltage component of the first temperature detection signal V5, and the temperature detection method further includes:
When the first temperature detection signal V5 or the second temperature detection signal V6 is switched to a level state, determining a temperature change value, and outputting a temporary storage signal V 0;
when the first temperature detection signal V5 is at the second level and the second temperature detection signal V6 is at the second level, the temperature drop preset value is determined, and the temporary storage signal V 0 is output.
In a third aspect, an embodiment of the present application further provides an electronic device, where the electronic device includes the temperature detection circuit as described above.
Compared with the related art, the embodiment of the application has the beneficial effects that:
1. The temperature quantification requirement of the control unit 140 such as a main control chip under the condition of lacking a communication interface is solved, and only a reasonably designed operational amplifier is needed to complete temperature monitoring, so that the circuit designs of a multistage comparator, a digital-to-analog conversion chip and the like are avoided, and the cost is extremely low.
2. In some low-end electronic products, under the condition that the main control chip lacks calculation power, the algorithm dependence on the main control chip is reduced, temperature quantization is realized by means of the design of the periphery of hardware, and the main control is only responsible for basic level monitoring tasks, so that the operation pressure of the main control chip is reduced, and the processing efficiency is improved.
3. Compared with the conventional temperature detection scheme, the temperature detection mode provided by the application has the main functions of hardware peripheral design, not only can identify high and low temperature thresholds, but also can use a hardware circuit to carry out temperature quantization, so that the design of a hardware operation unit is realized, the temperature difference value and the GPIO port level are used for mapping and converting into temperature change information which can be identified by a main control, and the information conversion between complex temperature change and simple GPIO level is realized.
4. The temperature counting accuracy in the scheme is higher, the actual temperature deviation is smaller, the circuit function design is ingenious, the visualization is strong, the implementation is easy, and the protection feasibility is high.
The above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and are intended to be included in the scope of the present application.
Claims (11)
1. A temperature detection circuit, comprising:
the temperature detection unit is used for sensing the temperature in real time and outputting a first voltage signal representing temperature information;
the detection temporary storage unit is connected with the temperature detection unit and is used for receiving a temporary storage signal, temporarily storing the first voltage signal according to the temporary storage signal and outputting the first voltage signal as a second voltage signal;
The signal processing unit is connected with the temperature detection unit and the detection temporary storage unit and is used for determining the change of temperature according to the first voltage signal and the second voltage signal and outputting a temperature detection signal corresponding to the change of temperature;
And the control unit is connected with the detection temporary storage unit and the signal processing unit and is used for obtaining a temperature value according to the temperature detection signal and outputting the temporary storage signal when the temperature value changes so that the detection temporary storage unit updates the second voltage signal.
2. The temperature detection circuit of claim 1, further comprising:
the trigger calibration unit is connected with the temperature detection unit and the control unit and is used for outputting a trigger calibration signal when the current temperature is determined to be greater than or equal to the lowest monitoring temperature according to the first voltage signal;
the control unit is also used for outputting the temporary storage signal according to the trigger calibration signal.
3. The temperature detection circuit of claim 2, wherein the control unit comprises a trigger terminal, a control terminal, and a detection terminal:
the trigger end is connected with the trigger calibration unit and is used for receiving the trigger calibration signal;
The detection end is connected with the signal processing unit;
The control end is connected with the signal processing unit and the detection temporary storage unit and is used for outputting the temporary storage signal to the signal processing unit and the detection temporary storage unit according to the trigger calibration signal or the temperature detection signal;
The signal processing unit is further used for stopping outputting the temperature detection signal according to the temporary storage signal so that the detection end is restored to an initial state.
4. A temperature detection circuit according to any one of claims 1 to 3, wherein the control unit includes a first detection terminal and a second detection terminal; the signal processing unit comprises a first output end connected with the first detection end and a second output end connected with the second detection end, the temperature detection signals comprise a first temperature detection signal output from the first output end and a second temperature detection signal output from the second output end, and the second temperature detection signal is a voltage component of the first temperature detection signal;
The initial level of the first detection end is a first level, and the initial level of the second detection end is a second level different from the first level;
the control unit is specifically further configured to:
And when the first temperature detection signal or the second temperature detection signal is switched to a level state, determining a change value of temperature, and outputting the temporary storage signal.
5. A temperature detection circuit according to any one of claims 1 to 3, wherein the detection register unit includes a first switching tube, a first capacitor, and a first op-amp;
The first end of the first switching tube is connected with the temperature detection unit, the second end of the first switching tube is connected with the non-inverting input end of the first operational amplifier, and the control end is used for receiving the temporary storage signal; the first capacitor is connected between the non-inverting input end of the first operational amplifier and the ground; the inverting input end of the first operational amplifier is connected with the output end, and the output end of the first operational amplifier is used for outputting the second voltage signal.
6. A temperature detection circuit according to any one of claims 1 to 3, wherein the signal processing unit includes a second operational amplifier, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, and a second switching tube;
the first end of the second resistor is connected with the temperature detection unit, the second end of the second resistor is connected with the inverting input end of the second operational amplifier and the first end of the third resistor, and the second end of the third resistor is connected with the output end of the second operational amplifier;
The first end of the fourth resistor is connected with the detection temporary storage unit, the second end of the fourth resistor is connected with the non-inverting input end of the second operational amplifier, the first end of the fifth resistor and the first end of the sixth resistor, the second end of the fifth resistor is grounded, and the second end of the sixth resistor is connected with the first working voltage;
the first end of the second switching tube is connected with the output end of the second operational amplifier, and the second end of the second switching tube is used as the first output end of the signal processing unit and is connected with the control unit; the control end of the second switching tube is connected with the control unit and is used for receiving the temporary storage signal;
The first end of the seventh resistor is connected with the second end of the second switching tube, and the second end of the seventh resistor is used as the second output end of the signal processing unit and is connected with the control unit; the eighth resistor is connected between the second end of the seventh resistor and ground.
7. A temperature detection circuit according to claim 2 or 3, wherein the trigger calibration unit comprises a third switching tube, a ninth resistor, a tenth resistor, an eleventh resistor and a twelfth resistor;
The first end of the ninth resistor is connected with the temperature detection unit, the second end of the ninth resistor is connected with the first end of the tenth resistor and the first end of the eleventh resistor, the second end of the tenth resistor is grounded, the second end of the eleventh resistor is connected with the control end of the third switching tube, the first end of the third switching tube is used as the output end of the trigger calibration unit and is connected with the control unit, and the second end of the third switching tube is grounded; the first end of the third switching tube is also connected with a second working voltage through the twelfth resistor.
8. A temperature detection method, comprising:
sensing the temperature in real time to obtain a first voltage signal representing temperature information;
receiving and reading the first voltage signal according to the temporary storage signal, temporarily storing the first voltage signal, and outputting the temporarily stored first voltage signal as a second voltage signal;
determining a change in temperature from the first voltage signal and the second voltage signal, and outputting a temperature detection signal corresponding to the change in temperature;
and obtaining a temperature value according to the temperature detection signal, and outputting the temporary storage signal when the temperature value changes.
9. The method of claim 8, further comprising, prior to said receiving and reading said first voltage signal according to a register signal and registering:
and triggering and outputting the temporary storage signal when the current temperature is determined to be greater than or equal to the lowest monitoring temperature according to the first voltage signal.
10. The temperature detection method according to claim 8, wherein the temperature detection signal includes a first temperature detection signal and a second temperature detection signal, the second temperature detection signal being a voltage component of the first temperature detection signal, the temperature detection method further comprising:
And when the first temperature detection signal or the second temperature detection signal is switched to a level state, determining a change value of temperature, and outputting the temporary storage signal.
11. An electronic device comprising the temperature detection circuit according to any one of claims 1 to 7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410669642.4A CN118583317A (en) | 2024-05-24 | 2024-05-24 | Temperature detection circuit, method and electronic equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410669642.4A CN118583317A (en) | 2024-05-24 | 2024-05-24 | Temperature detection circuit, method and electronic equipment |
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| Publication Number | Publication Date |
|---|---|
| CN118583317A true CN118583317A (en) | 2024-09-03 |
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| CN202410669642.4A Pending CN118583317A (en) | 2024-05-24 | 2024-05-24 | Temperature detection circuit, method and electronic equipment |
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| Country | Link |
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| CN (1) | CN118583317A (en) |
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